================================================================== BUG: KASAN: use-after-free in debugfs_remove+0x10d/0x130 fs/debugfs/inode.c:685 Read of size 8 at addr ffff88801da691e0 by task kworker/1:1/22 CPU: 1 PID: 22 Comm: kworker/1:1 Not tainted 5.0.0-rc5-next-20190207 #30 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:132 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:2267 worker_thread+0x98/0xe40 kernel/workqueue.c:2413 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Allocated by task 10841: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:498 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:471 kasan_kmalloc mm/kasan/common.c:506 [inline] kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:413 kmem_cache_alloc+0x12d/0x710 mm/slab.c:3543 __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 9: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:460 kasan_slab_free+0xe/0x10 mm/kasan/common.c:468 __cache_free mm/slab.c:3487 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3749 __d_free+0x20/0x30 fs/dcache.c:269 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2486 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2799 [inline] rcu_core+0x928/0x1390 kernel/rcu/tree.c:2780 __do_softirq+0x266/0x95a kernel/softirq.c:292 The buggy address belongs to the object at ffff88801da691a0 which belongs to the cache dentry(81:syz4) of size 288 The buggy address is located 64 bytes inside of 288-byte region [ffff88801da691a0, ffff88801da692c0) The buggy address belongs to the page: page:ffffea0000769a40 count:1 mapcount:0 mapping:ffff888033780a80 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffff888014635a48 ffffea0000763748 ffff888033780a80 raw: 0000000000000000 ffff88801da69040 000000010000000b ffff8880880b4b80 page dumped because: kasan: bad access detected page->mem_cgroup:ffff8880880b4b80 Memory state around the buggy address: ffff88801da69080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801da69100: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88801da69180: fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801da69200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801da69280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================