syzbot


possible deadlock in dquot_commit (2)

Status: upstream: reported C repro on 2022/10/08 19:13
Reported-by: syzbot+70ff52e51b7e7714db8a@syzkaller.appspotmail.com
First crash: 53d, last: 45m

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: possible deadlock in dquot_commit (log)
Repro: C syz .config
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 possible deadlock in dquot_commit C error 8 38d 564d 0/1 upstream: reported C repro on 2021/05/11 01:53
upstream possible deadlock in dquot_commit C unreliable 41 354d 654d 22/24 fixed on 2022/03/08 16:11
linux-4.19 possible deadlock in dquot_commit C error 61 19h01m 788d 0/1 upstream: reported C repro on 2020/09/29 12:02

Sample crash report:
loop0: detected capacity change from 0 to 512
EXT4-fs (loop0): revision level too high, forcing read-only mode
EXT4-fs (loop0): orphan cleanup on readonly fs
======================================================
WARNING: possible circular locking dependency detected
6.1.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor335/3813 is trying to acquire lock:
ffff888071697ae8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x58/0x4e0 fs/quota/dquot.c:479

but task is already holding lock:
ffff8880715aa0a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0xa06/0xeb0 fs/ext4/inode.c:4259

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       down_read+0x39/0x50 kernel/locking/rwsem.c:1509
       ext4_map_blocks+0x398/0x1cc0 fs/ext4/inode.c:568
       ext4_getblk+0x1b9/0x770 fs/ext4/inode.c:858
       ext4_bread+0x2a/0x170 fs/ext4/inode.c:914
       ext4_quota_write+0x225/0x570 fs/ext4/super.c:7082
       write_blk fs/quota/quota_tree.c:64 [inline]
       get_free_dqblk+0x34a/0x6d0 fs/quota/quota_tree.c:130
       do_insert_tree+0x271/0x1b50 fs/quota/quota_tree.c:340
       do_insert_tree+0x744/0x1b50 fs/quota/quota_tree.c:375
       dq_insert_tree fs/quota/quota_tree.c:401 [inline]
       qtree_write_dquot+0x3b6/0x530 fs/quota/quota_tree.c:420
       v2_write_dquot+0x11b/0x190 fs/quota/quota_v2.c:358
       dquot_acquire+0x348/0x670 fs/quota/dquot.c:444
       ext4_acquire_dquot+0x2e0/0x400 fs/ext4/super.c:6738
       dqget+0x999/0xdc0 fs/quota/dquot.c:914
       __dquot_initialize+0x3d0/0xcf0 fs/quota/dquot.c:1492
       ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
       ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474
       __ext4_fill_super fs/ext4/super.c:5515 [inline]
       ext4_fill_super+0x80ed/0x8610 fs/ext4/super.c:5643
       get_tree_bdev+0x400/0x620 fs/super.c:1324
       vfs_get_tree+0x88/0x270 fs/super.c:1531
       do_new_mount+0x289/0xad0 fs/namespace.c:3040
       do_mount fs/namespace.c:3383 [inline]
       __do_sys_mount fs/namespace.c:3591 [inline]
       __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       down_read+0x39/0x50 kernel/locking/rwsem.c:1509
       v2_read_dquot+0x4a/0x100 fs/quota/quota_v2.c:332
       dquot_acquire+0x186/0x670 fs/quota/dquot.c:435
       ext4_acquire_dquot+0x2e0/0x400 fs/ext4/super.c:6738
       dqget+0x999/0xdc0 fs/quota/dquot.c:914
       __dquot_initialize+0x291/0xcf0 fs/quota/dquot.c:1492
       ext4_process_orphan+0x57/0x2d0 fs/ext4/orphan.c:329
       ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474
       __ext4_fill_super fs/ext4/super.c:5515 [inline]
       ext4_fill_super+0x80ed/0x8610 fs/ext4/super.c:5643
       get_tree_bdev+0x400/0x620 fs/super.c:1324
       vfs_get_tree+0x88/0x270 fs/super.c:1531
       do_new_mount+0x289/0xad0 fs/namespace.c:3040
       do_mount fs/namespace.c:3383 [inline]
       __do_sys_mount fs/namespace.c:3591 [inline]
       __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3097 [inline]
       check_prevs_add kernel/locking/lockdep.c:3216 [inline]
       validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
       __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
       lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
       __mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
       dquot_commit+0x58/0x4e0 fs/quota/dquot.c:479
       ext4_write_dquot+0x1e4/0x2b0 fs/ext4/super.c:6722
       mark_dquot_dirty fs/quota/dquot.c:346 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
       __dquot_free_space+0x9a8/0xfb0 fs/quota/dquot.c:1907
       dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
       dquot_free_space include/linux/quotaops.h:384 [inline]
       dquot_free_block include/linux/quotaops.h:395 [inline]
       ext4_mb_clear_bb fs/ext4/mballoc.c:6050 [inline]
       ext4_free_blocks+0x1c4a/0x2810 fs/ext4/mballoc.c:6179
       ext4_clear_blocks+0x334/0x3a0 fs/ext4/indirect.c:880
       ext4_free_data fs/ext4/indirect.c:941 [inline]
       ext4_ind_truncate+0x3fe/0xd70 fs/ext4/indirect.c:1146
       ext4_truncate+0xa62/0xeb0 fs/ext4/inode.c:4266
       ext4_evict_inode+0xbbc/0x1010 fs/ext4/inode.c:286
       evict+0x2a4/0x620 fs/inode.c:664
       ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474
       __ext4_fill_super fs/ext4/super.c:5515 [inline]
       ext4_fill_super+0x80ed/0x8610 fs/ext4/super.c:5643
       get_tree_bdev+0x400/0x620 fs/super.c:1324
       vfs_get_tree+0x88/0x270 fs/super.c:1531
       do_new_mount+0x289/0xad0 fs/namespace.c:3040
       do_mount fs/namespace.c:3383 [inline]
       __do_sys_mount fs/namespace.c:3591 [inline]
       __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  &dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_data_sem/2);
                               lock(&s->s_dquot.dqio_sem);
                               lock(&ei->i_data_sem/2);
  lock(&dquot->dq_lock);

 *** DEADLOCK ***

4 locks held by syz-executor335/3813:
 #0: ffff88801e1c00e0 (&type->s_umount_key#28/1){+.+.}-{3:3}, at: alloc_super+0x212/0x920 fs/super.c:228
 #1: ffff88801e1c0650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1826 [inline]
 #1: ffff88801e1c0650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1948 [inline]
 #1: ffff88801e1c0650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x4b7/0x1010 fs/ext4/inode.c:240
 #2: ffff8880715aa0a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0xa06/0xeb0 fs/ext4/inode.c:4259
 #3: ffffffff8d46c588 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:303

stack backtrace:
CPU: 0 PID: 3813 Comm: syz-executor335 Not tainted 6.1.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
 check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2177
 check_prev_add kernel/locking/lockdep.c:3097 [inline]
 check_prevs_add kernel/locking/lockdep.c:3216 [inline]
 validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
 __mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
 dquot_commit+0x58/0x4e0 fs/quota/dquot.c:479
 ext4_write_dquot+0x1e4/0x2b0 fs/ext4/super.c:6722
 mark_dquot_dirty fs/quota/dquot.c:346 [inline]
 mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
 __dquot_free_space+0x9a8/0xfb0 fs/quota/dquot.c:1907
 dquot_free_space_nodirty include/linux/quotaops.h:379 [inline]
 dquot_free_space include/linux/quotaops.h:384 [inline]
 dquot_free_block include/linux/quotaops.h:395 [inline]
 ext4_mb_clear_bb fs/ext4/mballoc.c:6050 [inline]
 ext4_free_blocks+0x1c4a/0x2810 fs/ext4/mballoc.c:6179
 ext4_clear_blocks+0x334/0x3a0 fs/ext4/indirect.c:880
 ext4_free_data fs/ext4/indirect.c:941 [inline]
 ext4_ind_truncate+0x3fe/0xd70 fs/ext4/indirect.c:1146
 ext4_truncate+0xa62/0xeb0 fs/ext4/inode.c:4266
 ext4_evict_inode+0xbbc/0x1010 fs/ext4/inode.c:286
 evict+0x2a4/0x620 fs/inode.c:664
 ext4_orphan_cleanup+0xb60/0x1340 fs/ext4/orphan.c:474
 __ext4_fill_super fs/ext4/super.c:5515 [inline]
 ext4_fill_super+0x80ed/0x8610 fs/ext4/super.c:5643
 get_tree_bdev+0x400/0x620 fs/super.c:1324
 vfs_get_tree+0x88/0x270 fs/super.c:1531
 do_new_mount+0x289/0xad0 fs/namespace.c:3040
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f90f3cc7baa
Code: 48 c7 c2 c0 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 a8 00 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdfcd402f8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f90f3cc7baa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffdfcd40310
RBP: 00007ffdfcd40310 R08: 00007ffdfcd40350 R09: 000055555625b2c0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004
R13: 00007ffdfcd40350 R14: 0000000000000026 R15: 0000000020000590
 </TASK>
EXT4-fs error (device loop0): mb_free_blocks:1780: group 0, inode 11: block 33:freeing already freed block (bit 32); block bitmap corrupt.
EXT4-fs (loop0): 1 orphan inode deleted
syz-executor335 (3813) used greatest stack depth: 16376 bytes left

Crashes (652):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-fs 2022/11/21 10:19 upstream eb7081409f94 5bb70014 .config log report syz C possible deadlock in dquot_commit
ci-upstream-kasan-gce-root 2022/11/15 16:00 upstream e01d50cbd6ee 97de9cfc .config log report syz C possible deadlock in dquot_commit
ci-upstream-linux-next-kasan-gce-root 2022/11/20 13:36 linux-next 15f3bff12cf6 5bb70014 .config log report syz C possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/11/06 15:00 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 6d752409 .config log report syz C possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/10/26 20:32 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 2159e4d2 .config log report syz C possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/10/19 16:17 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 b31320fc .config log report syz C possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/10/17 20:44 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 67cb024c .config log report syz C possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/10/11 08:20 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 2b253ced .config log report syz C possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/10/10 22:20 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bbed346d5a96 aea5da89 .config log report syz C possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/27 00:44 upstream 644e9524388a f4470a7b .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/26 21:05 upstream 644e9524388a f4470a7b .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/26 17:46 upstream 644e9524388a f4470a7b .config log report info possible deadlock in dquot_commit
ci-upstream-kasan-gce-root 2022/11/22 01:15 upstream eb7081409f94 1c576c23 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/21 17:12 upstream eb7081409f94 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/21 15:42 upstream eb7081409f94 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/21 13:27 upstream eb7081409f94 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/21 09:08 upstream eb7081409f94 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/21 07:07 upstream eb7081409f94 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/21 02:46 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/21 02:09 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/21 00:37 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 23:34 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 22:01 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 20:26 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 19:04 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 16:51 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 16:12 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 15:09 upstream 77c51ba552a1 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 11:15 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 10:11 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 08:57 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 07:38 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 06:32 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 03:27 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 02:57 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 01:18 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/20 00:11 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 22:22 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 19:07 upstream fe24a97cf254 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 16:09 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 15:20 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 14:18 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 13:12 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 11:59 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 10:31 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 09:19 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 08:18 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/11/19 06:20 upstream ab290eaddc4c 5bb70014 .config log report info possible deadlock in dquot_commit
ci-upstream-kasan-gce-selinux-root 2022/11/18 13:35 upstream 84368d882b96 4ba8ab94 .config log report info possible deadlock in dquot_commit
ci-qemu-upstream 2022/11/12 16:30 upstream 8f2975c2bb4c f42ee5d8 .config log report info possible deadlock in dquot_commit
ci-upstream-kasan-gce-smack-root 2022/11/04 10:33 upstream ee6050c8af96 6d752409 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/10/08 04:12 upstream 4c86114194e6 79a59635 .config log report info possible deadlock in dquot_commit
ci2-upstream-fs 2022/10/04 19:11 upstream 4fe89d07dcc2 eab8f949 .config log report info possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/11/26 18:55 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 6d464646530f 74a66371 .config log report info possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/11/23 12:10 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 65762d97e6fa 75740b3f .config log report info possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/11/22 13:26 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a77d28d13789 1c576c23 .config log report info possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/11/21 11:48 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 9500fc6e9e60 5bb70014 .config log report info possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/11/21 04:59 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 9500fc6e9e60 5bb70014 .config log report info possible deadlock in dquot_commit
ci-upstream-gce-arm64 2022/11/19 17:48 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 9500fc6e9e60 5bb70014 .config log report info possible deadlock in dquot_commit
* Struck through repros no longer work on HEAD.