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authorCarlos Llamas <cmllamas@google.com>2025-01-30 21:58:22 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-02-20 15:20:11 +0100
commite77aff5528a183462714f750e45add6cc71e276a (patch)
tree3fa242a8d863facd0a03d15350b4a407c5c7df20
parentdcb0d43ba8eb9517e70b1a0e4b0ae0ab657a0e5a (diff)
binderfs: fix use-after-free in binder_devices
Devices created through binderfs are added to the global binder_devices list but are not removed before being destroyed. This leads to dangling pointers in the list and subsequent use-after-free errors: ================================================================== BUG: KASAN: slab-use-after-free in binder_add_device+0x5c/0x9c Write of size 8 at addr ffff0000c258d708 by task mount/653 CPU: 7 UID: 0 PID: 653 Comm: mount Not tainted 6.13.0-09030-g6d61a53dd6f5 #1 Hardware name: linux,dummy-virt (DT) Call trace: binder_add_device+0x5c/0x9c binderfs_binder_device_create+0x690/0x84c [...] __arm64_sys_mount+0x324/0x3bc Allocated by task 632: binderfs_binder_device_create+0x168/0x84c binder_ctl_ioctl+0xfc/0x184 [...] __arm64_sys_ioctl+0x110/0x150 Freed by task 649: kfree+0xe0/0x338 binderfs_evict_inode+0x138/0x1dc [...] ================================================================== Remove devices from binder_devices before destroying them. Cc: Li Li <dualli@google.com> Reported-by: syzbot+7015dcf45953112c8b45@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7015dcf45953112c8b45 Fixes: 12d909cac1e1 ("binderfs: add new binder devices to binder_devices") Signed-off-by: Carlos Llamas <cmllamas@google.com> Tested-by: syzbot+7015dcf45953112c8b45@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20250130215823.1518990-1-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/android/binderfs.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
index bc6bae76ccaf..94c6446604fc 100644
--- a/drivers/android/binderfs.c
+++ b/drivers/android/binderfs.c
@@ -274,6 +274,7 @@ static void binderfs_evict_inode(struct inode *inode)
mutex_unlock(&binderfs_minors_mutex);
if (refcount_dec_and_test(&device->ref)) {
+ hlist_del_init(&device->hlist);
kfree(device->context.name);
kfree(device);
}