======================================================
WARNING: possible circular locking dependency detected
5.7.0-rc6-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.3/18556 is trying to acquire lock:
ffff8880a8a0ace0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x362/0x1750 security/integrity/ima/ima_main.c:247

but task is already holding lock:
ffff888214a62450 (sb_writers#3){.+.+}-{0:0}, at: sb_start_write include/linux/fs.h:1655 [inline]
ffff888214a62450 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:354

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sb_writers#3){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write+0x230/0x470 fs/super.c:1674
       sb_start_write include/linux/fs.h:1655 [inline]
       mnt_want_write+0x3a/0xb0 fs/namespace.c:354
       ovl_maybe_copy_up+0x120/0x190 fs/overlayfs/copy_up.c:960
       ovl_open+0xba/0x270 fs/overlayfs/file.c:132
       do_dentry_open+0x4ba/0x1290 fs/open.c:797
       vfs_open fs/open.c:911 [inline]
       dentry_open+0x132/0x1d0 fs/open.c:927
       ima_calc_file_hash+0x333/0x560 security/integrity/ima/ima_crypto.c:431
       ima_collect_measurement+0x4ca/0x570 security/integrity/ima/ima_api.c:249
       process_measurement+0xc79/0x1750 security/integrity/ima/ima_main.c:324
       ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:440
       do_open fs/namei.c:3231 [inline]
       path_openat+0x1997/0x27d0 fs/namei.c:3346
       do_filp_open+0x192/0x260 fs/namei.c:3373
       do_sys_openat2+0x585/0x7d0 fs/open.c:1148
       do_sys_open+0xc3/0x140 fs/open.c:1164
       do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
       entry_SYSCALL_64_after_hwframe+0x49/0xb3

-> #0 (&iint->mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:2515 [inline]
       check_prevs_add kernel/locking/lockdep.c:2620 [inline]
       validate_chain kernel/locking/lockdep.c:3237 [inline]
       __lock_acquire+0x2ab1/0x4c50 kernel/locking/lockdep.c:4355
       lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934
       __mutex_lock_common kernel/locking/mutex.c:956 [inline]
       __mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
       process_measurement+0x362/0x1750 security/integrity/ima/ima_main.c:247
       ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:440
       do_open fs/namei.c:3231 [inline]
       path_openat+0x1997/0x27d0 fs/namei.c:3346
       do_filp_open+0x192/0x260 fs/namei.c:3373
       do_sys_openat2+0x585/0x7d0 fs/open.c:1148
       do_sys_open+0xc3/0x140 fs/open.c:1164
       do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
       entry_SYSCALL_64_after_hwframe+0x49/0xb3

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_writers#3);
                               lock(&iint->mutex);
                               lock(sb_writers#3);
  lock(&iint->mutex);

 *** DEADLOCK ***

1 lock held by syz-executor.3/18556:
 #0: ffff888214a62450 (sb_writers#3){.+.+}-{0:0}, at: sb_start_write include/linux/fs.h:1655 [inline]
 #0: ffff888214a62450 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:354

stack backtrace:
CPU: 1 PID: 18556 Comm: syz-executor.3 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 check_noncircular+0x32e/0x3e0 kernel/locking/lockdep.c:1846
 check_prev_add kernel/locking/lockdep.c:2515 [inline]
 check_prevs_add kernel/locking/lockdep.c:2620 [inline]
 validate_chain kernel/locking/lockdep.c:3237 [inline]
 __lock_acquire+0x2ab1/0x4c50 kernel/locking/lockdep.c:4355
 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934
 __mutex_lock_common kernel/locking/mutex.c:956 [inline]
 __mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1103
 process_measurement+0x362/0x1750 security/integrity/ima/ima_main.c:247
 ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:440
 do_open fs/namei.c:3231 [inline]
 path_openat+0x1997/0x27d0 fs/namei.c:3346
 do_filp_open+0x192/0x260 fs/namei.c:3373
 do_sys_openat2+0x585/0x7d0 fs/open.c:1148
 do_sys_open+0xc3/0x140 fs/open.c:1164
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca29
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f6d2c2ebc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00000000004f6c80 RCX: 000000000045ca29
RDX: 0000000000000000 RSI: 000000000000ff00 RDI: 0000000020000300
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000779 R14: 000000000052565f R15: 00007f6d2c2ec6d4
overlayfs: upperdir is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection.