======================================================
WARNING: possible circular locking dependency detected
6.1.60-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/2270 is trying to acquire lock:
ffff8881013a1460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0xe/0x30 fs/namespace.c:393

but task is already holding lock:
ffff888103b32c48 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x337/0x860 security/integrity/ima/ima_main.c:260

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+0x99/0x970 kernel/locking/mutex.c:747
       process_measurement+0x337/0x860 security/integrity/ima/ima_main.c:260
       ima_file_check+0x59/0x80 security/integrity/ima/ima_main.c:520
       do_open fs/namei.c:3560 [inline]
       path_openat+0xb2b/0xc70 fs/namei.c:3715
       do_filp_open+0xa8/0x150 fs/namei.c:3742
       do_sys_openat2+0x89/0x160 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __x64_sys_openat+0x78/0xa0 fs/open.c:1345
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0x80 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (sb_writers#4){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3824 [inline]
       __lock_acquire+0x1464/0x2830 kernel/locking/lockdep.c:5048
       lock_acquire+0xe3/0x270 kernel/locking/lockdep.c:5661
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1832 [inline]
       sb_start_write+0x34/0xd0 include/linux/fs.h:1907
       mnt_want_write+0xe/0x30 fs/namespace.c:393
       ovl_maybe_copy_up+0x74/0xa0 fs/overlayfs/copy_up.c:1090
       ovl_open+0x41/0xb0 fs/overlayfs/file.c:152
       do_dentry_open+0x24c/0x3c0 fs/open.c:882
       vfs_open fs/open.c:1013 [inline]
       dentry_open+0x54/0x90 fs/open.c:1029
       ima_calc_file_hash+0x5e/0xad0 security/integrity/ima/ima_crypto.c:558
       ima_collect_measurement+0x168/0x290 security/integrity/ima/ima_api.c:292
       process_measurement+0x513/0x860 security/integrity/ima/ima_main.c:337
       ima_file_check+0x59/0x80 security/integrity/ima/ima_main.c:520
       do_open fs/namei.c:3560 [inline]
       path_openat+0xb2b/0xc70 fs/namei.c:3715
       do_filp_open+0xa8/0x150 fs/namei.c:3742
       do_sys_openat2+0x89/0x160 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __x64_sys_openat+0x78/0xa0 fs/open.c:1345
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0x80 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(&iint->mutex);
                               lock(sb_writers#4);
                               lock(&iint->mutex);
  lock(sb_writers#4);

 *** DEADLOCK ***

1 lock held by syz-executor.0/2270:
 #0: ffff888103b32c48 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x337/0x860 security/integrity/ima/ima_main.c:260

stack backtrace:
CPU: 0 PID: 2270 Comm: syz-executor.0 Not tainted 6.1.60-syzkaller #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+0x89/0xd7 lib/dump_stack.c:106
 print_circular_bug+0x2c5/0x300 kernel/locking/lockdep.c:2048
 check_noncircular+0x106/0x110 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3824 [inline]
 __lock_acquire+0x1464/0x2830 kernel/locking/lockdep.c:5048
 lock_acquire+0xe3/0x270 kernel/locking/lockdep.c:5661
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1832 [inline]
 sb_start_write+0x34/0xd0 include/linux/fs.h:1907
 mnt_want_write+0xe/0x30 fs/namespace.c:393
 ovl_maybe_copy_up+0x74/0xa0 fs/overlayfs/copy_up.c:1090
 ovl_open+0x41/0xb0 fs/overlayfs/file.c:152
 do_dentry_open+0x24c/0x3c0 fs/open.c:882
 vfs_open fs/open.c:1013 [inline]
 dentry_open+0x54/0x90 fs/open.c:1029
 ima_calc_file_hash+0x5e/0xad0 security/integrity/ima/ima_crypto.c:558
 ima_collect_measurement+0x168/0x290 security/integrity/ima/ima_api.c:292
 process_measurement+0x513/0x860 security/integrity/ima/ima_main.c:337
 ima_file_check+0x59/0x80 security/integrity/ima/ima_main.c:520
 do_open fs/namei.c:3560 [inline]
 path_openat+0xb2b/0xc70 fs/namei.c:3715
 do_filp_open+0xa8/0x150 fs/namei.c:3742
 do_sys_openat2+0x89/0x160 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x78/0xa0 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f1159c7c959
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:00007f115a98a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1159d9bf80 RCX: 00007f1159c7c959
RDX: 0000000000000003 RSI: 0000000020000340 RDI: 0000000000000006
RBP: 00007f1159cd8c88 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000006 R14: 00007f1159d9bf80 R15: 00007ffc2fdfc718
 </TASK>