syzbot


WARNING: bad unlock balance in ext4_rename2

Status: fixed on 2023/06/08 14:41
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+0c73d1d8b952c5f3d714@syzkaller.appspotmail.com
Fix commit: 70e42feab2e2 ext4: fix possible double unlock when moving a directory
First crash: 449d, last: 425d
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [ext4?] WARNING: bad unlock balance in ext4_rename2 2 (3) 2023/04/30 05:24
[bug report] ext4: Fix possible corruption when moving a directory 5 (5) 2023/03/20 11:03
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING: bad unlock balance in ext4_rename2 16 427d 431d 0/3 auto-obsoleted due to no activity on 2023/06/20 08:44
linux-6.1 WARNING: bad unlock balance in ext4_rename2 21 427d 432d 0/3 auto-obsoleted due to no activity on 2023/06/20 09:41

Sample crash report:
EXT4-fs error (device loop5): ext4_get_first_dir_block:3521: inode #12: block 32: comm syz-executor.5: bad entry in directory: inode out of bounds - offset=0, inode=7948, rec_len=12, size=2048 fake=1
EXT4-fs error (device loop5): ext4_get_first_dir_block:3524: inode #12: comm syz-executor.5: directory missing '.'
=====================================
WARNING: bad unlock balance detected!
6.3.0-rc2-syzkaller-00405-ga3671bd86a97 #0 Not tainted
-------------------------------------
syz-executor.5/13539 is trying to release lock (&type->i_mutex_dir_key) at:
[<ffffffff824000a5>] inode_unlock include/linux/fs.h:763 [inline]
[<ffffffff824000a5>] ext4_rename fs/ext4/namei.c:4029 [inline]
[<ffffffff824000a5>] ext4_rename2+0x15a5/0x4440 fs/ext4/namei.c:4202
but there are no more locks to release!

other info that might help us debug this:
3 locks held by syz-executor.5/13539:
 #0: ffff88801fd7c460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:394
 #1: ffff88802f3bd440 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: lock_rename+0x186/0x1a0
 #2: ffff88807439b628 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff88807439b628 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_rename+0x617/0xfa0 fs/namei.c:4744

stack backtrace:
CPU: 0 PID: 13539 Comm: syz-executor.5 Not tainted 6.3.0-rc2-syzkaller-00405-ga3671bd86a97 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_unlock_imbalance_bug+0x252/0x2c0 kernel/locking/lockdep.c:5109
 __lock_release kernel/locking/lockdep.c:5346 [inline]
 lock_release+0x59d/0x9d0 kernel/locking/lockdep.c:5689
 up_write+0x79/0x580 kernel/locking/rwsem.c:1625
 inode_unlock include/linux/fs.h:763 [inline]
 ext4_rename fs/ext4/namei.c:4029 [inline]
 ext4_rename2+0x15a5/0x4440 fs/ext4/namei.c:4202
 vfs_rename+0xb1b/0xfa0 fs/namei.c:4772
 do_renameat2+0xb9b/0x13c0 fs/namei.c:4923
 __do_sys_rename fs/namei.c:4969 [inline]
 __se_sys_rename fs/namei.c:4967 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:4967
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f354588c0f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007f353c03e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f35459ac050 RCX: 00007f354588c0f9
RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000020000280
RBP: 00007f35458e7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff0609042f R14: 00007f353c03e300 R15: 0000000000022000
 </TASK>
------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff88807439abb0, owner = 0x1, curr 0xffff88802f66d7c0, list empty
WARNING: CPU: 1 PID: 13539 at kernel/locking/rwsem.c:1370 __up_write kernel/locking/rwsem.c:1369 [inline]
WARNING: CPU: 1 PID: 13539 at kernel/locking/rwsem.c:1370 up_write+0x4f4/0x580 kernel/locking/rwsem.c:1626
Modules linked in:
CPU: 1 PID: 13539 Comm: syz-executor.5 Not tainted 6.3.0-rc2-syzkaller-00405-ga3671bd86a97 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
RIP: 0010:__up_write kernel/locking/rwsem.c:1369 [inline]
RIP: 0010:up_write+0x4f4/0x580 kernel/locking/rwsem.c:1626
Code: 48 c7 c7 a0 71 ea 8a 48 c7 c6 e0 73 ea 8a 48 8b 54 24 28 48 8b 4c 24 18 4d 89 e0 4c 8b 4c 24 30 53 e8 00 ef e8 ff 48 83 c4 08 <0f> 0b e9 75 fd ff ff 48 c7 c1 a8 b0 53 8e 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc9000b32f680 EFLAGS: 00010292
RAX: 88e767d59c119600 RBX: ffffffff8aea7280 RCX: 0000000000040000
RDX: ffffc9000bb5b000 RSI: 000000000003ffff RDI: 0000000000040000
RBP: ffffc9000b32f750 R08: ffffffff81527d42 R09: fffff52001665e49
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: ffff88807439abb0 R14: 1ffff92001665ed8 R15: dffffc0000000000
FS:  00007f353c03e700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa5afb821b8 CR3: 00000000211de000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:763 [inline]
 ext4_rename fs/ext4/namei.c:4029 [inline]
 ext4_rename2+0x15a5/0x4440 fs/ext4/namei.c:4202
 vfs_rename+0xb1b/0xfa0 fs/namei.c:4772
 do_renameat2+0xb9b/0x13c0 fs/namei.c:4923
 __do_sys_rename fs/namei.c:4969 [inline]
 __se_sys_rename fs/namei.c:4967 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:4967
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f354588c0f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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:00007f353c03e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007f35459ac050 RCX: 00007f354588c0f9
RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000020000280
RBP: 00007f35458e7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff0609042f R14: 00007f353c03e300 R15: 0000000000022000
 </TASK>

Crashes (105):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/19 17:10 upstream a3671bd86a97 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/03/19 15:18 upstream a3671bd86a97 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING: bad unlock balance in ext4_rename2
2023/03/19 07:57 upstream a3671bd86a97 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING: bad unlock balance in ext4_rename2
2023/03/19 03:57 upstream 534293368afa 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/03/19 02:25 upstream 534293368afa 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/03/18 19:02 upstream 478a351ce0d6 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/03/18 17:54 upstream 478a351ce0d6 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/03/17 22:47 upstream 38e04b3e4240 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/03/17 01:47 upstream 0ddc84d2dd43 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/03/16 10:48 upstream 9c1bec9c0b08 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/03/04 13:47 upstream 0988a0ea7919 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs WARNING: bad unlock balance in ext4_rename2
2023/02/28 19:56 upstream e492250d5252 95aee97a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING: bad unlock balance in ext4_rename2
2023/03/24 16:34 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 9700afae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/24 06:34 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/23 20:47 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/23 18:22 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/23 03:38 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/23 00:46 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/22 23:29 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/22 10:48 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e d846e076 .config console log report info ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/22 07:46 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 8b4eb097 .config console log report info ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/22 04:40 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 8b4eb097 .config console log report info ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/21 23:55 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 8b4eb097 .config console log report info ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/21 22:25 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 8b4eb097 .config console log report info ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/21 20:41 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 03fb9538 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/21 12:25 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 03fb9538 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/21 10:25 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 03fb9538 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/20 17:05 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/20 15:07 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/20 14:03 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/20 12:42 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/20 08:38 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/20 07:14 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/20 04:46 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/19 21:21 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/19 13:00 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/19 01:17 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/18 11:40 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/18 08:17 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/18 05:19 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/18 03:00 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/18 00:03 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/17 21:42 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 7939252e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/17 13:32 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/16 05:21 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/15 14:11 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/15 11:03 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 0d5c4377 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/15 08:08 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 0d5c4377 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/15 05:12 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 0d5c4377 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
2023/03/15 00:13 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fe15c26ee26e 0d5c4377 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING: bad unlock balance in ext4_rename2
* Struck through repros no longer work on HEAD.