================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3829/0x5020 kernel/locking/lockdep.c:3291 Read of size 8 at addr ffff8801d53148b8 by task syz-executor0/9002 CPU: 1 PID: 9002 Comm: syz-executor0 Not tainted 4.18.0-next-20180820+ #43 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+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __lock_acquire+0x3829/0x5020 kernel/locking/lockdep.c:3291 lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901 __mutex_lock_common kernel/locking/mutex.c:925 [inline] __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088 blkdev_get+0x5f2/0xb50 fs/block_dev.c:1623 blkdev_get_by_dev+0x3f/0x80 fs/block_dev.c:1739 lock_rdev+0xa2/0x150 drivers/md/md.c:2294 md_import_device+0x20b/0x4f0 drivers/md/md.c:3473 add_new_disk+0x57c/0x1900 drivers/md/md.c:6360 md_ioctl+0x4b3e/0x63e0 drivers/md/md.c:7378 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x9cd/0x2030 block/ioctl.c:601 block_ioctl+0xee/0x130 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: fd b4 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f42fa346c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f42fa3476d4 RCX: 0000000000457089 RDX: 00000000200000c0 RSI: 0000000040140921 RDI: 0000000000000003 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cd4d0 R14: 00000000004c3f50 R15: 0000000000000000 Allocated by task 9002: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x710 mm/slab.c:3554 bdev_alloc_inode+0x1b/0x40 fs/block_dev.c:730 alloc_inode+0x63/0x190 fs/inode.c:210 iget5_locked+0x12e/0x1d0 fs/inode.c:1123 bdget+0xb7/0x5e0 fs/block_dev.c:871 blkdev_get_by_dev+0x24/0x80 fs/block_dev.c:1735 lock_rdev+0xa2/0x150 drivers/md/md.c:2294 md_import_device+0x20b/0x4f0 drivers/md/md.c:3473 add_new_disk+0x57c/0x1900 drivers/md/md.c:6360 md_ioctl+0x4b3e/0x63e0 drivers/md/md.c:7378 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x9cd/0x2030 block/ioctl.c:601 block_ioctl+0xee/0x130 fs/block_dev.c:1883 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4492: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x280 mm/slab.c:3756 bdev_i_callback+0x20/0x30 fs/block_dev.c:741 __rcu_reclaim kernel/rcu/rcu.h:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf78/0x27c0 kernel/rcu/tree.c:2864 __do_softirq+0x2eb/0xa74 kernel/softirq.c:292 The buggy address belongs to the object at ffff8801d5314840 which belongs to the cache bdev_cache of size 1336 The buggy address is located 120 bytes inside of 1336-byte region [ffff8801d5314840, ffff8801d5314d78) The buggy address belongs to the page: page:ffffea000754c500 count:1 mapcount:0 mapping:ffff8801dad754c0 index:0xffff8801d5314ffe flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea000754e548 ffff8801dad74548 ffff8801dad754c0 raw: ffff8801d5314ffe ffff8801d5314280 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d5314780: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff8801d5314800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8801d5314880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d5314900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d5314980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================