possible deadlock in process_measurement

Status: upstream: reported on 2026/08/10 07:52
Reported-by: syzbot+e9278746ae9abcd52896@syzkaller.appspotmail.com
First crash: 16h16m, last: 16h16m
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in process_measurement (5) integrity lsm 4 49 316d 452d 0/29 auto-obsoleted due to no activity on 2025/12/07 20:43
linux-5.15 possible deadlock in process_measurement (2) 4 3 2h22m 6d08h 0/3 upstream: reported on 2026/08/04 15:46
upstream possible deadlock in process_measurement (4) integrity lsm 4 syz, C done 7976 644d 681d 28/29 fixed on 2024/11/14 10:09
upstream possible deadlock in process_measurement (2) integrity lsm 4 syz, C done done 56 2076d 2443d 15/29 fixed on 2021/01/06 01:14
upstream possible deadlock in process_measurement (3) overlayfs 4 syz, C error 223 1012d 1918d 0/29 closed as dup on 2023/06/06 09:59
upstream possible deadlock in process_measurement (6) integrity lsm prio:low 4 284 2h54m 11d 0/29 upstream: reported on 2026/07/30 00:19
linux-4.19 possible deadlock in process_measurement 4 156 1427d 2399d 0/1 auto-obsoleted due to no activity on 2023/01/11 22:20
upstream possible deadlock in process_measurement integrity lsm 4 syz, C 51 2623d 2856d 0/29 closed as invalid on 2019/07/15 16:35
linux-6.1 possible deadlock in process_measurement origin:lts-only 4 syz, C unreliable 4194 20h58m 1073d 0/3 upstream: reported C repro on 2023/09/02 00:54
linux-5.15 possible deadlock in process_measurement origin:lts-only 4 syz, C done 4 996d 1071d 0/3 auto-obsoleted due to no activity on 2024/10/03 14:31

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.1236/11503 is trying to acquire lock:
ffff888069237770 (&iint_mutex_key[depth]){+.+.}-{3:3}, at: process_measurement+0x739/0x1d50 security/integrity/ima/ima_main.c:275

but task is already holding lock:
ffff88806b6df070 (&subsys->lock){+.+.}-{3:3}, at: nvmet_ns_enable+0x4d/0x8c0 drivers/nvme/target/core.c:561

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&subsys->lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
       nvmet_ns_device_path_store+0x54/0x150 drivers/nvme/target/configfs.c:350
       flush_write_buffer fs/configfs/file.c:207 [inline]
       configfs_write_iter+0x312/0x400 fs/configfs/file.c:229
       call_write_iter include/linux/fs.h:2018 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x474/0x9a0 fs/read_write.c:584
       ksys_write+0x151/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&p->frag_sem){.+.+}-{3:3}:
       down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520
       __configfs_open_file+0xd8/0x7d0 fs/configfs/file.c:304
       do_dentry_open+0x880/0x14b0 fs/open.c:929
       vfs_open fs/open.c:1065 [inline]
       dentry_open+0xbb/0x100 fs/open.c:1079
       ima_calc_file_hash+0x190/0x1960 security/integrity/ima/ima_crypto.c:558
       ima_collect_measurement+0x4d4/0xa30 security/integrity/ima/ima_api.c:290
       process_measurement+0x123a/0x1d50 security/integrity/ima/ima_main.c:370
       ima_file_check+0xcc/0x110 security/integrity/ima/ima_main.c:568
       do_open fs/namei.c:3685 [inline]
       path_openat+0x2910/0x3270 fs/namei.c:3844
       do_filp_open+0x1f2/0x430 fs/namei.c:3871
       do_sys_openat2+0x134/0x1d0 fs/open.c:1422
       do_sys_open fs/open.c:1437 [inline]
       __do_sys_openat fs/open.c:1453 [inline]
       __se_sys_openat fs/open.c:1448 [inline]
       __x64_sys_openat+0x139/0x160 fs/open.c:1448
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&iint_mutex_key[depth]){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
       process_measurement+0x739/0x1d50 security/integrity/ima/ima_main.c:275
       ima_file_check+0xcc/0x110 security/integrity/ima/ima_main.c:568
       do_open fs/namei.c:3685 [inline]
       path_openat+0x2910/0x3270 fs/namei.c:3844
       do_filp_open+0x1f2/0x430 fs/namei.c:3871
       file_open_name fs/open.c:1367 [inline]
       filp_open+0x180/0x1e0 fs/open.c:1387
       nvmet_file_ns_enable+0x74/0x330 drivers/nvme/target/io-cmd-file.c:41
       nvmet_ns_enable+0xf4/0x8c0 drivers/nvme/target/core.c:578
       nvmet_ns_enable_store+0xd8/0x170 drivers/nvme/target/configfs.c:549
       flush_write_buffer fs/configfs/file.c:207 [inline]
       configfs_write_iter+0x312/0x400 fs/configfs/file.c:229
       call_write_iter include/linux/fs.h:2018 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x474/0x9a0 fs/read_write.c:584
       ksys_write+0x151/0x260 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &iint_mutex_key[depth] --> &p->frag_sem --> &subsys->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&subsys->lock);
                               lock(&p->frag_sem);
                               lock(&subsys->lock);
  lock(&iint_mutex_key[depth]);

 *** DEADLOCK ***

6 locks held by syz.1.1236/11503:
 #0: ffff8880288240c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
 #1: ffff888018be0418 (sb_writers#18){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
 #2: ffff88802df14c88 (&buffer->mutex#2){+.+.}-{3:3}, at: configfs_write_iter+0x81/0x400 fs/configfs/file.c:226
 #3: ffff888065562d78 (&p->frag_sem){.+.+}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
 #3: ffff888065562d78 (&p->frag_sem){.+.+}-{3:3}, at: configfs_write_iter+0x215/0x400 fs/configfs/file.c:229
 #4: ffffffff8daee6d0 (nvmet_config_sem){+.+.}-{3:3}, at: nvmet_ns_enable_store+0xc9/0x170 drivers/nvme/target/configfs.c:547
 #5: ffff88806b6df070 (&subsys->lock){+.+.}-{3:3}, at: nvmet_ns_enable+0x4d/0x8c0 drivers/nvme/target/core.c:561

stack backtrace:
CPU: 1 PID: 11503 Comm: syz.1.1236 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x135/0xc80 kernel/locking/mutex.c:747
 process_measurement+0x739/0x1d50 security/integrity/ima/ima_main.c:275
 ima_file_check+0xcc/0x110 security/integrity/ima/ima_main.c:568
 do_open fs/namei.c:3685 [inline]
 path_openat+0x2910/0x3270 fs/namei.c:3844
 do_filp_open+0x1f2/0x430 fs/namei.c:3871
 file_open_name fs/open.c:1367 [inline]
 filp_open+0x180/0x1e0 fs/open.c:1387
 nvmet_file_ns_enable+0x74/0x330 drivers/nvme/target/io-cmd-file.c:41
 nvmet_ns_enable+0xf4/0x8c0 drivers/nvme/target/core.c:578
 nvmet_ns_enable_store+0xd8/0x170 drivers/nvme/target/configfs.c:549
 flush_write_buffer fs/configfs/file.c:207 [inline]
 configfs_write_iter+0x312/0x400 fs/configfs/file.c:229
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x474/0x9a0 fs/read_write.c:584
 ksys_write+0x151/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f95d179e0d9
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:00007f95d259b028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f95d1a25fa0 RCX: 00007f95d179e0d9
RDX: 0000000000000001 RSI: 0000200000000580 RDI: 0000000000000008
RBP: 00007f95d1835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f95d1a26038 R14: 00007f95d1a25fa0 R15: 00007ffef3291448
 </TASK>
nvme nvme0: creating 2 I/O queues.
nvme nvme0: new ctrl: "testnqn"

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/10 07:52 linux-6.6.y d27334b2888c 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan possible deadlock in process_measurement
* Struck through repros no longer work on HEAD.