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BUG: KASAN: slab-out-of-bounds in __lock_acquire+0x2eff/0x3640 kernel/locking/lockdep.c:3224
Read of size 8 at addr ffff8801ce02b878 by task syz-executor3/21535

CPU: 0 PID: 21535 Comm: syz-executor3 Not tainted 4.9.77-ge12a9c4 #18
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801b3f8f740 ffffffff81d941c9 ffffea0007380ac0 ffff8801ce02b878
 0000000000000000 ffff8801ce02b878 ffff8801ce02b878 ffff8801b3f8f778
 ffffffff8153db93 ffff8801ce02b878 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81d941c9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d941c9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8153db93>] print_address_description+0x73/0x280 mm/kasan/report.c:252
 [<ffffffff8153e0b5>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8153e0b5>] kasan_report+0x275/0x360 mm/kasan/report.c:408
 [<ffffffff8153e214>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff8123ec9f>] __lock_acquire+0x2eff/0x3640 kernel/locking/lockdep.c:3224
 [<ffffffff8123fe1e>] lock_acquire+0x12e/0x410 kernel/locking/lockdep.c:3756
 [<ffffffff838b2b4e>] __raw_write_lock_irqsave include/linux/rwlock_api_smp.h:186 [inline]
 [<ffffffff838b2b4e>] _raw_write_lock_irqsave+0x4e/0x62 kernel/locking/spinlock.c:303
 [<ffffffff826672d0>] sg_remove_request+0x70/0x120 drivers/scsi/sg.c:2122
 [<ffffffff826678e5>] sg_finish_rem_req+0x295/0x340 drivers/scsi/sg.c:1838
 [<ffffffff8266971c>] sg_read+0xa1c/0x1440 drivers/scsi/sg.c:527
 [<ffffffff8156c5c1>] do_loop_readv_writev.part.17+0x141/0x1e0 fs/read_write.c:714
 [<ffffffff81570430>] do_loop_readv_writev fs/read_write.c:880 [inline]
 [<ffffffff81570430>] do_readv_writev+0x520/0x750 fs/read_write.c:874
 [<ffffffff815706e4>] vfs_readv+0x84/0xc0 fs/read_write.c:898
 [<ffffffff81570806>] do_readv+0xe6/0x250 fs/read_write.c:924
 [<ffffffff81573cf7>] SYSC_readv fs/read_write.c:1011 [inline]
 [<ffffffff81573cf7>] SyS_readv+0x27/0x30 fs/read_write.c:1008
 [<ffffffff838b2c2e>] entry_SYSCALL_64_fastpath+0x29/0xe8

Allocated by task 21535:
 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
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547
 slab_post_alloc_hook mm/slab.h:417 [inline]
 slab_alloc_node mm/slub.c:2715 [inline]
 slab_alloc mm/slub.c:2723 [inline]
 kmem_cache_alloc+0xba/0x290 mm/slub.c:2728
 fasync_alloc fs/fcntl.c:604 [inline]
 fasync_add_entry fs/fcntl.c:662 [inline]
 fasync_helper+0x37/0xb0 fs/fcntl.c:691
 sg_fasync+0x86/0xb0 drivers/scsi/sg.c:1203
 ioctl_fioasync fs/ioctl.c:534 [inline]
 do_vfs_ioctl+0x2d8/0x1140 fs/ioctl.c:639
 SYSC_ioctl fs/ioctl.c:694 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 entry_SYSCALL_64_fastpath+0x29/0xe8

Freed by task 8403:
 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]
 kmem_cache_free+0xc7/0x300 mm/slub.c:2980
 fasync_free_rcu+0x1d/0x20 fs/fcntl.c:563
 __rcu_reclaim kernel/rcu/rcu.h:118 [inline]
 rcu_do_batch kernel/rcu/tree.c:2789 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline]
 rcu_process_callbacks+0x898/0x1300 kernel/rcu/tree.c:3037
 __do_softirq+0x206/0x951 kernel/softirq.c:284

The buggy address belongs to the object at ffff8801ce02b800
 which belongs to the cache fasync_cache of size 96
The buggy address is located 24 bytes to the right of
 96-byte region [ffff8801ce02b800, ffff8801ce02b860)
The buggy address belongs to the page:
page:ffffea0007380ac0 count:1 mapcount:0 mapping:          (null) index:0xffff8801ce02b600
flags: 0x8000000000000080(slab)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ce02b700: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8801ce02b780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff8801ce02b800: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
                                                                ^
 ffff8801ce02b880: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8801ce02b900: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
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