syzbot


possible deadlock in ext4_xattr_set_handle (6)

Status: upstream: reported on 2024/10/02 09:48
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+f5fadcee2108d2f0dd2d@syzkaller.appspotmail.com
First crash: 6d14h, last: 1d18h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ext4?] possible deadlock in ext4_xattr_set_handle (6) 0 (1) 2024/10/02 09:48
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in ext4_xattr_set_handle (5) ext4 72 101d 144d 0/28 auto-obsoleted due to no activity on 2024/09/03 19:27
upstream possible deadlock in ext4_xattr_set_handle (3) ext4 C 451 461d 619d 22/28 fixed on 2023/07/01 16:05
upstream possible deadlock in ext4_xattr_set_handle (4) ext4 5 258d 378d 0/28 auto-obsoleted due to no activity on 2024/04/29 16:11
upstream possible deadlock in ext4_xattr_set_handle ext4 1 1082d 1078d 0/28 auto-closed as invalid on 2022/02/15 19:59
upstream possible deadlock in ext4_xattr_set_handle (2) ext4 1 816d 815d 0/28 auto-obsoleted due to no activity on 2022/11/08 16:24
linux-5.15 possible deadlock in ext4_xattr_set_handle C done 42 484d 577d 3/3 fixed on 2023/07/17 13:09
linux-4.19 possible deadlock in ext4_xattr_set_handle ext4 1 609d 609d 0/1 upstream: reported on 2023/02/03 16:43
linux-6.1 possible deadlock in ext4_xattr_set_handle C done 15 485d 572d 3/3 fixed on 2023/07/17 13:09

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc1-syzkaller-00042-gf23aa4c0761a #0 Not tainted
------------------------------------------------------
syz.2.2715/23336 is trying to acquire lock:
ffff88807744e3d8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:154 [inline]
ffff88807744e3d8 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_set_handle+0x277/0x1580 fs/ext4/xattr.c:2373

but task is already holding lock:
ffff88807d12e958 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1e94/0x2110 fs/jbd2/transaction.c:448

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #5 (jbd2_handle){++++}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       start_this_handle+0x1eb4/0x2110 fs/jbd2/transaction.c:448
       jbd2__journal_start+0x2da/0x5d0 fs/jbd2/transaction.c:505
       jbd2_journal_start+0x29/0x40 fs/jbd2/transaction.c:544
       ocfs2_start_trans+0x3c9/0x700 fs/ocfs2/journal.c:352
       ocfs2_mknod+0x150c/0x2b40 fs/ocfs2/namei.c:359
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x1c05/0x3590 fs/namei.c:3930
       do_filp_open+0x235/0x490 fs/namei.c:3960
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_openat fs/open.c:1446 [inline]
       __se_sys_openat fs/open.c:1441 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
       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

-> #4 (&journal->j_trans_barrier){.+.+}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       ocfs2_start_trans+0x3be/0x700 fs/ocfs2/journal.c:350
       ocfs2_mknod+0x150c/0x2b40 fs/ocfs2/namei.c:359
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x1c05/0x3590 fs/namei.c:3930
       do_filp_open+0x235/0x490 fs/namei.c:3960
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_openat fs/open.c:1446 [inline]
       __se_sys_openat fs/open.c:1441 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
       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

-> #3 (sb_internal#5){.+.+}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1716 [inline]
       sb_start_intwrite include/linux/fs.h:1899 [inline]
       ocfs2_start_trans+0x2b9/0x700 fs/ocfs2/journal.c:348
       ocfs2_acquire_dquot+0x6df/0xb80 fs/ocfs2/quota_global.c:855
       dqget+0x772/0xeb0 fs/quota/dquot.c:976
       __dquot_initialize+0x2e3/0xec0 fs/quota/dquot.c:1504
       ocfs2_get_init_inode+0x158/0x1c0 fs/ocfs2/namei.c:202
       ocfs2_mknod+0xcfa/0x2b40 fs/ocfs2/namei.c:308
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x1c05/0x3590 fs/namei.c:3930
       do_filp_open+0x235/0x490 fs/namei.c:3960
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_openat fs/open.c:1446 [inline]
       __se_sys_openat fs/open.c:1441 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
       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

-> #2 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       ocfs2_create_local_dquot+0x1de/0x1d70 fs/ocfs2/quota_local.c:1231
       ocfs2_acquire_dquot+0x833/0xb80 fs/ocfs2/quota_global.c:878
       dqget+0x772/0xeb0 fs/quota/dquot.c:976
       __dquot_initialize+0x2e3/0xec0 fs/quota/dquot.c:1504
       ocfs2_get_init_inode+0x158/0x1c0 fs/ocfs2/namei.c:202
       ocfs2_mknod+0xcfa/0x2b40 fs/ocfs2/namei.c:308
       ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
       lookup_open fs/namei.c:3595 [inline]
       open_last_lookups fs/namei.c:3694 [inline]
       path_openat+0x1c05/0x3590 fs/namei.c:3930
       do_filp_open+0x235/0x490 fs/namei.c:3960
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
       do_sys_open fs/open.c:1430 [inline]
       __do_sys_openat fs/open.c:1446 [inline]
       __se_sys_openat fs/open.c:1441 [inline]
       __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
       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

-> #1 (&dquot->dq_lock){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       wait_on_dquot fs/quota/dquot.c:355 [inline]
       dqget+0x6e6/0xeb0 fs/quota/dquot.c:971
       dquot_transfer+0x482/0x6d0 fs/quota/dquot.c:2153
       ext4_setattr+0xaf3/0x1bc0 fs/ext4/inode.c:5368
       notify_change+0xbcc/0xe90 fs/attr.c:503
       chown_common+0x501/0x850 fs/open.c:793
       do_fchownat+0x16a/0x240 fs/open.c:824
       __do_sys_lchown fs/open.c:849 [inline]
       __se_sys_lchown fs/open.c:847 [inline]
       __x64_sys_lchown+0x85/0xa0 fs/open.c:847
       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

-> #0 (&ei->xattr_sem){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
       down_write+0x99/0x220 kernel/locking/rwsem.c:1577
       ext4_write_lock_xattr fs/ext4/xattr.h:154 [inline]
       ext4_xattr_set_handle+0x277/0x1580 fs/ext4/xattr.c:2373
       ext4_xattr_set+0x241/0x3d0 fs/ext4/xattr.c:2560
       __vfs_setxattr+0x46a/0x4a0 fs/xattr.c:200
       __vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234
       vfs_setxattr+0x221/0x430 fs/xattr.c:321
       do_setxattr fs/xattr.c:629 [inline]
       __do_sys_fsetxattr fs/xattr.c:710 [inline]
       __se_sys_fsetxattr+0x383/0x480 fs/xattr.c:686
       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

other info that might help us debug this:

Chain exists of:
  &ei->xattr_sem --> &journal->j_trans_barrier --> jbd2_handle

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(jbd2_handle);
                               lock(&journal->j_trans_barrier);
                               lock(jbd2_handle);
  lock(&ei->xattr_sem);

 *** DEADLOCK ***

3 locks held by syz.2.2715/23336:
 #0: ffff88807d12a420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
 #1: ffff88807744e708 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #1: ffff88807744e708 (&sb->s_type->i_mutex_key#8){++++}-{3:3}, at: vfs_setxattr+0x1e1/0x430 fs/xattr.c:320
 #2: ffff88807d12e958 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1e94/0x2110 fs/jbd2/transaction.c:448

stack backtrace:
CPU: 1 UID: 0 PID: 23336 Comm: syz.2.2715 Not tainted 6.12.0-rc1-syzkaller-00042-gf23aa4c0761a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 down_write+0x99/0x220 kernel/locking/rwsem.c:1577
 ext4_write_lock_xattr fs/ext4/xattr.h:154 [inline]
 ext4_xattr_set_handle+0x277/0x1580 fs/ext4/xattr.c:2373
 ext4_xattr_set+0x241/0x3d0 fs/ext4/xattr.c:2560
 __vfs_setxattr+0x46a/0x4a0 fs/xattr.c:200
 __vfs_setxattr_noperm+0x12e/0x660 fs/xattr.c:234
 vfs_setxattr+0x221/0x430 fs/xattr.c:321
 do_setxattr fs/xattr.c:629 [inline]
 __do_sys_fsetxattr fs/xattr.c:710 [inline]
 __se_sys_fsetxattr+0x383/0x480 fs/xattr.c:686
 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: 0033:0x7f05b717dff9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f05b7fcf038 EFLAGS: 00000246 ORIG_RAX: 00000000000000be
RAX: ffffffffffffffda RBX: 00007f05b7335f80 RCX: 00007f05b717dff9
RDX: 0000000020000180 RSI: 0000000020000040 RDI: 000000000000000a
RBP: 00007f05b71f0296 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000014 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f05b7335f80 R15: 00007ffc0ab4ff08
 </TASK>

Crashes (14):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/03 05:41 upstream f23aa4c0761a a4c7fd36 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/10/03 05:08 upstream f23aa4c0761a a4c7fd36 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/10/03 05:07 upstream f23aa4c0761a a4c7fd36 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/10/02 03:15 upstream e32cde8d2bd7 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in ext4_xattr_set_handle
2024/10/01 16:39 upstream e32cde8d2bd7 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/10/01 16:39 upstream e32cde8d2bd7 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/10/01 05:43 upstream e32cde8d2bd7 bbd4e0a4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/09/30 23:09 upstream 9852d85ec9d4 bbd4e0a4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in ext4_xattr_set_handle
2024/09/30 02:51 upstream e7ed34365879 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/09/28 09:38 upstream ad46e8f95e93 440b26ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/10/02 20:13 linux-next fe2173353674 a4c7fd36 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/09/30 12:17 linux-next cea5425829f7 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/09/29 07:14 linux-next 40e0c9d414f5 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ext4_xattr_set_handle
2024/09/28 15:40 linux-next 40e0c9d414f5 440b26ec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in ext4_xattr_set_handle
* Struck through repros no longer work on HEAD.