linux/drivers/android
Carlos Llamas 1aa3aaf895 binder: fix memory leaks of spam and pending work
A transaction complete work is allocated and queued for each
transaction. Under certain conditions the work->type might be marked as
BINDER_WORK_TRANSACTION_ONEWAY_SPAM_SUSPECT to notify userspace about
potential spamming threads or as BINDER_WORK_TRANSACTION_PENDING when
the target is currently frozen.

However, these work types are not being handled in binder_release_work()
so they will leak during a cleanup. This was reported by syzkaller with
the following kmemleak dump:

BUG: memory leak
unreferenced object 0xffff88810e2d6de0 (size 32):
  comm "syz-executor338", pid 5046, jiffies 4294968230 (age 13.590s)
  hex dump (first 32 bytes):
    e0 6d 2d 0e 81 88 ff ff e0 6d 2d 0e 81 88 ff ff  .m-......m-.....
    04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81573b75>] kmalloc_trace+0x25/0x90 mm/slab_common.c:1114
    [<ffffffff83d41873>] kmalloc include/linux/slab.h:599 [inline]
    [<ffffffff83d41873>] kzalloc include/linux/slab.h:720 [inline]
    [<ffffffff83d41873>] binder_transaction+0x573/0x4050 drivers/android/binder.c:3152
    [<ffffffff83d45a05>] binder_thread_write+0x6b5/0x1860 drivers/android/binder.c:4010
    [<ffffffff83d486dc>] binder_ioctl_write_read drivers/android/binder.c:5066 [inline]
    [<ffffffff83d486dc>] binder_ioctl+0x1b2c/0x3cf0 drivers/android/binder.c:5352
    [<ffffffff816b25f2>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff816b25f2>] __do_sys_ioctl fs/ioctl.c:871 [inline]
    [<ffffffff816b25f2>] __se_sys_ioctl fs/ioctl.c:857 [inline]
    [<ffffffff816b25f2>] __x64_sys_ioctl+0xf2/0x140 fs/ioctl.c:857
    [<ffffffff84b30008>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff84b30008>] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fix the leaks by kfreeing these work types in binder_release_work() and
handle them as a BINDER_WORK_TRANSACTION_COMPLETE cleanup.

Cc: stable@vger.kernel.org
Fixes: 0567461a7a ("binder: return pending info for frozen async txns")
Fixes: a7dc1e6f99 ("binder: tell userspace to dump current backtrace when detected oneway spamming")
Reported-by: syzbot+7f10c1653e35933c0f1e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7f10c1653e35933c0f1e
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Todd Kjos <tkjos@google.com>
Link: https://lore.kernel.org/r/20230922175138.230331-1-cmllamas@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-05 12:48:08 +02:00
..
binder_alloc_selftest.c Revert "android: binder: stop saving a pointer to the VMA" 2023-05-13 20:30:16 +09:00
binder_alloc.c binder: fix memory leak in binder_init() 2023-08-04 15:25:01 +02:00
binder_alloc.h binder: fix memory leak in binder_init() 2023-08-04 15:25:01 +02:00
binder_internal.h Binder: Add async from to transaction record 2023-05-13 20:38:12 +09:00
binder_trace.h Binder: add TF_UPDATE_TXN to replace outdated txn 2022-06-27 16:16:30 +02:00
binder.c binder: fix memory leaks of spam and pending work 2023-10-05 12:48:08 +02:00
binderfs.c Char/Misc driver changes for 6.6-rc1 2023-09-01 09:53:54 -07:00
Kconfig remove CONFIG_ANDROID 2022-07-01 10:41:09 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00