syzbot


WARNING: bad unlock balance in btrfs_direct_write

Status: fixed on 2024/10/03 15:25
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+7dbbb74af6291b5a5a8b@syzkaller.appspotmail.com
Fix commit: e0391e92f9ab btrfs: fix double inode unlock for direct IO sync writes
First crash: 124d, last: 117d
Cause bisection: introduced by (bisect log) :
commit 939b656bc8ab203fdbde26ccac22bcb7f0985be5
Author: Filipe Manana <fdmanana@suse.com>
Date: Fri Jul 26 10:12:52 2024 +0000

  btrfs: fix corruption after buffer fault in during direct IO append write

Crash: WARNING: bad unlock balance in btrfs_direct_write (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] btrfs: Add missing skip-lock for locks 2 (2) 2024/08/02 12:29
[syzbot] [btrfs?] WARNING: bad unlock balance in btrfs_direct_write 1 (3) 2024/08/02 11:51
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/08/02 11:29 21m eadavis@qq.com patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e4fc196f5ba3 OK log

Sample crash report:
=====================================
WARNING: bad unlock balance detected!
6.11.0-rc1-syzkaller-00062-ge4fc196f5ba3 #0 Not tainted
-------------------------------------
syz-executor334/5219 is trying to release lock (&sb->s_type->i_mutex_key) at:
[<ffffffff83d47c3f>] btrfs_direct_write+0x91f/0xb40 fs/btrfs/direct-io.c:920
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syz-executor334/5219:
 #0: ffff888026aee420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2876 [inline]
 #0: ffff888026aee420 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x227/0xc90 fs/read_write.c:586

stack backtrace:
CPU: 0 UID: 0 PID: 5219 Comm: syz-executor334 Not tainted 6.11.0-rc1-syzkaller-00062-ge4fc196f5ba3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_unlock_imbalance_bug+0x256/0x2c0 kernel/locking/lockdep.c:5199
 __lock_release kernel/locking/lockdep.c:5436 [inline]
 lock_release+0x5cb/0xa30 kernel/locking/lockdep.c:5780
 up_write+0x79/0x590 kernel/locking/rwsem.c:1631
 btrfs_direct_write+0x91f/0xb40 fs/btrfs/direct-io.c:920
 btrfs_do_write_iter+0x2a1/0x760 fs/btrfs/file.c:1505
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa72/0xc90 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb1e35fc169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcc8975c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0073746e6576652e RCX: 00007fb1e35fc169
RDX: 0000000000182000 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 652e79726f6d656d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcc8975ca0
R13: 00007ffcc8975ce0 R14: 0000000001000000 R15: 0000000000000003
 </TASK>
------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888073c98d20, owner = 0x0, curr 0xffff88807dba1e00, list empty
WARNING: CPU: 1 PID: 5219 at kernel/locking/rwsem.c:1370 __up_write kernel/locking/rwsem.c:1369 [inline]
WARNING: CPU: 1 PID: 5219 at kernel/locking/rwsem.c:1370 up_write+0x502/0x590 kernel/locking/rwsem.c:1632
Modules linked in:
CPU: 1 UID: 0 PID: 5219 Comm: syz-executor334 Not tainted 6.11.0-rc1-syzkaller-00062-ge4fc196f5ba3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:__up_write kernel/locking/rwsem.c:1369 [inline]
RIP: 0010:up_write+0x502/0x590 kernel/locking/rwsem.c:1632
Code: c7 c7 a0 c8 ea 8b 48 c7 c6 20 cb ea 8b 48 8b 54 24 28 48 8b 4c 24 18 4d 89 e0 4c 8b 4c 24 30 53 e8 d3 9c e6 ff 48 83 c4 08 90 <0f> 0b 90 90 e9 6a fd ff ff 48 c7 c1 00 a9 f6 8f 80 e1 07 80 c1 03
RSP: 0018:ffffc900033cf920 EFLAGS: 00010292
RAX: b9b6859016ed5300 RBX: ffffffff8beac980 RCX: ffff88807dba1e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900033cf9f0 R08: ffffffff81559202 R09: 1ffff92000679ec4
R10: dffffc0000000000 R11: fffff52000679ec5 R12: 0000000000000000
R13: ffff888073c98d20 R14: 1ffff92000679f2c R15: dffffc0000000000
FS:  000055556574c380(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559a77f63218 CR3: 0000000077ac4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 btrfs_direct_write+0x91f/0xb40 fs/btrfs/direct-io.c:920
 btrfs_do_write_iter+0x2a1/0x760 fs/btrfs/file.c:1505
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa72/0xc90 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb1e35fc169
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcc8975c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0073746e6576652e RCX: 00007fb1e35fc169
RDX: 0000000000182000 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 652e79726f6d656d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcc8975ca0
R13: 00007ffcc8975ce0 R14: 0000000001000000 R15: 0000000000000003
 </TASK>

Crashes (235):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/31 18:40 upstream e4fc196f5ba3 6fde257d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/07/31 17:31 upstream e4fc196f5ba3 6fde257d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/07/31 16:18 upstream e4fc196f5ba3 6fde257d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/07/31 15:11 upstream e4fc196f5ba3 6fde257d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/07/31 14:14 upstream e4fc196f5ba3 6fde257d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/07/31 13:04 upstream e4fc196f5ba3 6fde257d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/07 16:33 upstream d4560686726f 109d2082 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/07 15:10 upstream d4560686726f 7b2f2f35 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: bad unlock balance in btrfs_direct_write
2024/08/07 11:44 upstream d4560686726f 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/07 08:56 upstream d4560686726f 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/07 04:20 upstream eb5e56d14912 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/07 03:09 upstream eb5e56d14912 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/07 02:05 upstream eb5e56d14912 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 22:48 upstream eb5e56d14912 e1bdb00a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 19:47 upstream eb5e56d14912 e1bdb00a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 19:09 upstream eb5e56d14912 1ef9fe42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 12:42 upstream b446a2dae984 e1bdb00a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 11:36 upstream b446a2dae984 e1bdb00a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 10:04 upstream b446a2dae984 e1bdb00a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 08:09 upstream b446a2dae984 e1bdb00a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 04:40 upstream b446a2dae984 e1bdb00a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/06 03:21 upstream b446a2dae984 e35c337f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 18:41 upstream de9c2c66ad8e e35c337f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 17:29 upstream de9c2c66ad8e e35c337f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 16:15 upstream de9c2c66ad8e e35c337f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 13:18 upstream de9c2c66ad8e e35c337f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 11:18 upstream de9c2c66ad8e e35c337f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 08:20 upstream de9c2c66ad8e 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 06:58 upstream de9c2c66ad8e 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 05:16 upstream a5dbd76a8942 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 02:57 upstream a5dbd76a8942 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/05 01:47 upstream a5dbd76a8942 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 17:46 upstream a5dbd76a8942 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 16:02 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 13:45 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 11:29 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 10:19 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 09:09 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 07:45 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 05:50 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 04:16 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 02:54 upstream defaf1a2113a 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/04 00:44 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/03 23:00 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/03 21:21 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/03 20:08 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/03 19:03 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/03 18:03 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/03 16:36 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: bad unlock balance in btrfs_direct_write
2024/08/03 15:28 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
2024/08/03 15:07 upstream 17712b7ea075 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in btrfs_direct_write
* Struck through repros no longer work on HEAD.