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BUG: KASAN: use-after-free in do_blk_trace_setup+0xa8f/0xb10 kernel/trace/blktrace.c:561
Read of size 8 at addr ffff888090a401c0 by task syz-executor.4/17062

CPU: 1 PID: 17062 Comm: syz-executor.4 Not tainted 4.14.111 #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xaf/0x2b5 mm/kasan/report.c:393
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 do_blk_trace_setup+0xa8f/0xb10 kernel/trace/blktrace.c:561
 blk_trace_setup+0xbd/0x140 kernel/trace/blktrace.c:579
 sg_ioctl+0x31b/0x27e0 drivers/scsi/sg.c:1127
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4582f9
RSP: 002b:00007fde75e43c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004582f9
RDX: 0000000020000000 RSI: 00000000c0481273 RDI: 0000000000000009
RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fde75e446d4
R13: 00000000004bf702 R14: 00000000004d1548 R15: 00000000ffffffff

Allocated by task 17062:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 do_blk_trace_setup+0x120/0xb10 kernel/trace/blktrace.c:495
 blk_trace_setup+0xbd/0x140 kernel/trace/blktrace.c:579
 sg_ioctl+0x31b/0x27e0 drivers/scsi/sg.c:1127
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 17067:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcc/0x270 mm/slab.c:3815
 blk_trace_free+0x106/0x140 kernel/trace/blktrace.c:330
 blk_trace_cleanup kernel/trace/blktrace.c:351 [inline]
 blk_trace_remove+0x59/0x80 kernel/trace/blktrace.c:364
 sg_ioctl+0x247/0x27e0 drivers/scsi/sg.c:1136
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff888090a40180
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 64 bytes inside of
 128-byte region [ffff888090a40180, ffff888090a40200)
The buggy address belongs to the page:
page:ffffea0002429000 count:1 mapcount:0 mapping:ffff888090a40000 index:0x0
flags: 0x1fffc0000000100(slab)
raw: 01fffc0000000100 ffff888090a40000 0000000000000000 0000000100000015
raw: ffffea00021f47a0 ffffea0002538420 ffff8880aa800640 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888090a40080: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff888090a40100: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff888090a40180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888090a40200: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff888090a40280: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
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hid-generic 0000:0000:0000.0012: unknown main item tag 0x7