======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/26456 is trying to acquire lock:
ffff888075cf5980 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x67b/0x1930 security/integrity/ima/ima_main.c:262

but task is already holding lock:
ffff88814b82a460 (sb_writers#4){.+.+}-{0:0}, at: do_open fs/namei.c:3553 [inline]
ffff88814b82a460 (sb_writers#4){.+.+}-{0:0}, at: path_openat+0x19a4/0x2750 fs/namei.c:3715

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sb_writers#4){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1477 [inline]
       sb_start_write include/linux/fs.h:1552 [inline]
       mnt_want_write+0x70/0x420 fs/namespace.c:394
       ovl_maybe_copy_up+0x123/0x190 fs/overlayfs/copy_up.c:1125
       ovl_open+0xf5/0x2e0 fs/overlayfs/file.c:153
       do_dentry_open+0x6cc/0x13f0 fs/open.c:920
       vfs_open fs/open.c:1051 [inline]
       dentry_open+0x136/0x1d0 fs/open.c:1067
       ima_calc_file_hash+0x2ca/0x4a0 security/integrity/ima/ima_crypto.c:558
       ima_collect_measurement+0x55b/0x670 security/integrity/ima/ima_api.c:293
       process_measurement+0xd2f/0x1930 security/integrity/ima/ima_main.c:341
       ima_file_check+0xba/0x100 security/integrity/ima/ima_main.c:539
       do_open fs/namei.c:3562 [inline]
       path_openat+0x15d3/0x2750 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_open fs/open.c:1372 [inline]
       __se_sys_open fs/open.c:1368 [inline]
       __x64_sys_open+0x11d/0x1c0 fs/open.c:1368
       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

-> #0 (&iint->mutex){+.+.}-{3:3}:
       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
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747
       process_measurement+0x67b/0x1930 security/integrity/ima/ima_main.c:262
       ima_file_check+0xba/0x100 security/integrity/ima/ima_main.c:539
       do_open fs/namei.c:3562 [inline]
       path_openat+0x15d3/0x2750 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_open fs/open.c:1372 [inline]
       __se_sys_open fs/open.c:1368 [inline]
       __x64_sys_open+0x11d/0x1c0 fs/open.c:1368
       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:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_writers#4);
                               lock(&iint->mutex);
                               lock(sb_writers#4);
  lock(&iint->mutex);

 *** DEADLOCK ***

1 lock held by syz-executor.0/26456:
 #0: ffff88814b82a460 (sb_writers#4){.+.+}-{0:0}, at: do_open fs/namei.c:3553 [inline]
 #0: ffff88814b82a460 (sb_writers#4){.+.+}-{0:0}, at: path_openat+0x19a4/0x2750 fs/namei.c:3715

stack backtrace:
CPU: 0 PID: 26456 Comm: syz-executor.0 Not tainted 6.3.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
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
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747
 process_measurement+0x67b/0x1930 security/integrity/ima/ima_main.c:262
 ima_file_check+0xba/0x100 security/integrity/ima/ima_main.c:539
 do_open fs/namei.c:3562 [inline]
 path_openat+0x15d3/0x2750 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_open fs/open.c:1372 [inline]
 __se_sys_open fs/open.c:1368 [inline]
 __x64_sys_open+0x11d/0x1c0 fs/open.c:1368
 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: 0033:0x7f1c88a8c169
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:00007f1c875dd168 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f1c88bac050 RCX: 00007f1c88a8c169
RDX: 0000000000000050 RSI: 0000000000000200 RDI: 0000000020000080
RBP: 00007f1c88ae7ca1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff66aba09f R14: 00007f1c875dd300 R15: 0000000000022000
 </TASK>