======================================================
WARNING: possible circular locking dependency detected
6.4.0-next-20230707-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/6616 is trying to acquire lock:
ffff8880668a4aa0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x678/0x1940 security/integrity/ima/ima_main.c:266

but task is already holding lock:
ffff88814c4b4410 (sb_writers#4){.+.+}-{0:0}, at: do_open fs/namei.c:3629 [inline]
ffff88814c4b4410 (sb_writers#4){.+.+}-{0:0}, at: path_openat+0x1959/0x2710 fs/namei.c:3793

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:1494 [inline]
       sb_start_write include/linux/fs.h:1569 [inline]
       mnt_want_write+0x70/0x420 fs/namespace.c:403
       ovl_maybe_copy_up+0x123/0x190 fs/overlayfs/copy_up.c:1175
       ovl_open+0x15b/0x330 fs/overlayfs/file.c:167
       do_dentry_open+0x6ce/0x17b0 fs/open.c:914
       vfs_open fs/open.c:1048 [inline]
       dentry_open+0x13f/0x1d0 fs/open.c:1064
       ima_calc_file_hash+0x2d0/0x4b0 security/integrity/ima/ima_crypto.c:558
       ima_collect_measurement+0x5a8/0x6b0 security/integrity/ima/ima_api.c:289
       process_measurement+0xd32/0x1940 security/integrity/ima/ima_main.c:345
       ima_file_check+0xba/0x100 security/integrity/ima/ima_main.c:543
       do_open fs/namei.c:3638 [inline]
       path_openat+0x1588/0x2710 fs/namei.c:3793
       do_filp_open+0x1ba/0x410 fs/namei.c:3820
       do_sys_openat2+0x160/0x1c0 fs/open.c:1407
       do_sys_open fs/open.c:1422 [inline]
       __do_sys_open fs/open.c:1430 [inline]
       __se_sys_open fs/open.c:1426 [inline]
       __x64_sys_open+0x11d/0x1c0 fs/open.c:1426
       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:3142 [inline]
       check_prevs_add kernel/locking/lockdep.c:3261 [inline]
       validate_chain kernel/locking/lockdep.c:3876 [inline]
       __lock_acquire+0x2e9d/0x5e20 kernel/locking/lockdep.c:5144
       lock_acquire kernel/locking/lockdep.c:5761 [inline]
       lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747
       process_measurement+0x678/0x1940 security/integrity/ima/ima_main.c:266
       ima_file_check+0xba/0x100 security/integrity/ima/ima_main.c:543
       do_open fs/namei.c:3638 [inline]
       path_openat+0x1588/0x2710 fs/namei.c:3793
       do_filp_open+0x1ba/0x410 fs/namei.c:3820
       do_sys_openat2+0x160/0x1c0 fs/open.c:1407
       do_sys_open fs/open.c:1422 [inline]
       __do_sys_openat fs/open.c:1438 [inline]
       __se_sys_openat fs/open.c:1433 [inline]
       __x64_sys_openat+0x143/0x1f0 fs/open.c:1433
       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
       ----                    ----
  rlock(sb_writers#4);
                               lock(&iint->mutex);
                               lock(sb_writers#4);
  lock(&iint->mutex);

 *** DEADLOCK ***

1 lock held by syz-executor.0/6616:
 #0: ffff88814c4b4410 (sb_writers#4){.+.+}-{0:0}, at: do_open fs/namei.c:3629 [inline]
 #0: ffff88814c4b4410 (sb_writers#4){.+.+}-{0:0}, at: path_openat+0x1959/0x2710 fs/namei.c:3793

stack backtrace:
CPU: 0 PID: 6616 Comm: syz-executor.0 Not tainted 6.4.0-next-20230707-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
 check_noncircular+0x2df/0x3b0 kernel/locking/lockdep.c:2195
 check_prev_add kernel/locking/lockdep.c:3142 [inline]
 check_prevs_add kernel/locking/lockdep.c:3261 [inline]
 validate_chain kernel/locking/lockdep.c:3876 [inline]
 __lock_acquire+0x2e9d/0x5e20 kernel/locking/lockdep.c:5144
 lock_acquire kernel/locking/lockdep.c:5761 [inline]
 lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5726
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747
 process_measurement+0x678/0x1940 security/integrity/ima/ima_main.c:266
 ima_file_check+0xba/0x100 security/integrity/ima/ima_main.c:543
 do_open fs/namei.c:3638 [inline]
 path_openat+0x1588/0x2710 fs/namei.c:3793
 do_filp_open+0x1ba/0x410 fs/namei.c:3820
 do_sys_openat2+0x160/0x1c0 fs/open.c:1407
 do_sys_open fs/open.c:1422 [inline]
 __do_sys_openat fs/open.c:1438 [inline]
 __se_sys_openat fs/open.c:1433 [inline]
 __x64_sys_openat+0x143/0x1f0 fs/open.c:1433
 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: 0033:0x7f44c508c389
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:00007f44c5eda168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f44c51abf80 RCX: 00007f44c508c389
RDX: 000000000000275a RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00007f44c50d7493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffed9fb304f R14: 00007f44c5eda300 R15: 0000000000022000
 </TASK>