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BUG: KASAN: use-after-free in d_inode include/linux/dcache.h:516 [inline]
BUG: KASAN: use-after-free in relay_switch_subbuf+0x8cc/0x940 kernel/relay.c:761
Read of size 8 at addr ffff88808e6f09f8 by task syz-executor.3/19377

CPU: 0 PID: 19377 Comm: syz-executor.3 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 d_inode include/linux/dcache.h:516 [inline]
 relay_switch_subbuf+0x8cc/0x940 kernel/relay.c:761
 relay_reserve include/linux/relay.h:261 [inline]
 trace_note+0x5eb/0x750 kernel/trace/blktrace.c:96
 trace_note_tsk kernel/trace/blktrace.c:127 [inline]
 __blk_add_trace+0xb86/0xe20 kernel/trace/blktrace.c:267
 blk_add_trace_plug+0xfe/0x240 kernel/trace/blktrace.c:1000
 trace_block_plug include/trace/events/block.h:456 [inline]
 blk_mq_make_request+0x14b7/0x1c00 block/blk-mq.c:1902
 generic_make_request+0x613/0xdf0 block/blk-core.c:2467
 submit_bio+0xb1/0x430 block/blk-core.c:2576
 submit_bio_wait+0x104/0x1b0 block/bio.c:930
 blkdev_issue_discard+0xdd/0x170 block/blk-lib.c:109
 sb_issue_discard include/linux/blkdev.h:1415 [inline]
 ext4_issue_discard fs/ext4/mballoc.c:2801 [inline]
 ext4_trim_extent fs/ext4/mballoc.c:5151 [inline]
 ext4_trim_all_free fs/ext4/mballoc.c:5210 [inline]
 ext4_trim_fs+0xf12/0x26c0 fs/ext4/mballoc.c:5316
 ext4_ioctl+0x6f1/0x3eb0 fs/ext4/ioctl.c:1057
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f00ac74a049
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f00ab0bf168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f00ac85cf60 RCX: 00007f00ac74a049
RDX: 00000000200000c0 RSI: 00000000c0185879 RDI: 0000000000000003
RBP: 00007f00ac7a408d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffb6c31a2f R14: 00007f00ab0bf300 R15: 0000000000022000

Allocated by task 4705:
 kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
 __d_alloc+0x2b/0xa10 fs/dcache.c:1612
 d_alloc+0x4a/0x230 fs/dcache.c:1696
 d_alloc_parallel+0xeb/0x19e0 fs/dcache.c:2443
 __lookup_slow+0x18d/0x4a0 fs/namei.c:1655
 lookup_slow fs/namei.c:1689 [inline]
 walk_component+0x7ac/0xda0 fs/namei.c:1811
 lookup_last fs/namei.c:2274 [inline]
 path_lookupat+0x1ff/0x8d0 fs/namei.c:2319
 filename_lookup+0x1ac/0x5a0 fs/namei.c:2349
 user_path_at include/linux/namei.h:57 [inline]
 do_faccessat+0x248/0x7a0 fs/open.c:397
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9:
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x7f/0x260 mm/slab.c:3765
 __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
 rcu_do_batch kernel/rcu/tree.c:2584 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
 rcu_process_callbacks+0x8ff/0x18b0 kernel/rcu/tree.c:2881
 __do_softirq+0x265/0x980 kernel/softirq.c:292

The buggy address belongs to the object at ffff88808e6f09a0
 which belongs to the cache dentry of size 288
The buggy address is located 88 bytes inside of
 288-byte region [ffff88808e6f09a0, ffff88808e6f0ac0)
The buggy address belongs to the page:
page:ffffea000239bc00 count:1 mapcount:0 mapping:ffff88813be45200 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002456e48 ffffea00010f09c8 ffff88813be45200
raw: 0000000000000000 ffff88808e6f0000 000000010000000b 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808e6f0880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808e6f0900: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88808e6f0980: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff88808e6f0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808e6f0a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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