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| author | Carlos Llamas <cmllamas@google.com> | 2024-09-26 23:36:14 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-10-13 17:12:21 +0200 |
| commit | 7e20434cbca814cb91a0a261ca0106815ef48e5f (patch) | |
| tree | 4db79148f113ba1b91bcfb015cd8a14bd731fec5 /drivers/android/binder.c | |
| parent | 011e69a1b23011c0db3af4b8293fdd4522cc97b0 (diff) | |
| download | lwn-7e20434cbca814cb91a0a261ca0106815ef48e5f.tar.gz lwn-7e20434cbca814cb91a0a261ca0106815ef48e5f.zip | |
binder: fix freeze UAF in binder_release_work()
When a binder reference is cleaned up, any freeze work queued in the
associated process should also be removed. Otherwise, the reference is
freed while its ref->freeze.work is still queued in proc->work leading
to a use-after-free issue as shown by the following KASAN report:
==================================================================
BUG: KASAN: slab-use-after-free in binder_release_work+0x398/0x3d0
Read of size 8 at addr ffff31600ee91488 by task kworker/5:1/211
CPU: 5 UID: 0 PID: 211 Comm: kworker/5:1 Not tainted 6.11.0-rc7-00382-gfc6c92196396 #22
Hardware name: linux,dummy-virt (DT)
Workqueue: events binder_deferred_func
Call trace:
binder_release_work+0x398/0x3d0
binder_deferred_func+0xb60/0x109c
process_one_work+0x51c/0xbd4
worker_thread+0x608/0xee8
Allocated by task 703:
__kmalloc_cache_noprof+0x130/0x280
binder_thread_write+0xdb4/0x42a0
binder_ioctl+0x18f0/0x25ac
__arm64_sys_ioctl+0x124/0x190
invoke_syscall+0x6c/0x254
Freed by task 211:
kfree+0xc4/0x230
binder_deferred_func+0xae8/0x109c
process_one_work+0x51c/0xbd4
worker_thread+0x608/0xee8
==================================================================
This commit fixes the issue by ensuring any queued freeze work is removed
when cleaning up a binder reference.
Fixes: d579b04a52a1 ("binder: frozen notification")
Cc: stable@vger.kernel.org
Acked-by: Todd Kjos <tkjos@android.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20240926233632.821189-4-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/android/binder.c')
| -rw-r--r-- | drivers/android/binder.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 8bca2de6fa24..d955135ee37a 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -1225,6 +1225,12 @@ static void binder_cleanup_ref_olocked(struct binder_ref *ref) binder_dequeue_work(ref->proc, &ref->death->work); binder_stats_deleted(BINDER_STAT_DEATH); } + + if (ref->freeze) { + binder_dequeue_work(ref->proc, &ref->freeze->work); + binder_stats_deleted(BINDER_STAT_FREEZE); + } + binder_stats_deleted(BINDER_STAT_REF); } |