syzbot


BUG: Dentry still in use [unmount of f2fs loop0]

Status: upstream: reported C repro on 2021/02/28 19:03
Reported-by: syzbot+1395325cd9864b352f06@syzkaller.appspotmail.com
First crash: 646d, last: 646d

Sample crash report:
incfs: Can't find or create .index dir in ./file0
BUG: Dentry 00000000fc7a8954{i=0,n=.index}  still in use (1) [unmount of f2fs loop0]
------------[ cut here ]------------
WARNING: CPU: 1 PID: 350 at fs/dcache.c:1597 umount_check+0x179/0x1c0 fs/dcache.c:1588
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 350 Comm: syz-executor677 Not tainted 5.4.101-syzkaller-00440-g55e9d3c6b5f7 #0
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+0x1d8/0x24e lib/dump_stack.c:118
 panic+0x285/0x740 kernel/panic.c:221
 __warn+0x1f1/0x200 kernel/panic.c:582
 report_bug+0x380/0x4d0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 do_error_trap arch/x86/kernel/traps.c:272 [inline]
 do_invalid_op+0x6e/0x110 arch/x86/kernel/traps.c:291
 invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:1029
RIP: 0010:umount_check+0x179/0x1c0 fs/dcache.c:1588
Code: ff 4c 8b 0b 48 81 c5 20 04 00 00 48 c7 c7 00 d1 e8 84 4c 89 fe 4c 89 f2 4c 89 f9 45 89 e8 31 c0 55 e8 d7 3a b0 ff 48 83 c4 08 <0f> 0b e9 fd fe ff ff 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c d4 fe ff
RSP: 0018:ffff8881dc85f640 EFLAGS: 00010292
RAX: 0000000000000054 RBX: ffffffff85ff2dc0 RCX: 604bf155b4a2d900
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000
RBP: ffff8881dfa55420 R08: ffffffff814e6247 R09: ffffed103ede5e08
R10: ffffed103ede5e08 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881dfe0edd0
 d_walk+0x2d9/0x540 fs/dcache.c:1307
 do_one_tree fs/dcache.c:1604 [inline]
 shrink_dcache_for_umount+0x8a/0x1a0 fs/dcache.c:1620
 generic_shutdown_super+0x63/0x2a0 fs/super.c:447
 kill_block_super+0x79/0xd0 fs/super.c:1444
 kill_f2fs_super+0x29d/0x330 fs/f2fs/super.c:3988
 deactivate_locked_super+0xaf/0x100 fs/super.c:335
 deactivate_super+0x1b3/0x270 fs/super.c:366
 cleanup_mnt+0x432/0x4e0 fs/namespace.c:1102
 task_work_run+0x186/0x1b0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xcb9/0x2bf0 kernel/exit.c:812
 do_group_exit+0x15c/0x2c0 kernel/exit.c:910
 get_signal+0x164f/0x1fc0 kernel/signal.c:2745
 do_signal+0x92/0x5c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop arch/x86/entry/common.c:159 [inline]
 prepare_exit_to_usermode+0x207/0x310 arch/x86/entry/common.c:194
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x44a389
Code: Bad RIP value.
RSP: 002b:00007f026ca652f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00000000004cb410 RCX: 000000000044a389
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00000000004cb41c
RBP: 0030656c69662f2e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0300000000000000
R13: 0300000000030001 R14: 0000000100000003 R15: 00000000004cb418
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-android-5-4-kasan 2021/02/28 19:02 android12-5.4 55e9d3c6b5f7 4c37c133 .config log report syz C BUG: Dentry still in use [unmount of f2fs loop0]
* Struck through repros no longer work on HEAD.