IPVS: ftp: loaded support on port[0] = 21 audit: type=1804 audit(1541567885.457:60): pid=11938 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor3" name="/root/syzkaller-testdir355513417/syzkaller.kPcUQJ/160/bus" dev="sda1" ino=16580 res=1 overlayfs: failed to resolve './file1': -2 ================================================================== BUG: KASAN: use-after-free in locks_remove_flock+0x33c/0x350 fs/locks.c:2567 Read of size 8 at addr ffff8801cab1bd10 by task syz-executor4/11970 CPU: 1 PID: 11970 Comm: syz-executor4 Not tainted 4.20.0-rc1-next-20181107+ #107 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 locks_remove_flock+0x33c/0x350 fs/locks.c:2567 locks_remove_file+0x148/0x5c0 fs/locks.c:2607 __fput+0x2f0/0xa70 fs/file_table.c:271 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 audit: type=1804 audit(1541567885.467:61): pid=11940 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor3" name="/root/syzkaller-testdir355513417/syzkaller.kPcUQJ/160/bus" dev="sda1" ino=16580 res=1 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 audit: type=1800 audit(1541567885.467:62): pid=11940 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor3" name="bus" dev="sda1" ino=16580 res=0 Code: fd b3 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 b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd1fd672c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000049 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000003 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd1fd6736d4 R13: 00000000004bdd9e R14: 00000000004ccdb8 R15: 00000000ffffffff audit: type=1804 audit(1541567885.507:63): pid=11895 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor4" name="/root/syzkaller-testdir200860518/syzkaller.a9l7yo/161/file0" dev="sda1" ino=16545 res=1 Allocated by task 11970: 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 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 kmem_cache_zalloc include/linux/slab.h:731 [inline] locks_alloc_lock+0x9e/0x300 fs/locks.c:304 flock_make_lock+0x22c/0x2a0 fs/locks.c:438 audit: type=1804 audit(1541567885.517:64): pid=11895 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor4" name="/root/syzkaller-testdir200860518/syzkaller.a9l7yo/161/file0" dev="sda1" ino=16545 res=1 __do_sys_flock fs/locks.c:2057 [inline] __se_sys_flock fs/locks.c:2038 [inline] __x64_sys_flock+0x12b/0x350 fs/locks.c:2038 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 11970: 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:3498 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3760 audit: type=1804 audit(1541567885.537:65): pid=11940 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor3" name="/root/syzkaller-testdir355513417/syzkaller.kPcUQJ/160/bus" dev="sda1" ino=16580 res=1 locks_free_lock+0x295/0x420 fs/locks.c:341 __do_sys_flock fs/locks.c:2078 [inline] __se_sys_flock fs/locks.c:2038 [inline] __x64_sys_flock+0x289/0x350 fs/locks.c:2038 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801cab1bcd0 which belongs to the cache file_lock_cache of size 264 The buggy address is located 64 bytes inside of 264-byte region [ffff8801cab1bcd0, ffff8801cab1bdd8) The buggy address belongs to the page: page:ffffea00072ac6c0 count:1 mapcount:0 mapping:ffff8801d9a1c3c0 index:0xffff8801cab1b000 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffff8801d9a82e38 ffff8801d9a82e38 ffff8801d9a1c3c0 kobject: 'loop3' (00000000b6e1ae91): kobject_uevent_env raw: 0000000000000000 ffff8801cab1b000 000000010000000c 0000000000000000 kobject: 'loop3' (00000000b6e1ae91): fill_kobj_path: path = '/devices/virtual/block/loop3' page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cab1bc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801cab1bc80: fb fb fc fc fc fc fc fc fc fc fb fb fb fb fb fb >ffff8801cab1bd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801cab1bd80: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff8801cab1be00: fc fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================