======================================================
WARNING: possible circular locking dependency detected
6.4.0-rc2-next-20230515-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor381/5122 is trying to acquire lock:
ffff888073aef740 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x67b/0x1930 security/integrity/ima/ima_main.c:262

but task is already holding lock:
ffff88814c4c0460 (sb_writers#4){.+.+}-{0:0}, at: do_open fs/namei.c:3629 [inline]
ffff88814c4c0460 (sb_writers#4){.+.+}-{0:0}, at: path_openat+0x19a4/0x2750 fs/namei.c:3791

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:394
       ovl_maybe_copy_up+0x123/0x190 fs/overlayfs/copy_up.c:1124
       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:3638 [inline]
       path_openat+0x15d3/0x2750 fs/namei.c:3791
       do_filp_open+0x1ba/0x410 fs/namei.c:3818
       do_sys_openat2+0x16d/0x4c0 fs/open.c:1356
       do_sys_open fs/open.c:1372 [inline]
       __do_sys_open fs/open.c:1380 [inline]
       __se_sys_open fs/open.c:1376 [inline]
       __x64_sys_open+0x11d/0x1c0 fs/open.c:1376
       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:3113 [inline]
       check_prevs_add kernel/locking/lockdep.c:3232 [inline]
       validate_chain kernel/locking/lockdep.c:3847 [inline]
       __lock_acquire+0x2fcd/0x5f30 kernel/locking/lockdep.c:5088
       lock_acquire.part.0+0x11c/0x370 kernel/locking/lockdep.c:5705
       __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:3638 [inline]
       path_openat+0x15d3/0x2750 fs/namei.c:3791
       do_filp_open+0x1ba/0x410 fs/namei.c:3818
       do_sys_openat2+0x16d/0x4c0 fs/open.c:1356
       do_sys_open fs/open.c:1372 [inline]
       __do_sys_open fs/open.c:1380 [inline]
       __se_sys_open fs/open.c:1376 [inline]
       __x64_sys_open+0x11d/0x1c0 fs/open.c:1376
       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-executor381/5122:
 #0: ffff88814c4c0460 (sb_writers#4){.+.+}-{0:0}, at: do_open fs/namei.c:3629 [inline]
 #0: ffff88814c4c0460 (sb_writers#4){.+.+}-{0:0}, at: path_openat+0x19a4/0x2750 fs/namei.c:3791

stack backtrace:
CPU: 1 PID: 5122 Comm: syz-executor381 Not tainted 6.4.0-rc2-next-20230515-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
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:2188
 check_prev_add kernel/locking/lockdep.c:3113 [inline]
 check_prevs_add kernel/locking/lockdep.c:3232 [inline]
 validate_chain kernel/locking/lockdep.c:3847 [inline]
 __lock_acquire+0x2fcd/0x5f30 kernel/locking/lockdep.c:5088
 lock_acquire.part.0+0x11c/0x370 kernel/locking/lockdep.c:5705
 __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:3638 [inline]
 path_openat+0x15d3/0x2750 fs/namei.c:3791
 do_filp_open+0x1ba/0x410 fs/namei.c:3818
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1356
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_open fs/open.c:1380 [inline]
 __se_sys_open fs/open.c:1376 [inline]
 __x64_sys_open+0x11d/0x1c0 fs/open.c:1376
 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: 0033:0x7f7e97fd7b59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe72981dd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0031656c69662f2e RCX: 00007f7e97fd7b59
RDX: 0000000000000000 RSI: 000000000014d27e RDI: 0000000020000180
RBP: 0000000000000000 R08: 00007ffe72981e00 R09: 00007ffe72981e00
R10: 00007ffe72981e00 R11: 0000000000000246 R12: 00007ffe72981dfc
R13: 00007ffe72981e30 R14: 00007ffe72981e10 R15: 0000000000000008
 </TASK>