summaryrefslogtreecommitdiff
path: root/net/bluetooth/l2cap_core.c
AgeCommit message (Collapse)Author
2025-04-25Bluetooth: L2CAP: copy RX timestamp to new fragmentsPauli Virtanen
Copy timestamp too when allocating new skb for received fragment. Fixes missing RX timestamps with fragmentation. Fixes: 4d7ea8ee90e4 ("Bluetooth: L2CAP: Fix handling fragmented length") Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-04-16Bluetooth: l2cap: Process valid commands in too long frameFrédéric Danis
This is required for passing PTS test cases: - L2CAP/COS/CED/BI-14-C Multiple Signaling Command in one PDU, Data Truncated, BR/EDR, Connection Request - L2CAP/COS/CED/BI-15-C Multiple Signaling Command in one PDU, Data Truncated, BR/EDR, Disconnection Request The test procedure defined in L2CAP.TS.p39 for both tests is: 1. The Lower Tester sends a C-frame to the IUT with PDU Length set to 8 and Channel ID set to the correct signaling channel for the logical link. The Information payload contains one L2CAP_ECHO_REQ packet with Data Length set to 0 with 0 octets of echo data and one command packet and Data Length set as specified in Table 4.6 and the correct command data. 2. The IUT sends an L2CAP_ECHO_RSP PDU to the Lower Tester. 3. Perform alternative 3A, 3B, 3C, or 3D depending on the IUT’s response. Alternative 3A (IUT terminates the link): 3A.1 The IUT terminates the link. 3A.2 The test ends with a Pass verdict. Alternative 3B (IUT discards the frame): 3B.1 The IUT does not send a reply to the Lower Tester. Alternative 3C (IUT rejects PDU): 3C.1 The IUT sends an L2CAP_COMMAND_REJECT_RSP PDU to the Lower Tester. Alternative 3D (Any other IUT response): 3D.1 The Upper Tester issues a warning and the test ends. 4. The Lower Tester sends a C-frame to the IUT with PDU Length set to 4 and Channel ID set to the correct signaling channel for the logical link. The Information payload contains Data Length set to 0 with an L2CAP_ECHO_REQ packet with 0 octets of echo data. 5. The IUT sends an L2CAP_ECHO_RSP PDU to the Lower Tester. With expected outcome: In Steps 2 and 5, the IUT responds with an L2CAP_ECHO_RSP. In Step 3A.1, the IUT terminates the link. In Step 3B.1, the IUT does not send a reply to the Lower Tester. In Step 3C.1, the IUT rejects the PDU. In Step 3D.1, the IUT sends any valid response. Currently PTS fails with the following logs: Failed to receive ECHO RESPONSE. And HCI logs: > ACL Data RX: Handle 11 flags 0x02 dlen 20 L2CAP: Information Response (0x0b) ident 2 len 12 Type: Fixed channels supported (0x0003) Result: Success (0x0000) Channels: 0x000000000000002e L2CAP Signaling (BR/EDR) Connectionless reception AMP Manager Protocol L2CAP Signaling (LE) > ACL Data RX: Handle 11 flags 0x02 dlen 13 frame too long 08 01 00 00 08 02 01 00 aa ......... Cc: stable@vger.kernel.org Signed-off-by: Frédéric Danis <frederic.danis@collabora.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-04-10Bluetooth: l2cap: Check encryption key size on incoming connectionFrédéric Danis
This is required for passing GAP/SEC/SEM/BI-04-C PTS test case: Security Mode 4 Level 4, Responder - Invalid Encryption Key Size - 128 bit This tests the security key with size from 1 to 15 bytes while the Security Mode 4 Level 4 requests 16 bytes key size. Currently PTS fails with the following logs: - expected:Connection Response: Code: [3 (0x03)] Code Identifier: (lt)WildCard: Exists(gt) Length: [8 (0x0008)] Destination CID: (lt)WildCard: Exists(gt) Source CID: [64 (0x0040)] Result: [3 (0x0003)] Connection refused - Security block Status: (lt)WildCard: Exists(gt), but received:Connection Response: Code: [3 (0x03)] Code Identifier: [1 (0x01)] Length: [8 (0x0008)] Destination CID: [64 (0x0040)] Source CID: [64 (0x0040)] Result: [0 (0x0000)] Connection Successful Status: [0 (0x0000)] No further information available And HCI logs: < HCI Command: Read Encrypti.. (0x05|0x0008) plen 2 Handle: 14 Address: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.) > HCI Event: Command Complete (0x0e) plen 7 Read Encryption Key Size (0x05|0x0008) ncmd 1 Status: Success (0x00) Handle: 14 Address: 00:1B:DC:F2:24:10 (Vencer Co., Ltd.) Key size: 7 > ACL Data RX: Handle 14 flags 0x02 dlen 12 L2CAP: Connection Request (0x02) ident 1 len 4 PSM: 4097 (0x1001) Source CID: 64 < ACL Data TX: Handle 14 flags 0x00 dlen 16 L2CAP: Connection Response (0x03) ident 1 len 8 Destination CID: 64 Source CID: 64 Result: Connection successful (0x0000) Status: No further information available (0x0000) Fixes: 288c06973daa ("Bluetooth: Enforce key size of 16 bytes on FIPS level") Signed-off-by: Frédéric Danis <frederic.danis@collabora.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-03-25Bluetooth: L2CAP: add TX timestampingPauli Virtanen
Support TX timestamping in L2CAP sockets. Support MSG_ERRQUEUE recvmsg. For other than SOCK_STREAM L2CAP sockets, if a packet from sendmsg() is fragmented, only the first ACL fragment is timestamped. For SOCK_STREAM L2CAP sockets, use the bytestream convention and timestamp the last fragment and count bytes in tskey. Timestamps are not generated in the Enhanced Retransmission mode, as meaning of COMPLETION stamp is unclear if L2CAP layer retransmits. Signed-off-by: Pauli Virtanen <pav@iki.fi> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-03-25Bluetooth: L2CAP: convert timeouts to secs_to_jiffies()Easwar Hariharan
Commit b35108a51cf7 ("jiffies: Define secs_to_jiffies()") introduced secs_to_jiffies(). As the value here is a multiple of 1000, use secs_to_jiffies() instead of msecs_to_jiffies() for readability. Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-03-07Revert "Bluetooth: hci_core: Fix sleeping function called from invalid context"Luiz Augusto von Dentz
This reverts commit 4d94f05558271654670d18c26c912da0c1c15549 which has problems (see [1]) and is no longer needed since 581dd2dc168f ("Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating") has reworked the code where the original bug has been found. [1] Link: https://lore.kernel.org/linux-bluetooth/877c55ci1r.wl-tiwai@suse.de/T/#t Fixes: 4d94f0555827 ("Bluetooth: hci_core: Fix sleeping function called from invalid context") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-02-20Bluetooth: L2CAP: Fix L2CAP_ECRED_CONN_RSP responseLuiz Augusto von Dentz
L2CAP_ECRED_CONN_RSP needs to respond DCID in the same order received as SCID but the order is reversed due to use of list_add which actually prepend channels to the list so the response is reversed: > ACL Data RX: Handle 16 flags 0x02 dlen 26 LE L2CAP: Enhanced Credit Connection Request (0x17) ident 2 len 18 PSM: 39 (0x0027) MTU: 256 MPS: 251 Credits: 65535 Source CID: 116 Source CID: 117 Source CID: 118 Source CID: 119 Source CID: 120 < ACL Data TX: Handle 16 flags 0x00 dlen 26 LE L2CAP: Enhanced Credit Connection Response (0x18) ident 2 len 18 MTU: 517 MPS: 247 Credits: 3 Result: Connection successful (0x0000) Destination CID: 68 Destination CID: 67 Destination CID: 66 Destination CID: 65 Destination CID: 64 Also make sure the response don't include channels that are not on BT_CONNECT2 since the chan->ident can be set to the same value as in the following trace: < ACL Data TX: Handle 16 flags 0x00 dlen 12 LE L2CAP: LE Flow Control Credit (0x16) ident 6 len 4 Source CID: 64 Credits: 1 ... > ACL Data RX: Handle 16 flags 0x02 dlen 18 LE L2CAP: Enhanced Credit Connection Request (0x17) ident 6 len 10 PSM: 39 (0x0027) MTU: 517 MPS: 251 Credits: 255 Source CID: 70 < ACL Data TX: Handle 16 flags 0x00 dlen 20 LE L2CAP: Enhanced Credit Connection Response (0x18) ident 6 len 12 MTU: 517 MPS: 247 Credits: 3 Result: Connection successful (0x0000) Destination CID: 64 Destination CID: 68 Closes: https://github.com/bluez/bluez/issues/1094 Fixes: 9aa9d9473f15 ("Bluetooth: L2CAP: Fix responding with wrong PDU type") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2025-02-13Bluetooth: L2CAP: Fix corrupted list in hci_chan_delLuiz Augusto von Dentz
This fixes the following trace by reworking the locking of l2cap_conn so instead of only locking when changing the chan_l list this promotes chan_lock to a general lock of l2cap_conn so whenever it is being held it would prevents the likes of l2cap_conn_del to run: list_del corruption, ffff888021297e00->prev is LIST_POISON2 (dead000000000122) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:61! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 UID: 0 PID: 5896 Comm: syz-executor213 Not tainted 6.14.0-rc1-next-20250204-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__list_del_entry_valid_or_report+0x12c/0x190 lib/list_debug.c:59 Code: 8c 4c 89 fe 48 89 da e8 32 8c 37 fc 90 0f 0b 48 89 df e8 27 9f 14 fd 48 c7 c7 a0 c0 60 8c 4c 89 fe 48 89 da e8 15 8c 37 fc 90 <0f> 0b 4c 89 e7 e8 0a 9f 14 fd 42 80 3c 2b 00 74 08 4c 89 e7 e8 cb RSP: 0018:ffffc90003f6f998 EFLAGS: 00010246 RAX: 000000000000004e RBX: dead000000000122 RCX: 01454d423f7fbf00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff819f077c R09: 1ffff920007eded0 R10: dffffc0000000000 R11: fffff520007eded1 R12: dead000000000122 R13: dffffc0000000000 R14: ffff8880352248d8 R15: ffff888021297e00 FS: 00007f7ace6686c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7aceeeb1d0 CR3: 000000003527c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __list_del_entry_valid include/linux/list.h:124 [inline] __list_del_entry include/linux/list.h:215 [inline] list_del_rcu include/linux/rculist.h:168 [inline] hci_chan_del+0x70/0x1b0 net/bluetooth/hci_conn.c:2858 l2cap_conn_free net/bluetooth/l2cap_core.c:1816 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put+0x70/0xe0 net/bluetooth/l2cap_core.c:1830 l2cap_sock_shutdown+0xa8a/0x1020 net/bluetooth/l2cap_sock.c:1377 l2cap_sock_release+0x79/0x1d0 net/bluetooth/l2cap_sock.c:1416 __sock_release net/socket.c:642 [inline] sock_close+0xbc/0x240 net/socket.c:1393 __fput+0x3e9/0x9f0 fs/file_table.c:448 task_work_run+0x24f/0x310 kernel/task_work.c:227 ptrace_notify+0x2d2/0x380 kernel/signal.c:2522 ptrace_report_syscall include/linux/ptrace.h:415 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7aceeaf449 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7ace668218 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 00007f7acef39328 RCX: 00007f7aceeaf449 RDX: 000000000000000e RSI: 0000000020000100 RDI: 0000000000000004 RBP: 00007f7acef39320 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000004 R14: 00007f7ace668670 R15: 000000000000000b </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_del_entry_valid_or_report+0x12c/0x190 lib/list_debug.c:59 Code: 8c 4c 89 fe 48 89 da e8 32 8c 37 fc 90 0f 0b 48 89 df e8 27 9f 14 fd 48 c7 c7 a0 c0 60 8c 4c 89 fe 48 89 da e8 15 8c 37 fc 90 <0f> 0b 4c 89 e7 e8 0a 9f 14 fd 42 80 3c 2b 00 74 08 4c 89 e7 e8 cb RSP: 0018:ffffc90003f6f998 EFLAGS: 00010246 RAX: 000000000000004e RBX: dead000000000122 RCX: 01454d423f7fbf00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff819f077c R09: 1ffff920007eded0 R10: dffffc0000000000 R11: fffff520007eded1 R12: dead000000000122 R13: dffffc0000000000 R14: ffff8880352248d8 R15: ffff888021297e00 FS: 00007f7ace6686c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7acef05b08 CR3: 000000003527c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Reported-by: syzbot+10bd8fe6741eedd2be2e@syzkaller.appspotmail.com Tested-by: syzbot+10bd8fe6741eedd2be2e@syzkaller.appspotmail.com Fixes: b4f82f9ed43a ("Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
2025-02-13Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmdLuiz Augusto von Dentz
After the hci sync command releases l2cap_conn, the hci receive data work queue references the released l2cap_conn when sending to the upper layer. Add hci dev lock to the hci receive data work queue to synchronize the two. [1] BUG: KASAN: slab-use-after-free in l2cap_send_cmd+0x187/0x8d0 net/bluetooth/l2cap_core.c:954 Read of size 8 at addr ffff8880271a4000 by task kworker/u9:2/5837 CPU: 0 UID: 0 PID: 5837 Comm: kworker/u9:2 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: hci1 hci_rx_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 l2cap_build_cmd net/bluetooth/l2cap_core.c:2964 [inline] l2cap_send_cmd+0x187/0x8d0 net/bluetooth/l2cap_core.c:954 l2cap_sig_send_rej net/bluetooth/l2cap_core.c:5502 [inline] l2cap_sig_channel net/bluetooth/l2cap_core.c:5538 [inline] l2cap_recv_frame+0x221f/0x10db0 net/bluetooth/l2cap_core.c:6817 hci_acldata_packet net/bluetooth/hci_core.c:3797 [inline] hci_rx_work+0x508/0xdb0 net/bluetooth/hci_core.c:4040 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 5837: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] l2cap_conn_add+0xa9/0x8e0 net/bluetooth/l2cap_core.c:6860 l2cap_connect_cfm+0x115/0x1090 net/bluetooth/l2cap_core.c:7239 hci_connect_cfm include/net/bluetooth/hci_core.h:2057 [inline] hci_remote_features_evt+0x68e/0xac0 net/bluetooth/hci_event.c:3726 hci_event_func net/bluetooth/hci_event.c:7473 [inline] hci_event_packet+0xac2/0x1540 net/bluetooth/hci_event.c:7525 hci_rx_work+0x3f3/0xdb0 net/bluetooth/hci_core.c:4035 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 54: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x196/0x430 mm/slub.c:4761 l2cap_connect_cfm+0xcc/0x1090 net/bluetooth/l2cap_core.c:7235 hci_connect_cfm include/net/bluetooth/hci_core.h:2057 [inline] hci_conn_failed+0x287/0x400 net/bluetooth/hci_conn.c:1266 hci_abort_conn_sync+0x56c/0x11f0 net/bluetooth/hci_sync.c:5603 hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Reported-by: syzbot+31c2f641b850a348a734@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=31c2f641b850a348a734 Tested-by: syzbot+31c2f641b850a348a734@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis <eadavis@qq.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-12-12Bluetooth: hci_core: Fix sleeping function called from invalid contextLuiz Augusto von Dentz
This reworks hci_cb_list to not use mutex hci_cb_list_lock to avoid bugs like the bellow: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 4 locks held by kworker/u9:2/5070: #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline] #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline] #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335 #2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915 CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: hci0 hci_rx_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 __might_resched+0x5d4/0x780 kernel/sched/core.c:10187 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752 hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline] hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939 hci_event_func net/bluetooth/hci_event.c:7514 [inline] hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 </TASK> Reported-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com Tested-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614 Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-09-27Bluetooth: L2CAP: Fix uaf in l2cap_connectLuiz Augusto von Dentz
[Syzbot reported] BUG: KASAN: slab-use-after-free in l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949 Read of size 8 at addr ffff8880241e9800 by task kworker/u9:0/54 CPU: 0 UID: 0 PID: 54 Comm: kworker/u9:0 Not tainted 6.11.0-rc6-syzkaller-00268-g788220eee30d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: hci2 hci_rx_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 l2cap_connect.constprop.0+0x10d8/0x1270 net/bluetooth/l2cap_core.c:3949 l2cap_connect_req net/bluetooth/l2cap_core.c:4080 [inline] l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:4772 [inline] l2cap_sig_channel net/bluetooth/l2cap_core.c:5543 [inline] l2cap_recv_frame+0xf0b/0x8eb0 net/bluetooth/l2cap_core.c:6825 l2cap_recv_acldata+0x9b4/0xb70 net/bluetooth/l2cap_core.c:7514 hci_acldata_packet net/bluetooth/hci_core.c:3791 [inline] hci_rx_work+0xaab/0x1610 net/bluetooth/hci_core.c:4028 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 ... Freed by task 5245: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2256 [inline] slab_free mm/slub.c:4477 [inline] kfree+0x12a/0x3b0 mm/slub.c:4598 l2cap_conn_free net/bluetooth/l2cap_core.c:1810 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1822 [inline] l2cap_conn_del+0x59d/0x730 net/bluetooth/l2cap_core.c:1802 l2cap_connect_cfm+0x9e6/0xf80 net/bluetooth/l2cap_core.c:7241 hci_connect_cfm include/net/bluetooth/hci_core.h:1960 [inline] hci_conn_failed+0x1c3/0x370 net/bluetooth/hci_conn.c:1265 hci_abort_conn_sync+0x75a/0xb50 net/bluetooth/hci_sync.c:5583 abort_conn_sync+0x197/0x360 net/bluetooth/hci_conn.c:2917 hci_cmd_sync_work+0x1a4/0x410 net/bluetooth/hci_sync.c:328 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Reported-by: syzbot+c12e2f941af1feb5632c@syzkaller.appspotmail.com Tested-by: syzbot+c12e2f941af1feb5632c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c12e2f941af1feb5632c Fixes: 7b064edae38d ("Bluetooth: Fix authentication if acl data comes before remote feature evt") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-08-07Bluetooth: l2cap: always unlock channel in l2cap_conless_channel()Dmitry Antipov
Add missing call to 'l2cap_chan_unlock()' on receive error handling path in 'l2cap_conless_channel()'. Fixes: a24cce144b98 ("Bluetooth: Fix reference counting of global L2CAP channels") Reported-by: syzbot+45ac74737e866894acb0@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=45ac74737e866894acb0 Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-06-28Bluetooth: L2CAP: Fix deadlockLuiz Augusto von Dentz
This fixes the following deadlock introduced by 39a92a55be13 ("bluetooth/l2cap: sync sock recv cb and release") ============================================ WARNING: possible recursive locking detected 6.10.0-rc3-g4029dba6b6f1 #6823 Not tainted -------------------------------------------- kworker/u5:0/35 is trying to acquire lock: ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at: l2cap_sock_recv_cb+0x44/0x1e0 but task is already holding lock: ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at: l2cap_get_chan_by_scid+0xaf/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&chan->lock#2/1); lock(&chan->lock#2/1); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kworker/u5:0/35: #0: ffff888002b8a940 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x750/0x930 #1: ffff888002c67dd0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x44e/0x930 #2: ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at: l2cap_get_chan_by_scid+0xaf/0xd0 To fix the original problem this introduces l2cap_chan_lock at l2cap_conless_channel to ensure that l2cap_sock_recv_cb is called with chan->lock held. Fixes: 89e856e124f9 ("bluetooth/l2cap: sync sock recv cb and release") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-06-10Bluetooth: fix connection setup in l2cap_connectPauli Virtanen
The amp_id argument of l2cap_connect() was removed in commit 84a4bb6548a2 ("Bluetooth: HCI: Remove HCI_AMP support") It was always called with amp_id == 0, i.e. AMP_ID_BREDR == 0x00 (ie. non-AMP controller). In the above commit, the code path for amp_id != 0 was preserved, although it should have used the amp_id == 0 one. Restore the previous behavior of the non-AMP code path, to fix problems with L2CAP connections. Fixes: 84a4bb6548a2 ("Bluetooth: HCI: Remove HCI_AMP support") Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-06-10Bluetooth: L2CAP: Fix rejecting L2CAP_CONN_PARAM_UPDATE_REQLuiz Augusto von Dentz
This removes the bogus check for max > hcon->le_conn_max_interval since the later is just the initial maximum conn interval not the maximum the stack could support which is really 3200=4000ms. In order to pass GAP/CONN/CPUP/BV-05-C one shall probably enter values of the following fields in IXIT that would cause hci_check_conn_params to fail: TSPX_conn_update_int_min TSPX_conn_update_int_max TSPX_conn_update_peripheral_latency TSPX_conn_update_supervision_timeout Link: https://github.com/bluez/bluez/issues/847 Fixes: e4b019515f95 ("Bluetooth: Enforce validation on max value of connection interval") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-05-14Bluetooth: HCI: Remove HCI_AMP supportLuiz Augusto von Dentz
Since BT_HS has been remove HCI_AMP controllers no longer has any use so remove it along with the capability of creating AMP controllers. Since we no longer need to differentiate between AMP and Primary controllers, as only HCI_PRIMARY is left, this also remove hdev->dev_type altogether. Fixes: e7b02296fb40 ("Bluetooth: Remove BT_HS") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-05-14Bluetooth: L2CAP: Fix div-by-zero in l2cap_le_flowctl_init()Sungwoo Kim
l2cap_le_flowctl_init() can cause both div-by-zero and an integer overflow since hdev->le_mtu may not fall in the valid range. Move MTU from hci_dev to hci_conn to validate MTU and stop the connection process earlier if MTU is invalid. Also, add a missing validation in read_buffer_size() and make it return an error value if the validation fails. Now hci_conn_add() returns ERR_PTR() as it can fail due to the both a kzalloc failure and invalid MTU value. divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 67 Comm: kworker/u5:0 Tainted: G W 6.9.0-rc5+ #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: hci0 hci_rx_work RIP: 0010:l2cap_le_flowctl_init+0x19e/0x3f0 net/bluetooth/l2cap_core.c:547 Code: e8 17 17 0c 00 66 41 89 9f 84 00 00 00 bf 01 00 00 00 41 b8 02 00 00 00 4c 89 fe 4c 89 e2 89 d9 e8 27 17 0c 00 44 89 f0 31 d2 <66> f7 f3 89 c3 ff c3 4d 8d b7 88 00 00 00 4c 89 f0 48 c1 e8 03 42 RSP: 0018:ffff88810bc0f858 EFLAGS: 00010246 RAX: 00000000000002a0 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffff88810bc0f7c0 RDI: ffffc90002dcb66f RBP: ffff88810bc0f880 R08: aa69db2dda70ff01 R09: 0000ffaaaaaaaaaa R10: 0084000000ffaaaa R11: 0000000000000000 R12: ffff88810d65a084 R13: dffffc0000000000 R14: 00000000000002a0 R15: ffff88810d65a000 FS: 0000000000000000(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000100 CR3: 0000000103268003 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> l2cap_le_connect_req net/bluetooth/l2cap_core.c:4902 [inline] l2cap_le_sig_cmd net/bluetooth/l2cap_core.c:5420 [inline] l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5486 [inline] l2cap_recv_frame+0xe59d/0x11710 net/bluetooth/l2cap_core.c:6809 l2cap_recv_acldata+0x544/0x10a0 net/bluetooth/l2cap_core.c:7506 hci_acldata_packet net/bluetooth/hci_core.c:3939 [inline] hci_rx_work+0x5e5/0xb20 net/bluetooth/hci_core.c:4176 process_one_work kernel/workqueue.c:3254 [inline] process_scheduled_works+0x90f/0x1530 kernel/workqueue.c:3335 worker_thread+0x926/0xe70 kernel/workqueue.c:3416 kthread+0x2e3/0x380 kernel/kthread.c:388 ret_from_fork+0x5c/0x90 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- Fixes: 6ed58ec520ad ("Bluetooth: Use LE buffers for LE traffic") Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-05-14Bluetooth: compute LE flow credits based on recvbuf spaceSebastian Urban
Previously LE flow credits were returned to the sender even if the socket's receive buffer was full. This meant that no back-pressure was applied to the sender, thus it continued to send data, resulting in data loss without any error being reported. Furthermore, the amount of credits was essentially fixed to a small amount, leading to reduced performance. This is fixed by computing the number of returned LE flow credits based on the estimated available space in the receive buffer of an L2CAP socket. Consequently, if the receive buffer is full, no credits are returned until the buffer is read and thus cleared by user-space. Since the computation of available receive buffer space can only be performed approximately (due to sk_buff overhead) and the receive buffer size may be changed by user-space after flow credits have been sent, superfluous received data is temporary stored within l2cap_pinfo. This is necessary because Bluetooth LE provides no retransmission mechanism once the data has been acked by the physical layer. If receive buffer space estimation is not possible at the moment, we fall back to providing credits for one full packet as before. This is currently the case during connection setup, when MPS is not yet available. Fixes: b1c325c23d75 ("Bluetooth: Implement returning of LE L2CAP credits") Signed-off-by: Sebastian Urban <surban@surban.net> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-05-14Bluetooth: L2CAP: Avoid -Wflex-array-member-not-at-end warningsGustavo A. R. Silva
-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. There are currently a couple of objects (`req` and `rsp`), in a couple of structures, that contain flexible structures (`struct l2cap_ecred_conn_req` and `struct l2cap_ecred_conn_rsp`), for example: struct l2cap_ecred_rsp_data { struct { struct l2cap_ecred_conn_rsp rsp; __le16 scid[L2CAP_ECRED_MAX_CID]; } __packed pdu; int count; }; in the struct above, `struct l2cap_ecred_conn_rsp` is a flexible structure: struct l2cap_ecred_conn_rsp { __le16 mtu; __le16 mps; __le16 credits; __le16 result; __le16 dcid[]; }; So, in order to avoid ending up with a flexible-array member in the middle of another structure, we use the `struct_group_tagged()` (and `__struct_group()` when the flexible structure is `__packed`) helper to separate the flexible array from the rest of the members in the flexible structure: struct l2cap_ecred_conn_rsp { struct_group_tagged(l2cap_ecred_conn_rsp_hdr, hdr, ... the rest of members ); __le16 dcid[]; }; With the change described above, we now declare objects of the type of the tagged struct, in this example `struct l2cap_ecred_conn_rsp_hdr`, without embedding flexible arrays in the middle of other structures: struct l2cap_ecred_rsp_data { struct { struct l2cap_ecred_conn_rsp_hdr rsp; __le16 scid[L2CAP_ECRED_MAX_CID]; } __packed pdu; int count; }; Also, when the flexible-array member needs to be accessed, we use `container_of()` to retrieve a pointer to the flexible structure. We also use the `DEFINE_RAW_FLEX()` helper for a couple of on-stack definitions of a flexible structure where the size of the flexible-array member is known at compile-time. So, with these changes, fix the following warnings: net/bluetooth/l2cap_core.c:1260:45: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/l2cap_core.c:3740:45: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/l2cap_core.c:4999:45: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/l2cap_core.c:7116:47: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Link: https://github.com/KSPP/linux/issues/202 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-05-03Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeoutDuoming Zhou
There is a race condition between l2cap_chan_timeout() and l2cap_chan_del(). When we use l2cap_chan_del() to delete the channel, the chan->conn will be set to null. But the conn could be dereferenced again in the mutex_lock() of l2cap_chan_timeout(). As a result the null pointer dereference bug will happen. The KASAN report triggered by POC is shown below: [ 472.074580] ================================================================== [ 472.075284] BUG: KASAN: null-ptr-deref in mutex_lock+0x68/0xc0 [ 472.075308] Write of size 8 at addr 0000000000000158 by task kworker/0:0/7 [ 472.075308] [ 472.075308] CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.9.0-rc5-00356-g78c0094a146b #36 [ 472.075308] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4 [ 472.075308] Workqueue: events l2cap_chan_timeout [ 472.075308] Call Trace: [ 472.075308] <TASK> [ 472.075308] dump_stack_lvl+0x137/0x1a0 [ 472.075308] print_report+0x101/0x250 [ 472.075308] ? __virt_addr_valid+0x77/0x160 [ 472.075308] ? mutex_lock+0x68/0xc0 [ 472.075308] kasan_report+0x139/0x170 [ 472.075308] ? mutex_lock+0x68/0xc0 [ 472.075308] kasan_check_range+0x2c3/0x2e0 [ 472.075308] mutex_lock+0x68/0xc0 [ 472.075308] l2cap_chan_timeout+0x181/0x300 [ 472.075308] process_one_work+0x5d2/0xe00 [ 472.075308] worker_thread+0xe1d/0x1660 [ 472.075308] ? pr_cont_work+0x5e0/0x5e0 [ 472.075308] kthread+0x2b7/0x350 [ 472.075308] ? pr_cont_work+0x5e0/0x5e0 [ 472.075308] ? kthread_blkcg+0xd0/0xd0 [ 472.075308] ret_from_fork+0x4d/0x80 [ 472.075308] ? kthread_blkcg+0xd0/0xd0 [ 472.075308] ret_from_fork_asm+0x11/0x20 [ 472.075308] </TASK> [ 472.075308] ================================================================== [ 472.094860] Disabling lock debugging due to kernel taint [ 472.096136] BUG: kernel NULL pointer dereference, address: 0000000000000158 [ 472.096136] #PF: supervisor write access in kernel mode [ 472.096136] #PF: error_code(0x0002) - not-present page [ 472.096136] PGD 0 P4D 0 [ 472.096136] Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI [ 472.096136] CPU: 0 PID: 7 Comm: kworker/0:0 Tainted: G B 6.9.0-rc5-00356-g78c0094a146b #36 [ 472.096136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4 [ 472.096136] Workqueue: events l2cap_chan_timeout [ 472.096136] RIP: 0010:mutex_lock+0x88/0xc0 [ 472.096136] Code: be 08 00 00 00 e8 f8 23 1f fd 4c 89 f7 be 08 00 00 00 e8 eb 23 1f fd 42 80 3c 23 00 74 08 48 88 [ 472.096136] RSP: 0018:ffff88800744fc78 EFLAGS: 00000246 [ 472.096136] RAX: 0000000000000000 RBX: 1ffff11000e89f8f RCX: ffffffff8457c865 [ 472.096136] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88800744fc78 [ 472.096136] RBP: 0000000000000158 R08: ffff88800744fc7f R09: 1ffff11000e89f8f [ 472.096136] R10: dffffc0000000000 R11: ffffed1000e89f90 R12: dffffc0000000000 [ 472.096136] R13: 0000000000000158 R14: ffff88800744fc78 R15: ffff888007405a00 [ 472.096136] FS: 0000000000000000(0000) GS:ffff88806d200000(0000) knlGS:0000000000000000 [ 472.096136] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 472.096136] CR2: 0000000000000158 CR3: 000000000da32000 CR4: 00000000000006f0 [ 472.096136] Call Trace: [ 472.096136] <TASK> [ 472.096136] ? __die_body+0x8d/0xe0 [ 472.096136] ? page_fault_oops+0x6b8/0x9a0 [ 472.096136] ? kernelmode_fixup_or_oops+0x20c/0x2a0 [ 472.096136] ? do_user_addr_fault+0x1027/0x1340 [ 472.096136] ? _printk+0x7a/0xa0 [ 472.096136] ? mutex_lock+0x68/0xc0 [ 472.096136] ? add_taint+0x42/0xd0 [ 472.096136] ? exc_page_fault+0x6a/0x1b0 [ 472.096136] ? asm_exc_page_fault+0x26/0x30 [ 472.096136] ? mutex_lock+0x75/0xc0 [ 472.096136] ? mutex_lock+0x88/0xc0 [ 472.096136] ? mutex_lock+0x75/0xc0 [ 472.096136] l2cap_chan_timeout+0x181/0x300 [ 472.096136] process_one_work+0x5d2/0xe00 [ 472.096136] worker_thread+0xe1d/0x1660 [ 472.096136] ? pr_cont_work+0x5e0/0x5e0 [ 472.096136] kthread+0x2b7/0x350 [ 472.096136] ? pr_cont_work+0x5e0/0x5e0 [ 472.096136] ? kthread_blkcg+0xd0/0xd0 [ 472.096136] ret_from_fork+0x4d/0x80 [ 472.096136] ? kthread_blkcg+0xd0/0xd0 [ 472.096136] ret_from_fork_asm+0x11/0x20 [ 472.096136] </TASK> [ 472.096136] Modules linked in: [ 472.096136] CR2: 0000000000000158 [ 472.096136] ---[ end trace 0000000000000000 ]--- [ 472.096136] RIP: 0010:mutex_lock+0x88/0xc0 [ 472.096136] Code: be 08 00 00 00 e8 f8 23 1f fd 4c 89 f7 be 08 00 00 00 e8 eb 23 1f fd 42 80 3c 23 00 74 08 48 88 [ 472.096136] RSP: 0018:ffff88800744fc78 EFLAGS: 00000246 [ 472.096136] RAX: 0000000000000000 RBX: 1ffff11000e89f8f RCX: ffffffff8457c865 [ 472.096136] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88800744fc78 [ 472.096136] RBP: 0000000000000158 R08: ffff88800744fc7f R09: 1ffff11000e89f8f [ 472.132932] R10: dffffc0000000000 R11: ffffed1000e89f90 R12: dffffc0000000000 [ 472.132932] R13: 0000000000000158 R14: ffff88800744fc78 R15: ffff888007405a00 [ 472.132932] FS: 0000000000000000(0000) GS:ffff88806d200000(0000) knlGS:0000000000000000 [ 472.132932] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 472.132932] CR2: 0000000000000158 CR3: 000000000da32000 CR4: 00000000000006f0 [ 472.132932] Kernel panic - not syncing: Fatal exception [ 472.132932] Kernel Offset: disabled [ 472.132932] ---[ end Kernel panic - not syncing: Fatal exception ]--- Add a check to judge whether the conn is null in l2cap_chan_timeout() in order to mitigate the bug. Fixes: 3df91ea20e74 ("Bluetooth: Revert to mutexes from RCU list") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-05-03Bluetooth: L2CAP: Fix slab-use-after-free in l2cap_connect()Sungwoo Kim
Extend a critical section to prevent chan from early freeing. Also make the l2cap_connect() return type void. Nothing is using the returned value but it is ugly to return a potentially freed pointer. Making it void will help with backports because earlier kernels did use the return value. Now the compile will break for kernels where this patch is not a complete fix. Call stack summary: [use] l2cap_bredr_sig_cmd l2cap_connect ┌ mutex_lock(&conn->chan_lock); │ chan = pchan->ops->new_connection(pchan); <- alloc chan │ __l2cap_chan_add(conn, chan); │ l2cap_chan_hold(chan); │ list_add(&chan->list, &conn->chan_l); ... (1) └ mutex_unlock(&conn->chan_lock); chan->conf_state ... (4) <- use after free [free] l2cap_conn_del ┌ mutex_lock(&conn->chan_lock); │ foreach chan in conn->chan_l: ... (2) │ l2cap_chan_put(chan); │ l2cap_chan_destroy │ kfree(chan) ... (3) <- chan freed └ mutex_unlock(&conn->chan_lock); ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: slab-use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: slab-use-after-free in l2cap_connect+0xa67/0x11a0 net/bluetooth/l2cap_core.c:4260 Read of size 8 at addr ffff88810bf040a0 by task kworker/u3:1/311 Fixes: 73ffa904b782 ("Bluetooth: Move conf_{req,rsp} stuff to struct l2cap_chan") Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-04-24Bluetooth: hci_sync: Use advertised PHYs on hci_le_ext_create_conn_syncLuiz Augusto von Dentz
The extended advertising reports do report the PHYs so this store then in hci_conn so it can be later used in hci_le_ext_create_conn_sync to narrow the PHYs to be scanned since the controller will also perform a scan having a smaller set of PHYs shall reduce the time it takes to find and connect peers. Fixes: 288c90224eec ("Bluetooth: Enable all supported LE PHY by default") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-04-10Bluetooth: l2cap: Don't double set the HCI_CONN_MGMT_CONNECTED bitArchie Pusaka
The bit is set and tested inside mgmt_device_connected(), therefore we must not set it just outside the function. Fixes: eeda1bf97bb5 ("Bluetooth: hci_event: Fix not indicating new connection for BIG Sync") Signed-off-by: Archie Pusaka <apusaka@chromium.org> Reviewed-by: Manish Mandlik <mmandlik@chromium.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-03-06Bluetooth: hci_conn: Always use sk_timeo as conn_timeoutLuiz Augusto von Dentz
This aligns the use socket sk_timeo as conn_timeout when initiating a connection and then use it when scheduling the resulting HCI command, that way the command is actually aborted synchronously thus not blocking commands generated by hci_abort_conn_sync to inform the controller the connection is to be aborted. Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-03-06Bluetooth: Remove BT_HSLuiz Augusto von Dentz
High Speed, Alternate MAC and PHY (AMP) extension, has been removed from Bluetooth Core specification on 5.3: https://www.bluetooth.com/blog/new-core-specification-v5-3-feature-enhancements/ Fixes: 244bc377591c ("Bluetooth: Add BT_HS config option") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2024-02-28Bluetooth: Enforce validation on max value of connection intervalKai-Heng Feng
Right now Linux BT stack cannot pass test case "GAP/CONN/CPUP/BV-05-C 'Connection Parameter Update Procedure Invalid Parameters Central Responder'" in Bluetooth Test Suite revision GAP.TS.p44. [0] That was revoled by commit c49a8682fc5d ("Bluetooth: validate BLE connection interval updates"), but later got reverted due to devices like keyboards and mice may require low connection interval. So only validate the max value connection interval to pass the Test Suite, and let devices to request low connection interval if needed. [0] https://www.bluetooth.org/docman/handlers/DownloadDoc.ashx?doc_id=229869 Fixes: 68d19d7d9957 ("Revert "Bluetooth: validate BLE connection interval updates"") Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-12-22Bluetooth: L2CAP: Fix possible multiple reject sendFrédéric Danis
In case of an incomplete command or a command with a null identifier 2 reject packets will be sent, one with the identifier and one with 0. Consuming the data of the command will prevent it. This allows to send a reject packet for each corrupted command in a multi-command packet. Signed-off-by: Frédéric Danis <frederic.danis@collabora.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-12-15Bluetooth: L2CAP: Send reject on command corrupted requestFrédéric Danis
L2CAP/COS/CED/BI-02-C PTS test send a malformed L2CAP signaling packet with 2 commands in it (a connection request and an unknown command) and expect to get a connection response packet and a command reject packet. The second is currently not sent. Cc: stable@vger.kernel.org Signed-off-by: Frédéric Danis <frederic.danis@collabora.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-06-29Bluetooth: L2CAP: Fix use-after-freeZhengping Jiang
Fix potential use-after-free in l2cap_le_command_rej. Signed-off-by: Zhengping Jiang <jiangzp@google.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-06-05Bluetooth: L2CAP: Add missing checks for invalid DCIDSungwoo Kim
When receiving a connect response we should make sure that the DCID is within the valid range and that we don't already have another channel allocated for the same DCID. Missing checks may violate the specification (BLUETOOTH CORE SPECIFICATION Version 5.4 | Vol 3, Part A, Page 1046). Fixes: 40624183c202 ("Bluetooth: L2CAP: Add missing checks for invalid LE DCID") Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-06-05Bluetooth: Fix l2cap_disconnect_req deadlockYing Hsu
L2CAP assumes that the locks conn->chan_lock and chan->lock are acquired in the order conn->chan_lock, chan->lock to avoid potential deadlock. For example, l2sock_shutdown acquires these locks in the order: mutex_lock(&conn->chan_lock) l2cap_chan_lock(chan) However, l2cap_disconnect_req acquires chan->lock in l2cap_get_chan_by_scid first and then acquires conn->chan_lock before calling l2cap_chan_del. This means that these locks are acquired in unexpected order, which leads to potential deadlock: l2cap_chan_lock(c) mutex_lock(&conn->chan_lock) This patch releases chan->lock before acquiring the conn_chan_lock to avoid the potential deadlock. Fixes: a2a9339e1c9d ("Bluetooth: L2CAP: Fix use-after-free in l2cap_disconnect_{req,rsp}") Signed-off-by: Ying Hsu <yinghsu@chromium.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-04-23Bluetooth: L2CAP: fix "bad unlock balance" in l2cap_disconnect_rspMin Li
conn->chan_lock isn't acquired before l2cap_get_chan_by_scid, if l2cap_get_chan_by_scid returns NULL, then 'bad unlock balance' is triggered. Reported-by: syzbot+9519d6b5b79cf7787cf3@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/000000000000894f5f05f95e9f4d@google.com/ Signed-off-by: Min Li <lm0963hack@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-04-23Bluetooth: L2CAP: Delay identity address updatesLuiz Augusto von Dentz
This delays the identity address updates to give time for userspace to process the new address otherwise there is a risk that userspace creates a duplicated device if the MGMT event is delayed for some reason. Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-04-10Bluetooth: L2CAP: Fix use-after-free in l2cap_disconnect_{req,rsp}Luiz Augusto von Dentz
Similar to commit d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put"), just use l2cap_chan_hold_unless_zero to prevent referencing a channel that is about to be destroyed. Cc: stable@kernel.org Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Min Li <lm0963hack@gmail.com>
2023-03-23Bluetooth: L2CAP: Fix responding with wrong PDU typeLuiz Augusto von Dentz
L2CAP_ECRED_CONN_REQ shall be responded with L2CAP_ECRED_CONN_RSP not L2CAP_LE_CONN_RSP: L2CAP LE EATT Server - Reject - run Listening for connections New client connection with handle 0x002a Sending L2CAP Request from client Client received response code 0x15 Unexpected L2CAP response code (expected 0x18) L2CAP LE EATT Server - Reject - test failed > ACL Data RX: Handle 42 flags 0x02 dlen 26 LE L2CAP: Enhanced Credit Connection Request (0x17) ident 1 len 18 PSM: 39 (0x0027) MTU: 64 MPS: 64 Credits: 5 Source CID: 65 Source CID: 66 Source CID: 67 Source CID: 68 Source CID: 69 < ACL Data TX: Handle 42 flags 0x00 dlen 16 LE L2CAP: LE Connection Response (0x15) ident 1 len 8 invalid size 00 00 00 00 00 00 06 00 L2CAP LE EATT Server - Reject - run Listening for connections New client connection with handle 0x002a Sending L2CAP Request from client Client received response code 0x18 L2CAP LE EATT Server - Reject - test passed Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2023-02-09Bluetooth: L2CAP: Fix potential user-after-freeLuiz Augusto von Dentz
This fixes all instances of which requires to allocate a buffer calling alloc_skb which may release the chan lock and reacquire later which makes it possible that the chan is disconnected in the meantime. Fixes: a6a5568c03c4 ("Bluetooth: Lock the L2CAP channel when sending") Reported-by: Alexander Coffin <alex.coffin@matician.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2022-12-12Bluetooth: Add CONFIG_BT_LE_L2CAP_ECREDLuiz Augusto von Dentz
This adds CONFIG_BT_LE_L2CAP_ECRED which can be used to enable L2CAP Enhanced Credit Flow Control Mode by default, previously it was only possible to set it via module parameter (e.g. bluetooth.enable_ecred=1). Since L2CAP ECRED mode is required by the likes of EATT which is recommended for LE Audio this enables it by default. Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Tested-By: Tedd Ho-Jeong An <tedd.an@intel.com>
2022-12-02Bluetooth: L2CAP: Fix u8 overflowSungwoo Kim
By keep sending L2CAP_CONF_REQ packets, chan->num_conf_rsp increases multiple times and eventually it will wrap around the maximum number (i.e., 255). This patch prevents this by adding a boundary check with L2CAP_MAX_CONF_RSP Btmon log: Bluetooth monitor ver 5.64 = Note: Linux version 6.1.0-rc2 (x86_64) 0.264594 = Note: Bluetooth subsystem version 2.22 0.264636 @ MGMT Open: btmon (privileged) version 1.22 {0x0001} 0.272191 = New Index: 00:00:00:00:00:00 (Primary,Virtual,hci0) [hci0] 13.877604 @ RAW Open: 9496 (privileged) version 2.22 {0x0002} 13.890741 = Open Index: 00:00:00:00:00:00 [hci0] 13.900426 (...) > ACL Data RX: Handle 200 flags 0x00 dlen 1033 #32 [hci0] 14.273106 invalid packet size (12 != 1033) 08 00 01 00 02 01 04 00 01 10 ff ff ............ > ACL Data RX: Handle 200 flags 0x00 dlen 1547 #33 [hci0] 14.273561 invalid packet size (14 != 1547) 0a 00 01 00 04 01 06 00 40 00 00 00 00 00 ........@..... > ACL Data RX: Handle 200 flags 0x00 dlen 2061 #34 [hci0] 14.274390 invalid packet size (16 != 2061) 0c 00 01 00 04 01 08 00 40 00 00 00 00 00 00 04 ........@....... > ACL Data RX: Handle 200 flags 0x00 dlen 2061 #35 [hci0] 14.274932 invalid packet size (16 != 2061) 0c 00 01 00 04 01 08 00 40 00 00 00 07 00 03 00 ........@....... = bluetoothd: Bluetooth daemon 5.43 14.401828 > ACL Data RX: Handle 200 flags 0x00 dlen 1033 #36 [hci0] 14.275753 invalid packet size (12 != 1033) 08 00 01 00 04 01 04 00 40 00 00 00 ........@... Signed-off-by: Sungwoo Kim <iam@sung-woo.kim> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2022-11-02Bluetooth: L2CAP: Fix attempting to access uninitialized memoryLuiz Augusto von Dentz
On l2cap_parse_conf_req the variable efs is only initialized if remote_efs has been set. CVE: CVE-2022-42895 CC: stable@vger.kernel.org Reported-by: Tamás Koczka <poprdi@google.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Reviewed-by: Tedd Ho-Jeong An <tedd.an@intel.com>
2022-11-02Bluetooth: L2CAP: Fix l2cap_global_chan_by_psmLuiz Augusto von Dentz
l2cap_global_chan_by_psm shall not return fixed channels as they are not meant to be connected by (S)PSM. Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Reviewed-by: Tedd Ho-Jeong An <tedd.an@intel.com>
2022-11-02Bluetooth: L2CAP: Fix accepting connection request for invalid SPSMLuiz Augusto von Dentz
The Bluetooth spec states that the valid range for SPSM is from 0x0001-0x00ff so it is invalid to accept values outside of this range: BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A page 1059: Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges CVE: CVE-2022-42896 CC: stable@vger.kernel.org Reported-by: Tamás Koczka <poprdi@google.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Reviewed-by: Tedd Ho-Jeong An <tedd.an@intel.com>
2022-11-02Bluetooth: L2CAP: Fix memory leak in vhci_writeHawkins Jiawei
Syzkaller reports a memory leak as follows: ==================================== BUG: memory leak unreferenced object 0xffff88810d81ac00 (size 240): [...] hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff838733d9>] __alloc_skb+0x1f9/0x270 net/core/skbuff.c:418 [<ffffffff833f742f>] alloc_skb include/linux/skbuff.h:1257 [inline] [<ffffffff833f742f>] bt_skb_alloc include/net/bluetooth/bluetooth.h:469 [inline] [<ffffffff833f742f>] vhci_get_user drivers/bluetooth/hci_vhci.c:391 [inline] [<ffffffff833f742f>] vhci_write+0x5f/0x230 drivers/bluetooth/hci_vhci.c:511 [<ffffffff815e398d>] call_write_iter include/linux/fs.h:2192 [inline] [<ffffffff815e398d>] new_sync_write fs/read_write.c:491 [inline] [<ffffffff815e398d>] vfs_write+0x42d/0x540 fs/read_write.c:578 [<ffffffff815e3cdd>] ksys_write+0x9d/0x160 fs/read_write.c:631 [<ffffffff845e0645>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff845e0645>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84600087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd ==================================== HCI core will uses hci_rx_work() to process frame, which is queued to the hdev->rx_q tail in hci_recv_frame() by HCI driver. Yet the problem is that, HCI core may not free the skb after handling ACL data packets. To be more specific, when start fragment does not contain the L2CAP length, HCI core just copies skb into conn->rx_skb and finishes frame process in l2cap_recv_acldata(), without freeing the skb, which triggers the above memory leak. This patch solves it by releasing the relative skb, after processing the above case in l2cap_recv_acldata(). Fixes: 4d7ea8ee90e4 ("Bluetooth: L2CAP: Fix handling fragmented length") Link: https://lore.kernel.org/all/0000000000000d0b1905e6aaef64@google.com/ Reported-and-tested-by: syzbot+8f819e36e01022991cfa@syzkaller.appspotmail.com Signed-off-by: Hawkins Jiawei <yin31149@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2022-11-02Bluetooth: L2CAP: fix use-after-free in l2cap_conn_del()Zhengchao Shao
When l2cap_recv_frame() is invoked to receive data, and the cid is L2CAP_CID_A2MP, if the channel does not exist, it will create a channel. However, after a channel is created, the hold operation of the channel is not performed. In this case, the value of channel reference counting is 1. As a result, after hci_error_reset() is triggered, l2cap_conn_del() invokes the close hook function of A2MP to release the channel. Then l2cap_chan_unlock(chan) will trigger UAF issue. The process is as follows: Receive data: l2cap_data_channel() a2mp_channel_create() --->channel ref is 2 l2cap_chan_put() --->channel ref is 1 Triger event: hci_error_reset() hci_dev_do_close() ... l2cap_disconn_cfm() l2cap_conn_del() l2cap_chan_hold() --->channel ref is 2 l2cap_chan_del() --->channel ref is 1 a2mp_chan_close_cb() --->channel ref is 0, release channel l2cap_chan_unlock() --->UAF of channel The detailed Call Trace is as follows: BUG: KASAN: use-after-free in __mutex_unlock_slowpath+0xa6/0x5e0 Read of size 8 at addr ffff8880160664b8 by task kworker/u11:1/7593 Workqueue: hci0 hci_error_reset Call Trace: <TASK> dump_stack_lvl+0xcd/0x134 print_report.cold+0x2ba/0x719 kasan_report+0xb1/0x1e0 kasan_check_range+0x140/0x190 __mutex_unlock_slowpath+0xa6/0x5e0 l2cap_conn_del+0x404/0x7b0 l2cap_disconn_cfm+0x8c/0xc0 hci_conn_hash_flush+0x11f/0x260 hci_dev_close_sync+0x5f5/0x11f0 hci_dev_do_close+0x2d/0x70 hci_error_reset+0x9e/0x140 process_one_work+0x98a/0x1620 worker_thread+0x665/0x1080 kthread+0x2e4/0x3a0 ret_from_fork+0x1f/0x30 </TASK> Allocated by task 7593: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0xa9/0xd0 l2cap_chan_create+0x40/0x930 amp_mgr_create+0x96/0x990 a2mp_channel_create+0x7d/0x150 l2cap_recv_frame+0x51b8/0x9a70 l2cap_recv_acldata+0xaa3/0xc00 hci_rx_work+0x702/0x1220 process_one_work+0x98a/0x1620 worker_thread+0x665/0x1080 kthread+0x2e4/0x3a0 ret_from_fork+0x1f/0x30 Freed by task 7593: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_set_free_info+0x20/0x30 ____kasan_slab_free+0x167/0x1c0 slab_free_freelist_hook+0x89/0x1c0 kfree+0xe2/0x580 l2cap_chan_put+0x22a/0x2d0 l2cap_conn_del+0x3fc/0x7b0 l2cap_disconn_cfm+0x8c/0xc0 hci_conn_hash_flush+0x11f/0x260 hci_dev_close_sync+0x5f5/0x11f0 hci_dev_do_close+0x2d/0x70 hci_error_reset+0x9e/0x140 process_one_work+0x98a/0x1620 worker_thread+0x665/0x1080 kthread+0x2e4/0x3a0 ret_from_fork+0x1f/0x30 Last potentially related work creation: kasan_save_stack+0x1e/0x40 __kasan_record_aux_stack+0xbe/0xd0 call_rcu+0x99/0x740 netlink_release+0xe6a/0x1cf0 __sock_release+0xcd/0x280 sock_close+0x18/0x20 __fput+0x27c/0xa90 task_work_run+0xdd/0x1a0 exit_to_user_mode_prepare+0x23c/0x250 syscall_exit_to_user_mode+0x19/0x50 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 __kasan_record_aux_stack+0xbe/0xd0 call_rcu+0x99/0x740 netlink_release+0xe6a/0x1cf0 __sock_release+0xcd/0x280 sock_close+0x18/0x20 __fput+0x27c/0xa90 task_work_run+0xdd/0x1a0 exit_to_user_mode_prepare+0x23c/0x250 syscall_exit_to_user_mode+0x19/0x50 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put") Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2022-11-02Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sduMaxim Mikityanskiy
Fix the race condition between the following two flows that run in parallel: 1. l2cap_reassemble_sdu -> chan->ops->recv (l2cap_sock_recv_cb) -> __sock_queue_rcv_skb. 2. bt_sock_recvmsg -> skb_recv_datagram, skb_free_datagram. An SKB can be queued by the first flow and immediately dequeued and freed by the second flow, therefore the callers of l2cap_reassemble_sdu can't use the SKB after that function returns. However, some places continue accessing struct l2cap_ctrl that resides in the SKB's CB for a short time after l2cap_reassemble_sdu returns, leading to a use-after-free condition (the stack trace is below, line numbers for kernel 5.19.8). Fix it by keeping a local copy of struct l2cap_ctrl. BUG: KASAN: use-after-free in l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth Read of size 1 at addr ffff88812025f2f0 by task kworker/u17:3/43169 Workqueue: hci0 hci_rx_work [bluetooth] Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4)) print_report.cold (mm/kasan/report.c:314 mm/kasan/report.c:429) ? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth kasan_report (mm/kasan/report.c:162 mm/kasan/report.c:493) ? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth l2cap_rx (net/bluetooth/l2cap_core.c:7236 net/bluetooth/l2cap_core.c:7271) bluetooth ret_from_fork (arch/x86/entry/entry_64.S:306) </TASK> Allocated by task 43169: kasan_save_stack (mm/kasan/common.c:39) __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469) kmem_cache_alloc_node (mm/slab.h:750 mm/slub.c:3243 mm/slub.c:3293) __alloc_skb (net/core/skbuff.c:414) l2cap_recv_frag (./include/net/bluetooth/bluetooth.h:425 net/bluetooth/l2cap_core.c:8329) bluetooth l2cap_recv_acldata (net/bluetooth/l2cap_core.c:8442) bluetooth hci_rx_work (net/bluetooth/hci_core.c:3642 net/bluetooth/hci_core.c:3832) bluetooth process_one_work (kernel/workqueue.c:2289) worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2437) kthread (kernel/kthread.c:376) ret_from_fork (arch/x86/entry/entry_64.S:306) Freed by task 27920: kasan_save_stack (mm/kasan/common.c:39) kasan_set_track (mm/kasan/common.c:45) kasan_set_free_info (mm/kasan/generic.c:372) ____kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328) slab_free_freelist_hook (mm/slub.c:1780) kmem_cache_free (mm/slub.c:3536 mm/slub.c:3553) skb_free_datagram (./include/net/sock.h:1578 ./include/net/sock.h:1639 net/core/datagram.c:323) bt_sock_recvmsg (net/bluetooth/af_bluetooth.c:295) bluetooth l2cap_sock_recvmsg (net/bluetooth/l2cap_sock.c:1212) bluetooth sock_read_iter (net/socket.c:1087) new_sync_read (./include/linux/fs.h:2052 fs/read_write.c:401) vfs_read (fs/read_write.c:482) ksys_read (fs/read_write.c:620) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) Link: https://lore.kernel.org/linux-bluetooth/CAKErNvoqga1WcmoR3-0875esY6TVWFQDandbVZncSiuGPBQXLA@mail.gmail.com/T/#u Fixes: d2a7ac5d5d3a ("Bluetooth: Add the ERTM receive state machine") Fixes: 4b51dae96731 ("Bluetooth: Add streaming mode receive and incoming packet classifier") Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2022-09-29Bluetooth: L2CAP: Fix user-after-freeLuiz Augusto von Dentz
This uses l2cap_chan_hold_unless_zero() after calling __l2cap_get_chan_blah() to prevent the following trace: Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref *kref) Bluetooth: chan 0000000023c4974d Bluetooth: parent 00000000ae861c08 ================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:671 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400 kernel/locking/mutex.c:729 Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389 Link: https://lore.kernel.org/lkml/20220622082716.478486-1-lee.jones@linaro.org Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sungwoo Kim <iam@sung-woo.kim>
2022-09-19Bluetooth: L2CAP: initialize delayed works at l2cap_chan_create()Tetsuo Handa
syzbot is reporting cancel_delayed_work() without INIT_DELAYED_WORK() at l2cap_chan_del() [1], for CONF_NOT_COMPLETE flag (which meant to prevent l2cap_chan_del() from calling cancel_delayed_work()) is cleared by timer which fires before l2cap_chan_del() is called by closing file descriptor created by socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_L2CAP). l2cap_bredr_sig_cmd(L2CAP_CONF_REQ) and l2cap_bredr_sig_cmd(L2CAP_CONF_RSP) are calling l2cap_ertm_init(chan), and they call l2cap_chan_ready() (which clears CONF_NOT_COMPLETE flag) only when l2cap_ertm_init(chan) succeeded. l2cap_sock_init() does not call l2cap_ertm_init(chan), and it instead sets CONF_NOT_COMPLETE flag by calling l2cap_chan_set_defaults(). However, when connect() is requested, "command 0x0409 tx timeout" happens after 2 seconds from connect() request, and CONF_NOT_COMPLETE flag is cleared after 4 seconds from connect() request, for l2cap_conn_start() from l2cap_info_timeout() callback scheduled by schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT); in l2cap_connect() is calling l2cap_chan_ready(). Fix this problem by initializing delayed works used by L2CAP_MODE_ERTM mode as soon as l2cap_chan_create() allocates a channel, like I did in commit be8597239379f0f5 ("Bluetooth: initialize skb_queue_head at l2cap_chan_create()"). Link: https://syzkaller.appspot.com/bug?extid=83672956c7aa6af698b3 [1] Reported-by: syzbot <syzbot+83672956c7aa6af698b3@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2022-08-25Bluetooth: L2CAP: Fix build errors in some archsLuiz Augusto von Dentz
This attempts to fix the follow errors: In function 'memcmp', inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9, inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2003:15: ./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread] 44 | #define __underlying_memcmp __builtin_memcmp | ^ ./include/linux/fortify-string.h:420:16: note: in expansion of macro '__underlying_memcmp' 420 | return __underlying_memcmp(p, q, size); | ^~~~~~~~~~~~~~~~~~~ In function 'memcmp', inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9, inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2004:15: ./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread] 44 | #define __underlying_memcmp __builtin_memcmp | ^ ./include/linux/fortify-string.h:420:16: note: in expansion of macro '__underlying_memcmp' 420 | return __underlying_memcmp(p, q, size); | ^~~~~~~~~~~~~~~~~~~ Fixes: 332f1795ca20 ("Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2022-08-08Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regressionLuiz Augusto von Dentz
The patch d0be8347c623: "Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put" from Jul 21, 2022, leads to the following Smatch static checker warning: net/bluetooth/l2cap_core.c:1977 l2cap_global_chan_by_psm() error: we previously assumed 'c' could be null (see line 1996) Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2022-07-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-26Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_putLuiz Augusto von Dentz
This fixes the following trace which is caused by hci_rx_work starting up *after* the final channel reference has been put() during sock_close() but *before* the references to the channel have been destroyed, so instead the code now rely on kref_get_unless_zero/l2cap_chan_hold_unless_zero to prevent referencing a channel that is about to be destroyed. refcount_t: increment on 0; use-after-free. BUG: KASAN: use-after-free in refcount_dec_and_test+0x20/0xd0 Read of size 4 at addr ffffffc114f5bf18 by task kworker/u17:14/705 CPU: 4 PID: 705 Comm: kworker/u17:14 Tainted: G S W 4.14.234-00003-g1fb6d0bd49a4-dirty #28 Hardware name: Qualcomm Technologies, Inc. SM8150 V2 PM8150 Google Inc. MSM sm8150 Flame DVT (DT) Workqueue: hci0 hci_rx_work Call trace: dump_backtrace+0x0/0x378 show_stack+0x20/0x2c dump_stack+0x124/0x148 print_address_description+0x80/0x2e8 __kasan_report+0x168/0x188 kasan_report+0x10/0x18 __asan_load4+0x84/0x8c refcount_dec_and_test+0x20/0xd0 l2cap_chan_put+0x48/0x12c l2cap_recv_frame+0x4770/0x6550 l2cap_recv_acldata+0x44c/0x7a4 hci_acldata_packet+0x100/0x188 hci_rx_work+0x178/0x23c process_one_work+0x35c/0x95c worker_thread+0x4cc/0x960 kthread+0x1a8/0x1c4 ret_from_fork+0x10/0x18 Cc: stable@kernel.org Reported-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Tested-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>