================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x96/0x1bc0 kernel/locking/lockdep.c:3827 Read of size 8 at addr ffff888092f35a78 by task syz-executor.5/12096 CPU: 0 PID: 12096 Comm: syz-executor.5 Not tainted 5.6.0-rc6-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+0x1e9/0x30e lib/dump_stack.c:118 print_address_description+0x74/0x5c0 mm/kasan/report.c:374 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506 kasan_report+0x25/0x50 mm/kasan/common.c:641 __lock_acquire+0x96/0x1bc0 kernel/locking/lockdep.c:3827 lock_acquire+0x154/0x250 kernel/locking/lockdep.c:4484 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] lockref_get+0x11/0x50 lib/lockref.c:52 dget include/linux/dcache.h:321 [inline] simple_recursive_removal+0x31/0x6e0 fs/libfs.c:268 debugfs_remove+0x45/0x60 fs/debugfs/inode.c:713 blk_trace_free kernel/trace/blktrace.c:311 [inline] do_blk_trace_setup+0x796/0x9b0 kernel/trace/blktrace.c:557 __blk_trace_setup kernel/trace/blktrace.c:571 [inline] blk_trace_ioctl+0x24c/0x7d0 kernel/trace/blktrace.c:712 blkdev_ioctl+0x101/0x5c0 block/ioctl.c:710 block_ioctl+0xb6/0xf0 fs/block_dev.c:1983 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c849 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f080b6dcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f080b6dd6d4 RCX: 000000000045c849 RDX: 0000000020000080 RSI: 00000000c0481273 RDI: 0000000000000008 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000228 R14: 00000000004c44eb R15: 000000000076bf0c Allocated by task 12096: save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc+0x118/0x1c0 mm/kasan/common.c:515 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x1f5/0x2d0 mm/slab.c:3484 __d_alloc+0x2a/0x6d0 fs/dcache.c:1690 d_alloc fs/dcache.c:1769 [inline] d_alloc_parallel+0x81/0x13b0 fs/dcache.c:2521 __lookup_slow+0xaa/0x370 fs/namei.c:1742 lookup_one_len+0x10e/0x200 fs/namei.c:2661 start_creating+0x10f/0x2c0 fs/debugfs/inode.c:338 __debugfs_create_file+0x74/0x470 fs/debugfs/inode.c:383 do_blk_trace_setup+0x3d6/0x9b0 kernel/trace/blktrace.c:524 __blk_trace_setup kernel/trace/blktrace.c:571 [inline] blk_trace_ioctl+0x24c/0x7d0 kernel/trace/blktrace.c:712 blkdev_ioctl+0x101/0x5c0 block/ioctl.c:710 block_ioctl+0xb6/0xf0 fs/block_dev.c:1983 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12090: save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x12e/0x1e0 mm/kasan/common.c:476 __cache_free mm/slab.c:3426 [inline] kmem_cache_free+0x7e/0xf0 mm/slab.c:3694 rcu_do_batch kernel/rcu/tree.c:2186 [inline] rcu_core+0x7e4/0x1080 kernel/rcu/tree.c:2410 __do_softirq+0x268/0x7c5 kernel/softirq.c:292 The buggy address belongs to the object at ffff888092f359e0 which belongs to the cache dentry(87:syz5) of size 288 The buggy address is located 152 bytes inside of 288-byte region [ffff888092f359e0, ffff888092f35b00) The buggy address belongs to the page: page:ffffea00024bcd40 refcount:1 mapcount:0 mapping:ffff88808a8e9e00 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00025a6ec8 ffffea00022fd748 ffff88808a8e9e00 raw: 0000000000000000 ffff888092f35040 000000010000000b 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888092f35900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888092f35980: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb >ffff888092f35a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888092f35a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888092f35b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================