======================================================
WARNING: possible circular locking dependency detected
5.12.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.0/3431 is trying to acquire lock:
ffff888105e46460 (sb_writers#4){.+.+}-{0:0}, at: ovl_maybe_copy_up+0x77/0xa0 fs/overlayfs/copy_up.c:996

but task is already holding lock:
ffff888106c386d8 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x273/0x880 security/integrity/ima/ima_main.c:253

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:949 [inline]
       __mutex_lock+0x72/0x660 kernel/locking/mutex.c:1096
       process_measurement+0x273/0x880 security/integrity/ima/ima_main.c:253
       ima_file_check+0x5f/0x80 security/integrity/ima/ima_main.c:499
       do_open fs/namei.c:3367 [inline]
       path_openat+0x603/0xaf0 fs/namei.c:3498
       do_filp_open+0x83/0x130 fs/namei.c:3525
       do_sys_openat2+0x92/0x150 fs/open.c:1187
       do_sys_open fs/open.c:1203 [inline]
       __do_sys_openat fs/open.c:1219 [inline]
       __se_sys_openat fs/open.c:1214 [inline]
       __x64_sys_openat+0x4f/0x90 fs/open.c:1214
       do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #0 (sb_writers#4){.+.+}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:2936 [inline]
       check_prevs_add kernel/locking/lockdep.c:3059 [inline]
       validate_chain kernel/locking/lockdep.c:3674 [inline]
       __lock_acquire+0x110e/0x1b00 kernel/locking/lockdep.c:4900
       lock_acquire kernel/locking/lockdep.c:5510 [inline]
       lock_acquire+0xc7/0x380 kernel/locking/lockdep.c:5475
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1640 [inline]
       sb_start_write include/linux/fs.h:1710 [inline]
       mnt_want_write+0x32/0x1a0 fs/namespace.c:375
       ovl_maybe_copy_up+0x77/0xa0 fs/overlayfs/copy_up.c:996
       ovl_open+0x25/0x80 fs/overlayfs/file.c:149
       do_dentry_open+0x15c/0x3b0 fs/open.c:826
       vfs_open fs/open.c:940 [inline]
       dentry_open+0x5d/0xa0 fs/open.c:956
       ima_calc_file_hash+0xf9/0x160 security/integrity/ima/ima_crypto.c:557
       ima_collect_measurement+0x205/0x230 security/integrity/ima/ima_api.c:252
       process_measurement+0x3bd/0x880 security/integrity/ima/ima_main.c:330
       ima_file_check+0x5f/0x80 security/integrity/ima/ima_main.c:499
       do_open fs/namei.c:3367 [inline]
       path_openat+0x603/0xaf0 fs/namei.c:3498
       do_filp_open+0x83/0x130 fs/namei.c:3525
       do_sys_openat2+0x92/0x150 fs/open.c:1187
       do_sys_open fs/open.c:1203 [inline]
       __do_sys_open fs/open.c:1211 [inline]
       __se_sys_open fs/open.c:1207 [inline]
       __x64_sys_open+0x50/0x90 fs/open.c:1207
       do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xae

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.0/3431:
 #0: ffff888106c386d8 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x273/0x880 security/integrity/ima/ima_main.c:253

stack backtrace:
CPU: 0 PID: 3431 Comm: syz-executor.0 Not tainted 5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x7f/0xad lib/dump_stack.c:120
 check_noncircular+0xcc/0xe0 kernel/locking/lockdep.c:2127
 check_prev_add kernel/locking/lockdep.c:2936 [inline]
 check_prevs_add kernel/locking/lockdep.c:3059 [inline]
 validate_chain kernel/locking/lockdep.c:3674 [inline]
 __lock_acquire+0x110e/0x1b00 kernel/locking/lockdep.c:4900
 lock_acquire kernel/locking/lockdep.c:5510 [inline]
 lock_acquire+0xc7/0x380 kernel/locking/lockdep.c:5475
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1640 [inline]
 sb_start_write include/linux/fs.h:1710 [inline]
 mnt_want_write+0x32/0x1a0 fs/namespace.c:375
 ovl_maybe_copy_up+0x77/0xa0 fs/overlayfs/copy_up.c:996
 ovl_open+0x25/0x80 fs/overlayfs/file.c:149
 do_dentry_open+0x15c/0x3b0 fs/open.c:826
 vfs_open fs/open.c:940 [inline]
 dentry_open+0x5d/0xa0 fs/open.c:956
 ima_calc_file_hash+0xf9/0x160 security/integrity/ima/ima_crypto.c:557
 ima_collect_measurement+0x205/0x230 security/integrity/ima/ima_api.c:252
 process_measurement+0x3bd/0x880 security/integrity/ima/ima_main.c:330
 ima_file_check+0x5f/0x80 security/integrity/ima/ima_main.c:499
 do_open fs/namei.c:3367 [inline]
 path_openat+0x603/0xaf0 fs/namei.c:3498
 do_filp_open+0x83/0x130 fs/namei.c:3525
 do_sys_openat2+0x92/0x150 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_open fs/open.c:1211 [inline]
 __se_sys_open fs/open.c:1207 [inline]
 __x64_sys_open+0x50/0x90 fs/open.c:1207
 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa05ba91ae9
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:00007fa05b6140c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fa05bbb0f80 RCX: 00007fa05ba91ae9
RDX: 0000000000000000 RSI: 0000000000101003 RDI: 0000000020000000
RBP: 00007fa05badd47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000006 R14: 00007fa05bbb0f80 R15: 00007ffce33ecf48