================================================================== BUG: KASAN: use-after-free in lbmIODone+0xb75/0xe00 fs/jfs/jfs_logmgr.c:2206 Read of size 4 at addr ffff888048315c08 by task loop4/26022 CPU: 0 PID: 26022 Comm: loop4 Not tainted 4.14.222-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load4_noabort+0x68/0x70 mm/kasan/report.c:429 lbmIODone+0xb75/0xe00 fs/jfs/jfs_logmgr.c:2206 bio_endio+0x27a/0x680 block/bio.c:1918 req_bio_endio block/blk-core.c:204 [inline] blk_update_request+0x2d0/0xa30 block/blk-core.c:2765 blk_mq_end_request+0x4c/0x1e0 block/blk-mq.c:530 __blk_mq_complete_request+0x30b/0x6c0 block/blk-mq.c:571 blk_mq_complete_request+0x52/0x60 block/blk-mq.c:591 loop_handle_cmd drivers/block/loop.c:1784 [inline] loop_queue_work+0x227/0x1e80 drivers/block/loop.c:1793 kthread_worker_fn+0x271/0x6c0 kernel/kthread.c:667 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Allocated by task 26012: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] lbmLogInit fs/jfs/jfs_logmgr.c:1842 [inline] lmLogInit+0x2f1/0x12f0 fs/jfs/jfs_logmgr.c:1292 open_inline_log fs/jfs/jfs_logmgr.c:1197 [inline] lmLogOpen+0x6b1/0x10e0 fs/jfs/jfs_logmgr.c:1090 jfs_mount_rw+0x236/0x430 fs/jfs/jfs_mount.c:271 jfs_fill_super+0x78a/0xab0 fs/jfs/super.c:598 mount_bdev+0x2b3/0x360 fs/super.c:1134 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 10651: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 lbmLogShutdown fs/jfs/jfs_logmgr.c:1885 [inline] lmLogShutdown+0x2a9/0x540 fs/jfs/jfs_logmgr.c:1705 lmLogClose+0x464/0x5d0 fs/jfs/jfs_logmgr.c:1481 jfs_umount+0x25f/0x310 fs/jfs/jfs_umount.c:129 jfs_put_super+0x61/0x140 fs/jfs/super.c:223 generic_shutdown_super+0x144/0x370 fs/super.c:446 kill_block_super+0x95/0xe0 fs/super.c:1161 deactivate_locked_super+0x6c/0xd0 fs/super.c:319 deactivate_super+0x7f/0xa0 fs/super.c:350 cleanup_mnt+0x186/0x2c0 fs/namespace.c:1183 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff888048315c00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 8 bytes inside of 192-byte region [ffff888048315c00, ffff888048315cc0) The buggy address belongs to the page: page:ffffea000120c540 count:1 mapcount:0 mapping:ffff888048315000 index:0x0 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff888048315000 0000000000000000 0000000100000010 raw: ffffea0002cff7e0 ffffea00024c7e60 ffff88813fe80040 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888048315b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888048315b80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888048315c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888048315c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888048315d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================