possible deadlock in __configfs_open_file (2)

Status: upstream: reported on 2026/07/30 01:47
Subsystems: integrity lsm fs
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+c87014f645f2fd24312e@syzkaller.appspotmail.com
First crash: 56d, last: 4d12h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
f325ea4d assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ possible deadlock in __configfs_open_file (2) 2026/07/28 01:12 2026/07/28 01:12 2026/07/28 01:56 4cb2b096
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [fs?] possible deadlock in __configfs_open_file (2) 0 (1) 2026/07/30 01:47
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in __configfs_open_file 4 syz 2 18d 46d 0/3 upstream: reported syz repro on 2026/08/04 15:47
upstream possible deadlock in __configfs_open_file fs 4 syz, C 29 219d 637d 29/29 fixed on 2026/05/06 16:40

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
syz.1.616/7816 is trying to acquire lock:
ffff888074bb9970 (&p->frag_sem){.+.+}-{4:4}, at: __configfs_open_file+0xe8/0x9c0 fs/configfs/file.c:304

but task is already holding lock:
ffff88807b6ea690 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
       process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319
       ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
       security_file_post_open+0xc4/0x210 security/security.c:2755
       do_open fs/namei.c:4839 [inline]
       path_openat+0x5cd/0x2440 fs/namei.c:5000
       do_file_open+0x20e/0x430 fs/namei.c:5029
       do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
       do_sys_open fs/open.c:1423 [inline]
       __do_sys_openat fs/open.c:1439 [inline]
       __se_sys_openat fs/open.c:1434 [inline]
       __x64_sys_openat+0x12d/0x210 fs/open.c:1434
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (sb_writers#6){.+.+}-{0:0}:
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
       percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
       percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
       __sb_start_write include/linux/fs/super.h:19 [inline]
       sb_start_write include/linux/fs/super.h:125 [inline]
       mnt_want_write+0x6f/0x420 fs/namespace.c:494
       lookup_open+0x150/0x1990 fs/namei.c:4451
       open_last_lookups fs/namei.c:4767 [inline]
       path_openat+0xa2c/0x2440 fs/namei.c:4997
       do_file_open+0x20e/0x430 fs/namei.c:5029
       file_open_name+0x1c3/0x3e0 fs/open.c:1375
       filp_open+0x2e/0x50 fs/open.c:1392
       nvmet_file_ns_enable+0x95/0x420 drivers/nvme/target/io-cmd-file.c:41
       nvmet_ns_enable+0x43b/0x650 drivers/nvme/target/core.c:601
       nvmet_ns_enable_store+0x11e/0x160 drivers/nvme/target/configfs.c:737
       flush_write_buffer fs/configfs/file.c:207 [inline]
       configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x6af/0x1050 fs/read_write.c:687
       ksys_write+0x12a/0x250 fs/read_write.c:739
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&subsys->lock){+.+.}-{4:4}:
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x1a4/0x1bd0 kernel/locking/mutex.c:821
       nvmet_ns_device_path_store+0x57/0x1c0 drivers/nvme/target/configfs.c:538
       flush_write_buffer fs/configfs/file.c:207 [inline]
       configfs_write_iter+0x302/0x4e0 fs/configfs/file.c:229
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x6af/0x1050 fs/read_write.c:687
       ksys_write+0x12a/0x250 fs/read_write.c:739
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&p->frag_sem){.+.+}-{4:4}:
       check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288
       lock_acquire kernel/locking/lockdep.c:5942 [inline]
       lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
       down_read+0x99/0x4c0 kernel/locking/rwsem.c:1574
       __configfs_open_file+0xe8/0x9c0 fs/configfs/file.c:304
       do_dentry_open+0x6ab/0x14d0 fs/open.c:996
       vfs_open+0x82/0x3f0 fs/open.c:1101
       dentry_open+0x71/0xd0 fs/open.c:1124
       ima_calc_file_hash+0xe1/0x380 security/integrity/ima/ima_crypto.c:269
       ima_collect_measurement+0x94f/0xb30 security/integrity/ima/ima_api.c:300
       process_measurement+0xdfe/0x2350 security/integrity/ima/ima_main.c:425
       ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
       security_file_post_open+0xc4/0x210 security/security.c:2755
       do_open fs/namei.c:4839 [inline]
       path_openat+0x5cd/0x2440 fs/namei.c:5000
       do_file_open+0x20e/0x430 fs/namei.c:5029
       do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
       do_sys_open fs/open.c:1423 [inline]
       __do_sys_openat fs/open.c:1439 [inline]
       __se_sys_openat fs/open.c:1434 [inline]
       __x64_sys_openat+0x12d/0x210 fs/open.c:1434
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  &p->frag_sem --> sb_writers#6 --> &ima_iint_mutex_key[depth]

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ima_iint_mutex_key[depth]);
                               lock(sb_writers#6);
                               lock(&ima_iint_mutex_key[depth]);
  rlock(&p->frag_sem);

 *** DEADLOCK ***

locks held by syz.1.616/7816: 1, last CPU#1:
 #0: ffff88807b6ea690 (&ima_iint_mutex_key[depth]){+.+.}-{4:4}, at: process_measurement+0x5ab/0x2350 security/integrity/ima/ima_main.c:319

stack backtrace:
CPU: 1 UID: 0 PID: 7816 Comm: syz.1.616 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_circular_bug.cold+0x178/0x1be kernel/locking/lockdep.c:2087
 check_noncircular+0x146/0x160 kernel/locking/lockdep.c:2219
 check_prev_add+0xeb/0xe60 kernel/locking/lockdep.c:3209
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x1528/0x1f40 kernel/locking/lockdep.c:5288
 lock_acquire kernel/locking/lockdep.c:5942 [inline]
 lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
 down_read+0x99/0x4c0 kernel/locking/rwsem.c:1574
 __configfs_open_file+0xe8/0x9c0 fs/configfs/file.c:304
 do_dentry_open+0x6ab/0x14d0 fs/open.c:996
 vfs_open+0x82/0x3f0 fs/open.c:1101
 dentry_open+0x71/0xd0 fs/open.c:1124
 ima_calc_file_hash+0xe1/0x380 security/integrity/ima/ima_crypto.c:269
 ima_collect_measurement+0x94f/0xb30 security/integrity/ima/ima_api.c:300
 process_measurement+0xdfe/0x2350 security/integrity/ima/ima_main.c:425
 ima_file_check+0xc3/0x110 security/integrity/ima/ima_main.c:685
 security_file_post_open+0xc4/0x210 security/security.c:2755
 do_open fs/namei.c:4839 [inline]
 path_openat+0x5cd/0x2440 fs/namei.c:5000
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0x12d/0x210 fs/open.c:1434
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc71f9e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbc72e9c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbc72225fa0 RCX: 00007fbc71f9e159
RDX: 0000000000080183 RSI: 0000200000000300 RDI: ffffffffffffff9c
RBP: 00007fbc7203503b R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000002c R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbc72226038 R14: 00007fbc72225fa0 R15: 00007ffd73faf0d8
 </TASK>

Crashes (28):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/15 01:51 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in __configfs_open_file
2026/09/15 01:33 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root possible deadlock in __configfs_open_file
2026/09/15 01:33 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root possible deadlock in __configfs_open_file
2026/09/10 05:46 upstream 50d05c7c76c9 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root possible deadlock in __configfs_open_file
2026/09/14 20:24 upstream 704340f1cd0d 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __configfs_open_file
2026/09/10 13:54 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __configfs_open_file
2026/09/10 09:39 upstream 50d05c7c76c9 4e8b1cc6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __configfs_open_file
2026/09/08 14:14 upstream 28924df2a08f 351387c4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __configfs_open_file
2026/09/08 02:04 upstream 28924df2a08f 680aa3e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __configfs_open_file
2026/09/02 10:01 upstream 89a312991dc6 587f6b29 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __configfs_open_file
2026/08/23 19:05 upstream 818bebeb63dd 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __configfs_open_file
2026/07/26 01:37 upstream 3dab139d4795 4a865b71 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream possible deadlock in __configfs_open_file
2026/09/16 03:00 upstream 50d05c7c76c9 12a0a44a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/15 14:06 upstream 50d05c7c76c9 f41e228a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/15 14:06 upstream 50d05c7c76c9 f41e228a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/15 14:06 upstream 50d05c7c76c9 f41e228a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/15 09:11 upstream 50d05c7c76c9 81a27d1a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/14 12:57 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/14 12:57 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/14 12:57 upstream 50d05c7c76c9 924033e8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/13 18:48 upstream 50d05c7c76c9 70a60e12 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/10 12:23 upstream 50d05c7c76c9 1fe56c0a .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/10 00:45 upstream 50d05c7c76c9 4e8b1cc6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/10 00:45 upstream 50d05c7c76c9 4e8b1cc6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/10 00:44 upstream 50d05c7c76c9 4e8b1cc6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/06 18:04 upstream 1fc5a74b108f 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/06 04:17 upstream 9f0346dcbea3 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
2026/09/06 04:16 upstream 9f0346dcbea3 4f7b22a0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __configfs_open_file
* Struck through repros no longer work on HEAD.