======================================================
WARNING: possible circular locking dependency detected
6.6.0-syzkaller-03860-g5a6a09e97199 #0 Not tainted
------------------------------------------------------
syz-executor.4/31864 is trying to acquire lock:
ffff8880215a0418 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:404

but task is already holding lock:
ffff88802a08fbc0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7c9/0x1cf0 security/integrity/ima/ima_main.c:266

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&iint->mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
       process_measurement+0x7c9/0x1cf0 security/integrity/ima/ima_main.c:266
       ima_file_check+0xf1/0x170 security/integrity/ima/ima_main.c:543
       do_open fs/namei.c:3624 [inline]
       path_openat+0x2893/0x3280 fs/namei.c:3779
       do_filp_open+0x234/0x490 fs/namei.c:3809
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1440
       do_sys_open fs/open.c:1455 [inline]
       __do_sys_open fs/open.c:1463 [inline]
       __se_sys_open fs/open.c:1459 [inline]
       __x64_sys_open+0x225/0x270 fs/open.c:1459
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #0 (sb_writers#19){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3868 [inline]
       __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136
       lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1635 [inline]
       sb_start_write+0x4d/0x1c0 include/linux/fs.h:1710
       mnt_want_write+0x3f/0x90 fs/namespace.c:404
       ovl_maybe_copy_up+0x115/0x180 fs/overlayfs/copy_up.c:1176
       ovl_open+0x12b/0x310 fs/overlayfs/file.c:166
       do_dentry_open+0x8fd/0x1590 fs/open.c:948
       vfs_open fs/open.c:1082 [inline]
       dentry_open+0xcb/0x120 fs/open.c:1098
       ima_calc_file_hash+0x166/0x1d20 security/integrity/ima/ima_crypto.c:558
       ima_collect_measurement+0x4a5/0x890 security/integrity/ima/ima_api.c:289
       process_measurement+0xfea/0x1cf0 security/integrity/ima/ima_main.c:345
       ima_file_check+0xf1/0x170 security/integrity/ima/ima_main.c:543
       do_open fs/namei.c:3624 [inline]
       path_openat+0x2893/0x3280 fs/namei.c:3779
       do_filp_open+0x234/0x490 fs/namei.c:3809
       do_sys_openat2+0x13e/0x1d0 fs/open.c:1440
       do_sys_open fs/open.c:1455 [inline]
       __do_sys_open fs/open.c:1463 [inline]
       __se_sys_open fs/open.c:1459 [inline]
       __x64_sys_open+0x225/0x270 fs/open.c:1459
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&iint->mutex);
                               lock(sb_writers#19);
                               lock(&iint->mutex);
  rlock(sb_writers#19);

 *** DEADLOCK ***

1 lock held by syz-executor.4/31864:
 #0: ffff88802a08fbc0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x7c9/0x1cf0 security/integrity/ima/ima_main.c:266

stack backtrace:
CPU: 0 PID: 31864 Comm: syz-executor.4 Not tainted 6.6.0-syzkaller-03860-g5a6a09e97199 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x375/0x4a0 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:3868 [inline]
 __lock_acquire+0x39ff/0x7f70 kernel/locking/lockdep.c:5136
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1635 [inline]
 sb_start_write+0x4d/0x1c0 include/linux/fs.h:1710
 mnt_want_write+0x3f/0x90 fs/namespace.c:404
 ovl_maybe_copy_up+0x115/0x180 fs/overlayfs/copy_up.c:1176
 ovl_open+0x12b/0x310 fs/overlayfs/file.c:166
 do_dentry_open+0x8fd/0x1590 fs/open.c:948
 vfs_open fs/open.c:1082 [inline]
 dentry_open+0xcb/0x120 fs/open.c:1098
 ima_calc_file_hash+0x166/0x1d20 security/integrity/ima/ima_crypto.c:558
 ima_collect_measurement+0x4a5/0x890 security/integrity/ima/ima_api.c:289
 process_measurement+0xfea/0x1cf0 security/integrity/ima/ima_main.c:345
 ima_file_check+0xf1/0x170 security/integrity/ima/ima_main.c:543
 do_open fs/namei.c:3624 [inline]
 path_openat+0x2893/0x3280 fs/namei.c:3779
 do_filp_open+0x234/0x490 fs/namei.c:3809
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1440
 do_sys_open fs/open.c:1455 [inline]
 __do_sys_open fs/open.c:1463 [inline]
 __se_sys_open fs/open.c:1459 [inline]
 __x64_sys_open+0x225/0x270 fs/open.c:1459
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f526b47cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f526c2980c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f526b59bf80 RCX: 00007f526b47cae9
RDX: 0000000000000000 RSI: 0000000000088003 RDI: 0000000020000100
RBP: 00007f526b4c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f526b59bf80 R15: 00007ffdb6b33f38
 </TASK>