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| author |   Carlos Llamas <cmllamas@google.com> | 2025-05-24 22:07:58 +0000 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-10 07:17:10 -0400 |
| commit | 72a726fb5f25fbb31d6060acfb671c1955831245 (patch) | |
| tree | 826819c4b33ef47593bef62a6c8fffdbf4a89263 | |
| parent | binder: fix use-after-free in binderfs_evict_inode() (diff) | |
| download | laptop-kernel-72a726fb5f25fbb31d6060acfb671c1955831245.tar.xz laptop-kernel-72a726fb5f25fbb31d6060acfb671c1955831245.zip | |
binder: fix yet another UAF in binder_devices
commit 9857af0fcff385c75433f2162c30c62eb912ef6d upstream.
Commit e77aff5528a18 ("binderfs: fix use-after-free in binder_devices")
addressed a use-after-free where devices could be released without first
being removed from the binder_devices list. However, there is a similar
path in binder_free_proc() that was missed:
==================================================================
BUG: KASAN: slab-use-after-free in binder_remove_device+0xd4/0x100
Write of size 8 at addr ffff0000c773b900 by task umount/467
CPU: 12 UID: 0 PID: 467 Comm: umount Not tainted 6.15.0-rc7-00138-g57483a362741 #9 PREEMPT
Hardware name: linux,dummy-virt (DT)
Call trace:
binder_remove_device+0xd4/0x100
binderfs_evict_inode+0x230/0x2f0
evict+0x25c/0x5dc
iput+0x304/0x480
dentry_unlink_inode+0x208/0x46c
__dentry_kill+0x154/0x530
[...]
Allocated by task 463:
__kmalloc_cache_noprof+0x13c/0x324
binderfs_binder_device_create.isra.0+0x138/0xa60
binder_ctl_ioctl+0x1ac/0x230
[...]
Freed by task 215:
kfree+0x184/0x31c
binder_proc_dec_tmpref+0x33c/0x4ac
binder_deferred_func+0xc10/0x1108
process_one_work+0x520/0xba4
[...]
==================================================================
Call binder_remove_device() within binder_free_proc() to ensure the
device is removed from the binder_devices list before being kfreed.
Cc: stable@vger.kernel.org
Fixes: 12d909cac1e1 ("binderfs: add new binder devices to binder_devices")
Reported-by: syzbot+4af454407ec393de51d6@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4af454407ec393de51d6
Tested-by: syzbot+4af454407ec393de51d6@syzkaller.appspotmail.com
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20250524220758.915028-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/android/binder.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 8d9c5f436fca..6be0f7ac7213 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5246,6 +5246,7 @@ static void binder_free_proc(struct binder_proc *proc) __func__, proc->outstanding_txns); device = container_of(proc->context, struct binder_device, context); if (refcount_dec_and_test(&device->ref)) { + binder_remove_device(device); kfree(proc->context->name); kfree(device); } |