syzbot

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BUG: KASAN: use-after-free in __lock_acquire+0x2eff/0x3640 kernel/locking/lockdep.c:3224
Read of size 8 at addr ffff8801bbeb6fb8 by task syzkaller896894/3818

CPU: 1 PID: 3818 Comm: syzkaller896894 Not tainted 4.9.80-gb30d2b5 #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801b28bf8e0 ffffffff81d94b69 ffffea0006efad80 ffff8801bbeb6fb8
 0000000000000000 ffff8801bbeb6fb8 ffff8801bbeb6fb8 ffff8801b28bf918
 ffffffff8153e093 ffff8801bbeb6fb8 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81d94b69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d94b69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8153e093>] print_address_description+0x73/0x280 mm/kasan/report.c:252
 [<ffffffff8153e5b5>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8153e5b5>] kasan_report+0x275/0x360 mm/kasan/report.c:408
 [<ffffffff8153e714>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff8123ed7f>] __lock_acquire+0x2eff/0x3640 kernel/locking/lockdep.c:3224
 [<ffffffff8123fefe>] lock_acquire+0x12e/0x410 kernel/locking/lockdep.c:3756
 [<ffffffff838b32ae>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline]
 [<ffffffff838b32ae>] _raw_spin_lock_irqsave+0x4e/0x70 kernel/locking/spinlock.c:159
 [<ffffffff81224464>] remove_wait_queue+0x14/0x40 kernel/sched/wait.c:49
 [<ffffffff8165142f>] ep_remove_wait_queue fs/eventpoll.c:535 [inline]
 [<ffffffff8165142f>] ep_unregister_pollwait.isra.6+0xaf/0x240 fs/eventpoll.c:553
 [<ffffffff81652176>] ep_free+0x96/0x1b0 fs/eventpoll.c:770
 [<ffffffff816522d4>] ep_eventpoll_release+0x44/0x60 fs/eventpoll.c:802
 [<ffffffff8157568c>] __fput+0x28c/0x6e0 fs/file_table.c:208
 [<ffffffff81575b65>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff811957d5>] task_work_run+0x115/0x190 kernel/task_work.c:116
 [<ffffffff8113c277>] exit_task_work include/linux/task_work.h:21 [inline]
 [<ffffffff8113c277>] do_exit+0x7e7/0x2a40 kernel/exit.c:833
 [<ffffffff81142988>] do_group_exit+0x108/0x320 kernel/exit.c:937
 [<ffffffff81142bbd>] SYSC_exit_group kernel/exit.c:948 [inline]
 [<ffffffff81142bbd>] SyS_exit_group+0x1d/0x20 kernel/exit.c:946
 [<ffffffff838b346e>] entry_SYSCALL_64_fastpath+0x29/0xe8

Allocated by task 3818:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:609
 kmem_cache_alloc_trace+0xfb/0x2a0 mm/slub.c:2742
 kmalloc include/linux/slab.h:490 [inline]
 kzalloc include/linux/slab.h:636 [inline]
 binder_get_thread+0x15d/0x750 drivers/android/binder.c:4451
 binder_poll+0x4a/0x210 drivers/android/binder.c:4554
 ep_item_poll fs/eventpoll.c:811 [inline]
 ep_insert fs/eventpoll.c:1347 [inline]
 SYSC_epoll_ctl fs/eventpoll.c:1975 [inline]
 SyS_epoll_ctl+0x11d7/0x2190 fs/eventpoll.c:1861
 entry_SYSCALL_64_fastpath+0x29/0xe8

Freed by task 3818:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57
 save_stack+0x43/0xd0 mm/kasan/kasan.c:505
 set_track mm/kasan/kasan.c:517 [inline]
 kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582
 slab_free_hook mm/slub.c:1355 [inline]
 slab_free_freelist_hook mm/slub.c:1377 [inline]
 slab_free mm/slub.c:2958 [inline]
 kfree+0x103/0x300 mm/slub.c:3878
 binder_free_thread drivers/android/binder.c:4479 [inline]
 binder_thread_dec_tmpref+0x1cc/0x240 drivers/android/binder.c:2035
 binder_thread_release+0x27d/0x540 drivers/android/binder.c:4543
 binder_ioctl+0x9c0/0x11b0 drivers/android/binder.c:4759
 vfs_ioctl fs/ioctl.c:43 [inline]
 do_vfs_ioctl+0x1aa/0x1140 fs/ioctl.c:679
 SYSC_ioctl fs/ioctl.c:694 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 entry_SYSCALL_64_fastpath+0x29/0xe8

The buggy address belongs to the object at ffff8801bbeb6f00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 184 bytes inside of
 512-byte region [ffff8801bbeb6f00, ffff8801bbeb7100)
The buggy address belongs to the page:
page:ffffea0006efad80 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x8000000000004080(slab|head)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801bbeb6e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801bbeb6f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801bbeb6f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff8801bbeb7000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801bbeb7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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