devpts: called with bogus options devpts: called with bogus options devpts: called with bogus options devpts: called with bogus options ================================================================== BUG: KASAN: use-after-free in debugfs_remove+0xd3/0xf0 fs/debugfs/inode.c:687 Read of size 8 at addr ffff88806afc55c0 by task kworker/0:0/7206 CPU: 0 PID: 7206 Comm: kworker/0:0 Not tainted 4.19.95-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events __blk_release_queue Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x123/0x177 lib/dump_stack.c:118 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 debugfs_remove+0xd3/0xf0 fs/debugfs/inode.c:687 blk_trace_free+0x30/0x130 kernel/trace/blktrace.c:312 blk_trace_cleanup kernel/trace/blktrace.c:339 [inline] __blk_trace_remove+0x57/0x80 kernel/trace/blktrace.c:352 blk_trace_shutdown+0x54/0x70 kernel/trace/blktrace.c:752 __blk_release_queue+0x1f7/0x490 block/blk-sysfs.c:855 process_one_work+0x830/0x1670 kernel/workqueue.c:2153 worker_thread+0x85/0xb60 kernel/workqueue.c:2296 kthread+0x324/0x3e0 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Allocated by task 17353: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kobject: 'holders' (000000009dcb38d6): kobject_add_internal: parent: 'loop0', set: '' kmem_cache_alloc+0x12e/0x730 mm/slab.c:3559 __d_alloc+0x28/0x9d0 fs/dcache.c:1610 d_alloc+0x42/0x220 fs/dcache.c:1694 d_alloc_parallel+0xf3/0x1750 fs/dcache.c:2441 __lookup_slow+0x18d/0x400 fs/namei.c:1654 lookup_one_len+0x132/0x160 fs/namei.c:2543 kobject: 'slaves' (00000000db644afc): kobject_add_internal: parent: 'loop0', set: '' start_creating+0x91/0x190 fs/debugfs/inode.c:313 __debugfs_create_file+0x37/0x390 fs/debugfs/inode.c:352 debugfs_create_file+0x24/0x30 fs/debugfs/inode.c:404 do_blk_trace_setup+0x31e/0xa70 kernel/trace/blktrace.c:528 __blk_trace_setup+0xb4/0x130 kernel/trace/blktrace.c:577 blk_trace_ioctl+0x155/0x2a0 kernel/trace/blktrace.c:716 blkdev_ioctl+0x6ca/0x16d0 block/ioctl.c:587 block_ioctl+0xd7/0x130 fs/block_dev.c:1894 kobject: 'loop0' (000000005eba4fed): kobject_uevent_env vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x196/0x10c0 fs/ioctl.c:688 ksys_ioctl+0x62/0x90 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6e/0xb0 fs/ioctl.c:710 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 18: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3765 __d_free+0x17/0x20 fs/dcache.c:257 __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+0xbcd/0x19a0 kernel/rcu/tree.c:2881 __do_softirq+0x260/0x92d kernel/softirq.c:292 kobject: 'loop0' (000000005eba4fed): fill_kobj_path: path = '/devices/virtual/block/loop0' The buggy address belongs to the object at ffff88806afc5580 which belongs to the cache dentry(81:syz1) of size 288 The buggy address is located 64 bytes inside of 288-byte region [ffff88806afc5580, ffff88806afc56a0) The buggy address belongs to the page: page:ffffea0001abf140 count:1 mapcount:0 mapping:ffff888092409040 index:0x0 flags: 0x1fffc0000000100(slab) raw: 01fffc0000000100 ffffea0001abf008 ffffea00019dbbc8 ffff888092409040 raw: 0000000000000000 ffff88806afc5000 000000010000000b ffff88808fe74a80 page dumped because: kasan: bad access detected page->mem_cgroup:ffff88808fe74a80 Memory state around the buggy address: ffff88806afc5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806afc5500: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88806afc5580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806afc5600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806afc5680: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb ================================================================== kobject: 'queue' (00000000d7b633fe): kobject_add_internal: parent: 'loop0', set: ''