syzbot

======================================================
WARNING: possible circular locking dependency detected
5.18.0-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.5/28242 is trying to acquire lock:
ffff88814bf9e460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:393

but task is already holding lock:
ffff88807e9401a0 (&iint->mutex){+.+.}-{3:3}, at: process_measurement+0x70c/0x1ca0 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}:
       lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5641
       __mutex_lock_common+0x1de/0x26e0 kernel/locking/mutex.c:600
       __mutex_lock kernel/locking/mutex.c:733 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:785
       process_measurement+0x70c/0x1ca0 security/integrity/ima/ima_main.c:260
       ima_file_check+0xe7/0x160 security/integrity/ima/ima_main.c:517
       do_open fs/namei.c:3478 [inline]
       path_openat+0x2705/0x2ec0 fs/namei.c:3609
       do_filp_open+0x277/0x4f0 fs/namei.c:3636
       do_sys_openat2+0x13b/0x500 fs/open.c:1213
       do_sys_open fs/open.c:1229 [inline]
       __do_sys_openat fs/open.c:1245 [inline]
       __se_sys_openat fs/open.c:1240 [inline]
       __x64_sys_openat+0x243/0x290 fs/open.c:1240
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x44/0xae

-> #0 (
sb_writers#4
){.+.+}-{0:0}
:
       check_prev_add kernel/locking/lockdep.c:3065 [inline]
       check_prevs_add kernel/locking/lockdep.c:3188 [inline]
       validate_chain+0x185c/0x65c0 kernel/locking/lockdep.c:3803
       __lock_acquire+0x129a/0x1f80 kernel/locking/lockdep.c:5029
       lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5641
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1698 [inline]
       sb_start_write+0x4d/0x1a0 include/linux/fs.h:1768
       mnt_want_write+0x3b/0x80 fs/namespace.c:393
       ovl_maybe_copy_up+0x124/0x190 fs/overlayfs/copy_up.c:1070
       ovl_open+0x9f/0x1f0 fs/overlayfs/file.c:150
       do_dentry_open+0x77f/0xfd0 fs/open.c:824
       vfs_open fs/open.c:958 [inline]
       dentry_open+0xc1/0x120 fs/open.c:974
       ima_calc_file_hash+0x157/0x1cb0 security/integrity/ima/ima_crypto.c:557
       ima_collect_measurement+0x292/0x530 security/integrity/ima/ima_api.c:252
       process_measurement+0xed8/0x1ca0 security/integrity/ima/ima_main.c:337
       ima_file_check+0xe7/0x160 security/integrity/ima/ima_main.c:517
       do_open fs/namei.c:3478 [inline]
       path_openat+0x2705/0x2ec0 fs/namei.c:3609
       do_filp_open+0x277/0x4f0 fs/namei.c:3636
       do_sys_openat2+0x13b/0x500 fs/open.c:1213
       do_sys_open fs/open.c:1229 [inline]
       __do_sys_open fs/open.c:1237 [inline]
       __se_sys_open fs/open.c:1233 [inline]
       __x64_sys_open+0x221/0x270 fs/open.c:1233
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
       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.5/28242:
 #0: ffff88807e9401a0
 (&iint->mutex
){+.+.}-{3:3}
, at: process_measurement+0x70c/0x1ca0 security/integrity/ima/ima_main.c:260

stack backtrace:
CPU: 0 PID: 28242 Comm: syz-executor.5 Not tainted 5.18.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2f7/0x3b0 kernel/locking/lockdep.c:2145
 check_prev_add kernel/locking/lockdep.c:3065 [inline]
 check_prevs_add kernel/locking/lockdep.c:3188 [inline]
 validate_chain+0x185c/0x65c0 kernel/locking/lockdep.c:3803
 __lock_acquire+0x129a/0x1f80 kernel/locking/lockdep.c:5029
 lock_acquire+0x1a7/0x400 kernel/locking/lockdep.c:5641
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 __sb_start_write include/linux/fs.h:1698 [inline]
 sb_start_write+0x4d/0x1a0 include/linux/fs.h:1768
 mnt_want_write+0x3b/0x80 fs/namespace.c:393
 ovl_maybe_copy_up+0x124/0x190 fs/overlayfs/copy_up.c:1070
 ovl_open+0x9f/0x1f0 fs/overlayfs/file.c:150
 do_dentry_open+0x77f/0xfd0 fs/open.c:824
 vfs_open fs/open.c:958 [inline]
 dentry_open+0xc1/0x120 fs/open.c:974
 ima_calc_file_hash+0x157/0x1cb0 security/integrity/ima/ima_crypto.c:557
 ima_collect_measurement+0x292/0x530 security/integrity/ima/ima_api.c:252
 process_measurement+0xed8/0x1ca0 security/integrity/ima/ima_main.c:337
 ima_file_check+0xe7/0x160 security/integrity/ima/ima_main.c:517
 do_open fs/namei.c:3478 [inline]
 path_openat+0x2705/0x2ec0 fs/namei.c:3609
 do_filp_open+0x277/0x4f0 fs/namei.c:3636
 do_sys_openat2+0x13b/0x500 fs/open.c:1213
 do_sys_open fs/open.c:1229 [inline]
 __do_sys_open fs/open.c:1237 [inline]
 __se_sys_open fs/open.c:1233 [inline]
 __x64_sys_open+0x221/0x270 fs/open.c:1233
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f9c13a890e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9c14bb3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f9c13b9bf60 RCX: 00007f9c13a890e9
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000020000040
RBP: 00007f9c13ae308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff717c162f R14: 00007f9c14bb3300 R15: 0000000000022000
 </TASK>