syzbot


possible deadlock in ext4_move_extents

Status: upstream: reported on 2022/11/05 16:08
Subsystems: ext4 (incorrect?)
Reported-by: syzbot+1fec0eebb32ecfda77fd@syzkaller.appspotmail.com
First crash: 141d, last: 13m

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc3-syzkaller-00338-gda8e7da11e4b #0 Not tainted
------------------------------------------------------
syz-executor.3/8908 is trying to acquire lock:
ffff888074f72aa8 (&ei->i_data_sem/1){+.+.}-{3:3}, at: ext4_move_extents+0x37d/0xe40 fs/ext4/move_extent.c:620

but task is already holding lock:
ffff88803cb8beb8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_double_down_write_data_sem+0x2c/0x50

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&ei->i_data_sem/2){++++}-{3:3}:
       lock_acquire+0x1e1/0x520 kernel/locking/lockdep.c:5669
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1573
       ext4_map_blocks+0x980/0x1cf0 fs/ext4/inode.c:644
       ext4_getblk+0x1ef/0x7c0 fs/ext4/inode.c:863
       ext4_bread+0x2e/0x180 fs/ext4/inode.c:919
       ext4_quota_write+0x222/0x580 fs/ext4/super.c:7135
       write_blk fs/quota/quota_tree.c:64 [inline]
       find_free_dqentry fs/quota/quota_tree.c:312 [inline]
       do_insert_tree+0xe07/0x1a60 fs/quota/quota_tree.c:373
       do_insert_tree+0x70f/0x1a60 fs/quota/quota_tree.c:375
       do_insert_tree+0x70f/0x1a60 fs/quota/quota_tree.c:375
       do_insert_tree+0x70f/0x1a60 fs/quota/quota_tree.c:375
       dq_insert_tree fs/quota/quota_tree.c:401 [inline]
       qtree_write_dquot+0x3bd/0x530 fs/quota/quota_tree.c:420
       v2_write_dquot+0x120/0x190 fs/quota/quota_v2.c:358
       dquot_acquire+0x351/0x680 fs/quota/dquot.c:444
       ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6770
       dqget+0x98f/0xdb0 fs/quota/dquot.c:914
       __dquot_initialize+0x462/0xe20 fs/quota/dquot.c:1492
       ext4_create+0xb5/0x550 fs/ext4/namei.c:2801
       lookup_open fs/namei.c:3416 [inline]
       open_last_lookups fs/namei.c:3484 [inline]
       path_openat+0x13df/0x3170 fs/namei.c:3712
       do_filp_open+0x234/0x490 fs/namei.c:3742
       do_sys_openat2+0x13f/0x500 fs/open.c:1348
       do_sys_open fs/open.c:1364 [inline]
       __do_sys_open fs/open.c:1372 [inline]
       __se_sys_open fs/open.c:1368 [inline]
       __x64_sys_open+0x225/0x270 fs/open.c:1368
       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

-> #2 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       lock_acquire+0x1e1/0x520 kernel/locking/lockdep.c:5669
       down_read+0x3d/0x50 kernel/locking/rwsem.c:1520
       v2_read_dquot+0x4e/0x110 fs/quota/quota_v2.c:332
       dquot_acquire+0x18c/0x680 fs/quota/dquot.c:435
       ext4_acquire_dquot+0x2e6/0x400 fs/ext4/super.c:6770
       dqget+0x98f/0xdb0 fs/quota/dquot.c:914
       __dquot_initialize+0x2dd/0xe20 fs/quota/dquot.c:1492
       ext4_create+0xb5/0x550 fs/ext4/namei.c:2801
       lookup_open fs/namei.c:3416 [inline]
       open_last_lookups fs/namei.c:3484 [inline]
       path_openat+0x13df/0x3170 fs/namei.c:3712
       do_filp_open+0x234/0x490 fs/namei.c:3742
       do_sys_openat2+0x13f/0x500 fs/open.c:1348
       do_sys_open fs/open.c:1364 [inline]
       __do_sys_creat fs/open.c:1440 [inline]
       __se_sys_creat fs/open.c:1434 [inline]
       __x64_sys_creat+0x123/0x160 fs/open.c:1434
       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

-> #1 (&dquot->dq_lock){+.+.}-{3:3}:
       lock_acquire+0x1e1/0x520 kernel/locking/lockdep.c:5669
       __mutex_lock_common+0x1d8/0x2530 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:799
       dquot_commit+0x5b/0x520 fs/quota/dquot.c:479
       ext4_write_dquot+0x1f2/0x2c0 fs/ext4/super.c:6754
       mark_dquot_dirty fs/quota/dquot.c:346 [inline]
       mark_all_dquot_dirty fs/quota/dquot.c:384 [inline]
       __dquot_alloc_space+0x54c/0xf50 fs/quota/dquot.c:1722
       dquot_alloc_space_nodirty include/linux/quotaops.h:300 [inline]
       dquot_alloc_space include/linux/quotaops.h:313 [inline]
       swap_inode_boot_loader fs/ext4/ioctl.c:491 [inline]
       __ext4_ioctl fs/ext4/ioctl.c:1418 [inline]
       ext4_ioctl+0x523d/0x5b30 fs/ext4/ioctl.c:1608
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
       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

-> #0 (&ei->i_data_sem/1){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3098 [inline]
       check_prevs_add kernel/locking/lockdep.c:3217 [inline]
       validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3832
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
       lock_acquire+0x1e1/0x520 kernel/locking/lockdep.c:5669
       down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1689
       ext4_move_extents+0x37d/0xe40 fs/ext4/move_extent.c:620
       __ext4_ioctl fs/ext4/ioctl.c:1352 [inline]
       ext4_ioctl+0x3841/0x5b30 fs/ext4/ioctl.c:1608
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
       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

other info that might help us debug this:

Chain exists of:
  &ei->i_data_sem/1 --> &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(&ei->i_data_sem/1);

 *** DEADLOCK ***

4 locks held by syz-executor.3/8908:
 #0: ffff88814b37e460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x1f0 fs/namespace.c:438
 #1: ffff88803cb8c030 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff88803cb8c030 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: lock_two_nondirectories+0xe2/0x140 fs/inode.c:1122
 #2: ffff888074f72c20 (&sb->s_type->i_mutex_key#7/4){+.+.}-{3:3}, at: ext4_move_extents+0x362/0xe40 fs/ext4/move_extent.c:613
 #3: ffff88803cb8beb8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_double_down_write_data_sem+0x2c/0x50

stack backtrace:
CPU: 1 PID: 8908 Comm: syz-executor.3 Not tainted 6.3.0-rc3-syzkaller-00338-gda8e7da11e4b #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
 check_noncircular+0x2fe/0x3b0 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3098 [inline]
 check_prevs_add kernel/locking/lockdep.c:3217 [inline]
 validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3832
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
 lock_acquire+0x1e1/0x520 kernel/locking/lockdep.c:5669
 down_write_nested+0x3d/0x50 kernel/locking/rwsem.c:1689
 ext4_move_extents+0x37d/0xe40 fs/ext4/move_extent.c:620
 __ext4_ioctl fs/ext4/ioctl.c:1352 [inline]
 ext4_ioctl+0x3841/0x5b30 fs/ext4/ioctl.c:1608
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 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: 0033:0x7fd721e8c0f9
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:00007fd722c57168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd721fabf80 RCX: 00007fd721e8c0f9
RDX: 0000000020000040 RSI: 00000000c028660f RDI: 0000000000000003
RBP: 00007fd721ee7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcfb4b57cf R14: 00007fd722c57300 R15: 0000000000022000
 </TASK>

Crashes (95):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-fs 2023/03/26 13:16 upstream da8e7da11e4b fbf0499a .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/26 11:27 upstream da8e7da11e4b fbf0499a .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/26 00:48 upstream da8e7da11e4b fbf0499a .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/25 10:58 upstream 65aca32efdcb fbf0499a .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci-upstream-kasan-gce-root 2023/03/24 14:04 upstream 1e760fa3596e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/24 09:47 upstream 1e760fa3596e f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/23 11:40 upstream fff5a5e7f528 f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/22 17:26 upstream a1effab7a3a3 f94b4a29 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/21 09:37 upstream 17214b70a159 7939252e .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/21 03:09 upstream 7d31677bb7b1 7939252e .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/20 13:10 upstream e8d018dd0257 7939252e .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/20 00:18 upstream e8d018dd0257 7939252e .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/18 08:20 upstream 478a351ce0d6 7939252e .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/17 18:29 upstream 38e04b3e4240 7939252e .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/17 16:46 upstream 0ddc84d2dd43 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/17 13:23 upstream 0ddc84d2dd43 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/16 20:06 upstream 0ddc84d2dd43 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/16 16:13 upstream 9c1bec9c0b08 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/16 09:26 upstream 9c1bec9c0b08 18b58603 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/12 18:15 upstream 134231664868 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/06 06:47 upstream f915322fe014 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/05 16:39 upstream b01fe98d34f3 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/04 09:24 upstream 0a3f9a6b0265 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/03 17:44 upstream 2eb29d59ddf0 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/03/01 09:03 upstream c0927a7a5391 ef65e6cb .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/28 08:40 upstream 982818426a0f 95aee97a .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/27 19:00 upstream f3a2439f20d9 9189cb53 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/27 00:35 upstream f3a2439f20d9 ee50e71c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/26 10:23 upstream 2fcd07b7ccd5 ee50e71c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/25 14:24 upstream 8cbd92339db0 ee50e71c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/25 02:44 upstream 8cbd92339db0 ee50e71c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci-upstream-kasan-gce-selinux-root 2023/02/23 12:39 upstream d8ca6dbb8de7 9e2ebb3c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci-upstream-kasan-gce-selinux-root 2023/02/22 16:17 upstream 5b7c4cabbb65 409945bc .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/22 08:26 upstream 9e58df973d22 42a4d508 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/22 02:28 upstream 9e58df973d22 42a4d508 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/21 23:39 upstream 9e58df973d22 42a4d508 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/16 21:27 upstream 033c40a89f55 38b317a7 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/16 10:35 upstream 033c40a89f55 38b317a7 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/11 08:38 upstream 420b2d431d18 93e26d60 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/02/01 23:25 upstream c0b67534c95c 9a6f477c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/01/29 13:23 upstream c96618275234 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/01/26 02:22 upstream 7c46948a6e9c 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci-upstream-kasan-gce-root 2023/01/25 15:10 upstream 948ef7bb70c4 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci-upstream-kasan-gce-root 2023/01/23 13:18 upstream 2475bf0250de 44388686 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/01/21 13:16 upstream edc00350d205 cc0f9968 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/01/16 13:04 upstream 5dc4c995db9e a63719e7 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2023/01/16 02:47 upstream 5dc4c995db9e a63719e7 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci-upstream-kasan-gce-root 2023/01/15 06:08 upstream 7c6984405241 a63719e7 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci-upstream-kasan-gce-smack-root 2023/01/12 11:20 upstream e8f60cd7db24 96166539 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci2-upstream-fs 2022/11/05 13:25 upstream 64c3dd0b98f5 6d752409 .config console log report info [disk image] [vmlinux] [kernel image] possible deadlock in ext4_move_extents
ci-qemu-upstream-386 2023/03/19 12:08 upstream a3671bd86a97 7939252e .config console log report info possible deadlock in ext4_move_extents
* Struck through repros no longer work on HEAD.