diff options
| author | Huacai Chen <chenhuacai@loongson.cn> | 2025-01-29 20:06:52 +0800 |
|---|---|---|
| committer | Paul Moore <paul@paul-moore.com> | 2025-01-29 20:02:04 -0500 |
| commit | 35fcac7a7c25cc04f730b9570c737f31295fa92d (patch) | |
| tree | a4084bd28b2f14ec31fecdb42c9974b62ea4c565 /kernel/audit.c | |
| parent | 72deda0abee6e705ae71a93f69f55e33be5bca5c (diff) | |
audit: Initialize lsmctx to avoid memory allocation error
When audit is enabled in a kernel build, and there are no LSMs active
that support LSM labeling, it is possible that local variable lsmctx
in the AUDIT_SIGNAL_INFO handler in audit_receive_msg() could be used
before it is properly initialize. Then kmalloc() will try to allocate
a large amount of memory with the uninitialized length.
This patch corrects this problem by initializing the lsmctx to a safe
value when it is declared, which avoid errors like:
WARNING: CPU: 2 PID: 443 at mm/page_alloc.c:4727 __alloc_pages_noprof
...
ra: 9000000003059644 ___kmalloc_large_node+0x84/0x1e0
ERA: 900000000304d588 __alloc_pages_noprof+0x4c8/0x1040
CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
PRMD: 00000004 (PPLV0 +PIE -PWE)
EUEN: 00000007 (+FPE +SXE +ASXE -BTE)
ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7)
ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0)
PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
CPU: 2 UID: 0 PID: 443 Comm: auditd Not tainted 6.13.0-rc1+ #1899
...
Call Trace:
[<9000000002def6a8>] show_stack+0x30/0x148
[<9000000002debf58>] dump_stack_lvl+0x68/0xa0
[<9000000002e0fe18>] __warn+0x80/0x108
[<900000000407486c>] report_bug+0x154/0x268
[<90000000040ad468>] do_bp+0x2a8/0x320
[<9000000002dedda0>] handle_bp+0x120/0x1c0
[<900000000304d588>] __alloc_pages_noprof+0x4c8/0x1040
[<9000000003059640>] ___kmalloc_large_node+0x80/0x1e0
[<9000000003061504>] __kmalloc_noprof+0x2c4/0x380
[<9000000002f0f7ac>] audit_receive_msg+0x764/0x1530
[<9000000002f1065c>] audit_receive+0xe4/0x1c0
[<9000000003e5abe8>] netlink_unicast+0x340/0x450
[<9000000003e5ae9c>] netlink_sendmsg+0x1a4/0x4a0
[<9000000003d9ffd0>] __sock_sendmsg+0x48/0x58
[<9000000003da32f0>] __sys_sendto+0x100/0x170
[<9000000003da3374>] sys_sendto+0x14/0x28
[<90000000040ad574>] do_syscall+0x94/0x138
[<9000000002ded318>] handle_syscall+0xb8/0x158
Fixes: 6fba89813ccf333d ("lsm: ensure the correct LSM context releaser")
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
[PM: resolved excessive line length in the backtrace]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Diffstat (limited to 'kernel/audit.c')
| -rw-r--r-- | kernel/audit.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index 13d0144efaa3..5f5bf85bcc90 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1221,7 +1221,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh, struct audit_buffer *ab; u16 msg_type = nlh->nlmsg_type; struct audit_sig_info *sig_data; - struct lsm_context lsmctx; + struct lsm_context lsmctx = { NULL, 0, 0 }; err = audit_netlink_ok(skb, msg_type); if (err) |