audit: type=1804 audit(1551816891.111:361): pid=21952 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op=invalid_pcr cause=open_writers comm="syz-executor.3" name="/root/syzkaller-testdir312142175/syzkaller.kWFzet/104/file0/file0" dev="sda1" ino=17777 res=1 XFS (loop4): Invalid superblock magic number ================================================================== BUG: KASAN: use-after-free in debugfs_remove+0x10d/0x130 fs/debugfs/inode.c:685 Read of size 8 at addr ffff8880985be340 by task kworker/0:2/8063 CPU: 0 PID: 8063 Comm: kworker/0:2 Not tainted 5.0.0+ #7 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 debugfs_remove+0x10d/0x130 fs/debugfs/inode.c:685 blk_trace_free+0x38/0x140 kernel/trace/blktrace.c:312 blk_trace_cleanup kernel/trace/blktrace.c:339 [inline] __blk_trace_remove+0x78/0xa0 kernel/trace/blktrace.c:352 blk_trace_shutdown+0x67/0x90 kernel/trace/blktrace.c:752 __blk_release_queue+0x1dc/0x3a0 block/blk-sysfs.c:866 process_one_work+0x98e/0x1790 kernel/workqueue.c:2173 worker_thread+0x98/0xe40 kernel/workqueue.c:2319 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Allocated by task 21852: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:495 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:468 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:503 slab_post_alloc_hook mm/slab.h:440 [inline] slab_alloc mm/slab.c:3388 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3548 __d_alloc+0x2e/0x8c0 fs/dcache.c:1622 d_alloc+0x4d/0x2b0 fs/dcache.c:1701 d_alloc_parallel+0xf4/0x1bc0 fs/dcache.c:2449 __lookup_slow+0x1ab/0x500 fs/namei.c:1654 lookup_one_len+0x16d/0x1a0 fs/namei.c:2543 start_creating fs/debugfs/inode.c:308 [inline] start_creating+0xbf/0x1e0 fs/debugfs/inode.c:284 __debugfs_create_file+0x65/0x400 fs/debugfs/inode.c:347 debugfs_create_file+0x5a/0x70 fs/debugfs/inode.c:400 do_blk_trace_setup+0x376/0xb90 kernel/trace/blktrace.c:528 __blk_trace_setup+0xe3/0x190 kernel/trace/blktrace.c:577 blk_trace_ioctl+0x170/0x300 kernel/trace/blktrace.c:716 blkdev_ioctl+0x12c/0x1c40 block/ioctl.c:591 block_ioctl+0xee/0x130 fs/block_dev.c:1914 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:509 [inline] do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713 __do_sys_ioctl fs/ioctl.c:720 [inline] __se_sys_ioctl fs/ioctl.c:718 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 21855: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:457 kasan_slab_free+0xe/0x10 mm/kasan/common.c:465 __cache_free mm/slab.c:3494 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3754 __d_free+0x20/0x30 fs/dcache.c:269 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2452 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline] rcu_process_callbacks+0x928/0x1390 kernel/rcu/tree.c:2754 __do_softirq+0x266/0x95a kernel/softirq.c:292 The buggy address belongs to the object at ffff8880985be300 which belongs to the cache dentry(33:syz2) of size 288 The buggy address is located 64 bytes inside of 288-byte region [ffff8880985be300, ffff8880985be420) The buggy address belongs to the page: page:ffffea0002616f80 count:1 mapcount:0 mapping:ffff88805a1d3cc0 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00024b04c8 ffffea0001147608 ffff88805a1d3cc0 raw: 0000000000000000 ffff8880985be040 000000010000000b ffff888058b76500 page dumped because: kasan: bad access detected page->mem_cgroup:ffff888058b76500 Memory state around the buggy address: ffff8880985be200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880985be280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880985be300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880985be380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880985be400: fb fb fb fb fc fc fc fc fc fc fc fc fb fb fb fb ==================================================================