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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 ffff8801d8c47a78 by task syz-executor2/9802

CPU: 0 PID: 9802 Comm: syz-executor2 Not tainted 4.9.71-g319c8e1 #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d23d77e0 ffffffff81d91639 ffffea00076311c0 ffff8801d8c47a78
 0000000000000000 ffff8801d8c47a78 ffff8801d8c47a78 ffff8801d23d7818
 ffffffff8153af43 ffff8801d8c47a78 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81d91639>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d91639>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8153af43>] print_address_description+0x73/0x280 mm/kasan/report.c:252
 [<ffffffff8153b465>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8153b465>] kasan_report+0x275/0x360 mm/kasan/report.c:408
 [<ffffffff8153b5c4>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff8123cb6f>] __lock_acquire+0x2eff/0x3640 kernel/locking/lockdep.c:3224
 [<ffffffff8123dcee>] lock_acquire+0x12e/0x410 kernel/locking/lockdep.c:3756
 [<ffffffff838ab42e>] __raw_write_lock_irqsave include/linux/rwlock_api_smp.h:186 [inline]
 [<ffffffff838ab42e>] _raw_write_lock_irqsave+0x4e/0x62 kernel/locking/spinlock.c:303
 [<ffffffff82660630>] sg_remove_request+0x70/0x120 drivers/scsi/sg.c:2122
 [<ffffffff82660c45>] sg_finish_rem_req+0x295/0x340 drivers/scsi/sg.c:1838
 [<ffffffff82662a7c>] sg_read+0xa1c/0x1440 drivers/scsi/sg.c:527
 [<ffffffff81568d93>] __vfs_read+0x103/0x670 fs/read_write.c:452
 [<ffffffff8156cb2e>] vfs_read+0x11e/0x380 fs/read_write.c:475
 [<ffffffff81570859>] SYSC_read fs/read_write.c:591 [inline]
 [<ffffffff81570859>] SyS_read+0xd9/0x1b0 fs/read_write.c:584
 [<ffffffff81006fc7>] do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline]
 [<ffffffff81006fc7>] do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384
 [<ffffffff838acb61>] entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124

Allocated by task 9802:
 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
 setfl fs/fcntl.c:70 [inline]
 do_fcntl fs/fcntl.c:267 [inline]
 SYSC_fcntl fs/fcntl.c:372 [inline]
 SyS_fcntl+0x658/0xc70 fs/fcntl.c:357
 C_SYSC_fcntl64 fs/compat.c:469 [inline]
 compat_SyS_fcntl64+0xce/0x4f0 fs/compat.c:403
 do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline]
 do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384
 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:124

Freed by task 0:
 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+0xb2/0x2e0 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+0x871/0x12c0 kernel/rcu/tree.c:3037
 __do_softirq+0x206/0x951 kernel/softirq.c:284

The buggy address belongs to the object at ffff8801d8c47a00
 which belongs to the cache fasync_cache of size 96
The buggy address is located 24 bytes to the right of
 96-byte region [ffff8801d8c47a00, ffff8801d8c47a60)
The buggy address belongs to the page:
page:ffffea00076311c0 count:1 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000080(slab)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d8c47900: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8801d8c47980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff8801d8c47a00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
                                                                ^
 ffff8801d8c47a80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff8801d8c47b00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
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