syzbot


possible deadlock in __ext4_mark_inode_dirty

Status: auto-obsoleted due to no activity on 2023/07/23 20:58
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+9fcd24c261324f545b8a@syzkaller.appspotmail.com
First crash: 413d, last: 385d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ext4?] possible deadlock in __ext4_mark_inode_dirty 0 (1) 2023/03/02 13:48
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in __ext4_mark_inode_dirty (3) ext4 1 31d 27d 0/26 upstream: reported on 2024/03/18 03:33
upstream possible deadlock in __ext4_mark_inode_dirty (2) ext4 4 165d 244d 0/26 auto-obsoleted due to no activity on 2024/02/09 09:55

Sample crash report:
WARNING: possible circular locking dependency detected
6.3.0-rc2-syzkaller-00363-g478a351ce0d6 #0 Not tainted
------------------------------------------------------
syz-executor.0/7268 is trying to acquire lock:
ffffffff8c8e1280 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:271 [inline]
ffffffff8c8e1280 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slab.h:728 [inline]
ffffffff8c8e1280 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slab.c:3241 [inline]
ffffffff8c8e1280 (fs_reclaim){+.+.}-{0:0}, at: __kmem_cache_alloc_node+0x3b/0x3f0 mm/slab.c:3541

but task is already holding lock:
ffff88802935d188 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
ffff88802935d188 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6000 [inline]
ffff88802935d188 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x48f/0x800 fs/ext4/inode.c:6081

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&ei->xattr_sem){++++}-{3:3}:
       down_write+0x92/0x200 kernel/locking/rwsem.c:1573
       ext4_write_lock_xattr fs/ext4/xattr.h:155 [inline]
       ext4_xattr_set_handle+0x160/0x1510 fs/ext4/xattr.c:2373
       ext4_initxattrs+0xb9/0x120 fs/ext4/xattr_security.c:44
       security_inode_init_security+0x1c8/0x370 security/security.c:1147
       __ext4_new_inode+0x4485/0x54c0 fs/ext4/ialloc.c:1324
       ext4_create+0x2da/0x4e0 fs/ext4/namei.c:2808
       lookup_open.isra.0+0x105a/0x1400 fs/namei.c:3416
       open_last_lookups fs/namei.c:3484 [inline]
       path_openat+0x975/0x2750 fs/namei.c:3712
       do_filp_open+0x1ba/0x410 fs/namei.c:3742
       do_sys_openat2+0x16d/0x4c0 fs/open.c:1348
       do_sys_open fs/open.c:1364 [inline]
       __do_sys_openat fs/open.c:1380 [inline]
       __se_sys_openat fs/open.c:1375 [inline]
       __x64_sys_openat+0x143/0x1f0 fs/open.c:1375
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #2 (jbd2_handle){++++}-{0:0}:
       start_this_handle+0xfe7/0x14e0 fs/jbd2/transaction.c:463
       jbd2__journal_start+0x390/0x850 fs/jbd2/transaction.c:520
       __ext4_journal_start_sb+0x411/0x5d0 fs/ext4/ext4_jbd2.c:111
       ext4_sample_last_mounted fs/ext4/file.c:851 [inline]
       ext4_file_open+0x618/0xbf0 fs/ext4/file.c:880
       do_dentry_open+0x6cc/0x13f0 fs/open.c:920
       do_open fs/namei.c:3560 [inline]
       path_openat+0x1baa/0x2750 fs/namei.c:3715
       do_filp_open+0x1ba/0x410 fs/namei.c:3742
       do_sys_openat2+0x16d/0x4c0 fs/open.c:1348
       do_sys_open fs/open.c:1364 [inline]
       __do_sys_openat fs/open.c:1380 [inline]
       __se_sys_openat fs/open.c:1375 [inline]
       __x64_sys_openat+0x143/0x1f0 fs/open.c:1375
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (sb_internal){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1477 [inline]
       sb_start_intwrite include/linux/fs.h:1599 [inline]
       ext4_evict_inode+0x114b/0x1ca0 fs/ext4/inode.c:240
       evict+0x2ed/0x6b0 fs/inode.c:665
       iput_final fs/inode.c:1748 [inline]
       iput.part.0+0x50a/0x740 fs/inode.c:1774
       iput+0x5c/0x80 fs/inode.c:1764
       dentry_unlink_inode+0x2b1/0x460 fs/dcache.c:401
       __dentry_kill+0x3c0/0x640 fs/dcache.c:607
       dentry_kill fs/dcache.c:745 [inline]
       dput+0x6ac/0xe10 fs/dcache.c:913
       ovl_entry_stack_free fs/overlayfs/super.c:62 [inline]
       ovl_dentry_release+0xce/0x140 fs/overlayfs/super.c:75
       __dentry_kill+0x42b/0x640 fs/dcache.c:612
       shrink_dentry_list+0x12c/0x4f0 fs/dcache.c:1201
       prune_dcache_sb+0xeb/0x150 fs/dcache.c:1282
       super_cache_scan+0x33a/0x590 fs/super.c:104
       do_shrink_slab+0x428/0xaa0 mm/vmscan.c:853
       shrink_slab_memcg mm/vmscan.c:922 [inline]
       shrink_slab+0x388/0x660 mm/vmscan.c:1001
       shrink_one+0x502/0x810 mm/vmscan.c:5343
       shrink_many mm/vmscan.c:5394 [inline]
       lru_gen_shrink_node mm/vmscan.c:5511 [inline]
       shrink_node+0x2064/0x35f0 mm/vmscan.c:6459
       kswapd_shrink_node mm/vmscan.c:7262 [inline]
       balance_pgdat+0xa02/0x1ac0 mm/vmscan.c:7452
       kswapd+0x677/0xd60 mm/vmscan.c:7712
       kthread+0x2e8/0x3a0 kernel/kthread.c:376
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

-> #0 (fs_reclaim){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3098 [inline]
       check_prevs_add kernel/locking/lockdep.c:3217 [inline]
       validate_chain kernel/locking/lockdep.c:3832 [inline]
       __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056
       lock_acquire kernel/locking/lockdep.c:5669 [inline]
       lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634
       __fs_reclaim_acquire mm/page_alloc.c:4716 [inline]
       fs_reclaim_acquire+0x11d/0x160 mm/page_alloc.c:4730
       might_alloc include/linux/sched/mm.h:271 [inline]
       slab_pre_alloc_hook mm/slab.h:728 [inline]
       slab_alloc_node mm/slab.c:3241 [inline]
       __kmem_cache_alloc_node+0x3b/0x3f0 mm/slab.c:3541
       __do_kmalloc_node mm/slab_common.c:966 [inline]
       __kmalloc_node+0x51/0x1a0 mm/slab_common.c:974
       kmalloc_node include/linux/slab.h:610 [inline]
       kvmalloc_node+0xa2/0x1a0 mm/util.c:603
       kvmalloc include/linux/slab.h:737 [inline]
       ext4_xattr_inode_cache_find fs/ext4/xattr.c:1552 [inline]
       ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1595 [inline]
       ext4_xattr_set_entry+0x1d82/0x39e0 fs/ext4/xattr.c:1737
       ext4_xattr_block_set+0x618/0x3030 fs/ext4/xattr.c:1974
       ext4_xattr_move_to_block fs/ext4/xattr.c:2668 [inline]
       ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline]
       ext4_expand_extra_isize_ea+0xa84/0x1880 fs/ext4/xattr.c:2835
       __ext4_expand_extra_isize+0x33e/0x470 fs/ext4/inode.c:5960
       ext4_try_to_expand_extra_isize fs/ext4/inode.c:6003 [inline]
       __ext4_mark_inode_dirty+0x51b/0x800 fs/ext4/inode.c:6081
       __ext4_unlink+0x667/0xcd0 fs/ext4/namei.c:3269
       ext4_unlink+0x41f/0x590 fs/ext4/namei.c:3298
       vfs_unlink+0x355/0x930 fs/namei.c:4250
       do_unlinkat+0x3df/0x670 fs/namei.c:4316
       __do_sys_unlinkat fs/namei.c:4359 [inline]
       __se_sys_unlinkat fs/namei.c:4352 [inline]
       __x64_sys_unlinkat+0xc1/0x130 fs/namei.c:4352
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
  fs_reclaim --> jbd2_handle --> &ei->xattr_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->xattr_sem);
                               lock(jbd2_handle);
                               lock(&ei->xattr_sem);
  lock(fs_reclaim);

 *** DEADLOCK ***

4 locks held by syz-executor.0/7268:
 #0: ffff88802b90a460 (sb_writers#5){.+.+}-{0:0}, at: do_unlinkat+0x18c/0x670 fs/namei.c:4297
 #1: ffff888029334740 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline]
 #1: ffff888029334740 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_unlinkat+0x27c/0x670 fs/namei.c:4301
 #2: ffff88802935d4c0 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff88802935d4c0 (&sb->s_type->i_mutex_key#7){++++}-{3:3}, at: vfs_unlink+0xd9/0x930 fs/namei.c:4239
 #3: ffff88802935d188 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:162 [inline]
 #3: ffff88802935d188 (&ei->xattr_sem){++++}-{3:3}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6000 [inline]
 #3: ffff88802935d188 (&ei->xattr_sem){++++}-{3:3}, at: __ext4_mark_inode_dirty+0x48f/0x800 fs/ext4/inode.c:6081

stack backtrace:
CPU: 3 PID: 7268 Comm: syz-executor.0 Not tainted 6.3.0-rc2-syzkaller-00363-g478a351ce0d6 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 check_noncircular+0x25f/0x2e0 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 kernel/locking/lockdep.c:3832 [inline]
 __lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056
 lock_acquire kernel/locking/lockdep.c:5669 [inline]
 lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634
 __fs_reclaim_acquire mm/page_alloc.c:4716 [inline]
 fs_reclaim_acquire+0x11d/0x160 mm/page_alloc.c:4730
 might_alloc include/linux/sched/mm.h:271 [inline]
 slab_pre_alloc_hook mm/slab.h:728 [inline]
 slab_alloc_node mm/slab.c:3241 [inline]
 __kmem_cache_alloc_node+0x3b/0x3f0 mm/slab.c:3541
 __do_kmalloc_node mm/slab_common.c:966 [inline]
 __kmalloc_node+0x51/0x1a0 mm/slab_common.c:974
 kmalloc_node include/linux/slab.h:610 [inline]
 kvmalloc_node+0xa2/0x1a0 mm/util.c:603
 kvmalloc include/linux/slab.h:737 [inline]
 ext4_xattr_inode_cache_find fs/ext4/xattr.c:1552 [inline]
 ext4_xattr_inode_lookup_create fs/ext4/xattr.c:1595 [inline]
 ext4_xattr_set_entry+0x1d82/0x39e0 fs/ext4/xattr.c:1737
 ext4_xattr_block_set+0x618/0x3030 fs/ext4/xattr.c:1974
 ext4_xattr_move_to_block fs/ext4/xattr.c:2668 [inline]
 ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline]
 ext4_expand_extra_isize_ea+0xa84/0x1880 fs/ext4/xattr.c:2835
 __ext4_expand_extra_isize+0x33e/0x470 fs/ext4/inode.c:5960
 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6003 [inline]
 __ext4_mark_inode_dirty+0x51b/0x800 fs/ext4/inode.c:6081
 __ext4_unlink+0x667/0xcd0 fs/ext4/namei.c:3269
 ext4_unlink+0x41f/0x590 fs/ext4/namei.c:3298
 vfs_unlink+0x355/0x930 fs/namei.c:4250
 do_unlinkat+0x3df/0x670 fs/namei.c:4316
 __do_sys_unlinkat fs/namei.c:4359 [inline]
 __se_sys_unlinkat fs/namei.c:4352 [inline]
 __x64_sys_unlinkat+0xc1/0x130 fs/namei.c:4352
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa4ee68c0f9
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:00007fa4ef309168 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007fa4ee7abf80 RCX: 00007fa4ee68c0f9
RDX: 0000000000000000 RSI: 00000000200003c0 RDI: ffffffffffffff9c
RBP: 00007fa4ee6e7b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd7821386f R14: 00007fa4ef309300 R15: 0000000000022000
 </TASK>

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/18 09:19 upstream 478a351ce0d6 7939252e .config console log report info ci-qemu-upstream possible deadlock in __ext4_mark_inode_dirty
2023/03/15 12:06 upstream 6015b1aca1a2 18b58603 .config console log report info ci-qemu-upstream possible deadlock in __ext4_mark_inode_dirty
2023/03/13 13:33 upstream eeac8ede1755 026e2200 .config console log report info ci-qemu-upstream possible deadlock in __ext4_mark_inode_dirty
2023/02/26 13:40 upstream 1ec35eadc3b4 630c6bc9 .config console log report info ci-qemu-upstream possible deadlock in __ext4_mark_inode_dirty
2023/03/25 20:57 upstream 65aca32efdcb fbf0499a .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/24 16:07 upstream 1e760fa3596e ee89d73c .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/22 13:08 upstream a1effab7a3a3 d846e076 .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/22 04:06 upstream 2faac9a98f01 8b4eb097 .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/21 12:43 upstream 17214b70a159 03fb9538 .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/21 01:45 upstream 7d31677bb7b1 7939252e .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/20 22:31 upstream 7d31677bb7b1 7939252e .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/18 14:15 upstream 478a351ce0d6 7939252e .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/14 10:11 upstream fc89d7fb499b 0d5c4377 .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
2023/03/05 05:08 upstream c29214bc8916 f8902b57 .config console log report info ci-qemu-upstream-386 possible deadlock in __ext4_mark_inode_dirty
* Struck through repros no longer work on HEAD.