================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3fa6/0x4c50 kernel/locking/lockdep.c:4225 Read of size 8 at addr ffff888089dd30a0 by task syz-executor.4/8575 CPU: 0 PID: 8575 Comm: syz-executor.4 Not tainted 5.7.0-rc2-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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511 kasan_report+0x33/0x50 mm/kasan/common.c:625 __lock_acquire+0x3fa6/0x4c50 kernel/locking/lockdep.c:4225 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 lockref_get+0x11/0x50 include/linux/spinlock.h:353 dget include/linux/dcache.h:321 [inline] simple_recursive_removal+0x43/0x730 fs/libfs.c:268 debugfs_remove fs/debugfs/inode.c:703 [inline] debugfs_remove+0x59/0x80 fs/debugfs/inode.c:697 blk_trace_free+0x31/0x130 kernel/trace/blktrace.c:311 do_blk_trace_setup+0x711/0xb30 kernel/trace/blktrace.c:557 __blk_trace_setup+0xca/0x180 kernel/trace/blktrace.c:571 blk_trace_ioctl+0x162/0x2b0 kernel/trace/blktrace.c:712 blkdev_ioctl+0xbe/0x660 block/ioctl.c:711 block_ioctl+0xf9/0x140 fs/block_dev.c:2005 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f447fecec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e1540 RCX: 000000000045c829 RDX: 0000000020000080 RSI: 00000000c0481273 RDI: 0000000000000008 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000022a R14: 00000000004c4506 R15: 00007f447fecf6d4 Allocated by task 8575: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468 slab_post_alloc_hook mm/slab.h:586 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x11b/0x740 mm/slab.c:3484 __d_alloc+0x2b/0x8e0 fs/dcache.c:1690 d_alloc+0x4a/0x240 fs/dcache.c:1769 d_alloc_parallel+0xe8/0x1b10 fs/dcache.c:2521 __lookup_slow+0x193/0x490 fs/namei.c:1515 lookup_one_len+0x163/0x190 fs/namei.c:2548 start_creating+0x12b/0x250 fs/debugfs/inode.c:338 __debugfs_create_file+0x62/0x400 fs/debugfs/inode.c:383 do_blk_trace_setup+0x351/0xb30 kernel/trace/blktrace.c:524 __blk_trace_setup+0xca/0x180 kernel/trace/blktrace.c:571 blk_trace_ioctl+0x162/0x2b0 kernel/trace/blktrace.c:712 blkdev_ioctl+0xbe/0x660 block/ioctl.c:711 block_ioctl+0xf9/0x140 fs/block_dev.c:2005 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 126: save_stack+0x1b/0x40 mm/kasan/common.c:49 set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456 __cache_free mm/slab.c:3426 [inline] kmem_cache_free+0x7f/0x320 mm/slab.c:3694 rcu_do_batch kernel/rcu/tree.c:2206 [inline] rcu_core+0x59f/0x1370 kernel/rcu/tree.c:2433 __do_softirq+0x26c/0x9f7 kernel/softirq.c:292 The buggy address belongs to the object at ffff888089dd3000 which belongs to the cache dentry of size 304 The buggy address is located 160 bytes inside of 304-byte region [ffff888089dd3000, ffff888089dd3130) The buggy address belongs to the page: page:ffffea00022774c0 refcount:1 mapcount:0 mapping:0000000027272d18 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002277448 ffffea0002272b88 ffff88821bc50540 raw: 0000000000000000 ffff888089dd3000 000000010000000b 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888089dd2f80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888089dd3000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888089dd3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888089dd3100: fb fb fb fb fb fb fc fc fc fc fc fc fc fc 00 00 ffff888089dd3180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================