======================================================
WARNING: possible circular locking dependency detected
4.19.211-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.2/14008 is trying to acquire lock:
00000000bb5f4367 (&sig->cred_guard_mutex){+.+.}, at: do_io_accounting fs/proc/base.c:2750 [inline]
00000000bb5f4367 (&sig->cred_guard_mutex){+.+.}, at: proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799

but task is already holding lock:
00000000c6268101 (&p->lock){+.+.}, at: seq_read+0x6b/0x11c0 fs/seq_file.c:164

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&p->lock){+.+.}:
       seq_read+0x6b/0x11c0 fs/seq_file.c:164
       proc_reg_read+0x1bd/0x2d0 fs/proc/inode.c:231
       do_loop_readv_writev fs/read_write.c:701 [inline]
       do_loop_readv_writev fs/read_write.c:688 [inline]
       do_iter_read+0x471/0x630 fs/read_write.c:925
       vfs_readv+0xe5/0x150 fs/read_write.c:987
       kernel_readv fs/splice.c:362 [inline]
       default_file_splice_read+0x457/0xa00 fs/splice.c:417
       do_splice_to+0x10e/0x160 fs/splice.c:881
       splice_direct_to_actor+0x2b9/0x8d0 fs/splice.c:959
       do_splice_direct+0x1a7/0x270 fs/splice.c:1068
       do_sendfile+0x550/0xc30 fs/read_write.c:1447
       __do_sys_sendfile64 fs/read_write.c:1508 [inline]
       __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494
       do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #2 (sb_writers#3){.+.+}:
       file_start_write include/linux/fs.h:2779 [inline]
       ovl_write_iter+0x932/0xb40 fs/overlayfs/file.c:282
       call_write_iter include/linux/fs.h:1821 [inline]
       new_sync_write fs/read_write.c:474 [inline]
       __vfs_write+0x51b/0x770 fs/read_write.c:487
       vfs_write+0x1f3/0x540 fs/read_write.c:549
       ksys_write+0x12b/0x2a0 fs/read_write.c:599
       do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #1 (&ovl_i_mutex_key[depth]){+.+.}:
       inode_lock include/linux/fs.h:748 [inline]
       process_measurement+0x926/0x1440 security/integrity/ima/ima_main.c:205
       ima_file_check+0xb9/0x100 security/integrity/ima/ima_main.c:391
       do_last fs/namei.c:3425 [inline]
       path_openat+0x7e4/0x2df0 fs/namei.c:3537
       do_filp_open+0x18c/0x3f0 fs/namei.c:3567
       do_open_execat+0x11d/0x5b0 fs/exec.c:853
       __do_execve_file+0x1a8b/0x2360 fs/exec.c:1770
       do_execveat_common fs/exec.c:1879 [inline]
       do_execve+0x35/0x50 fs/exec.c:1896
       __do_sys_execve fs/exec.c:1977 [inline]
       __se_sys_execve fs/exec.c:1972 [inline]
       __x64_sys_execve+0x7c/0xa0 fs/exec.c:1972
       do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (&sig->cred_guard_mutex){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:937 [inline]
       __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078
       do_io_accounting fs/proc/base.c:2750 [inline]
       proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799
       proc_single_show+0xeb/0x170 fs/proc/base.c:755
       seq_read+0x4e0/0x11c0 fs/seq_file.c:232
       __vfs_read+0xf7/0x750 fs/read_write.c:416
       vfs_read+0x194/0x3c0 fs/read_write.c:452
       ksys_read+0x12b/0x2a0 fs/read_write.c:579
       do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
  &sig->cred_guard_mutex --> sb_writers#3 --> &p->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&p->lock);
                               lock(sb_writers#3);
                               lock(&p->lock);
  lock(&sig->cred_guard_mutex);

 *** DEADLOCK ***

2 locks held by syz-executor.2/14008:
 #0: 0000000042beb6a6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
 #1: 00000000c6268101 (&p->lock){+.+.}, at: seq_read+0x6b/0x11c0 fs/seq_file.c:164

stack backtrace:
CPU: 0 PID: 14008 Comm: syz-executor.2 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222
 check_prev_add kernel/locking/lockdep.c:1866 [inline]
 check_prevs_add kernel/locking/lockdep.c:1979 [inline]
 validate_chain kernel/locking/lockdep.c:2420 [inline]
 __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
 __mutex_lock_common kernel/locking/mutex.c:937 [inline]
 __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078
 do_io_accounting fs/proc/base.c:2750 [inline]
 proc_tgid_io_accounting+0x1cf/0x7f0 fs/proc/base.c:2799
 proc_single_show+0xeb/0x170 fs/proc/base.c:755
 seq_read+0x4e0/0x11c0 fs/seq_file.c:232
 __vfs_read+0xf7/0x750 fs/read_write.c:416
 vfs_read+0x194/0x3c0 fs/read_write.c:452
 ksys_read+0x12b/0x2a0 fs/read_write.c:579
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fa5ff9095a9
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:00007fa5fe27d168 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fa5ffa2af80 RCX: 00007fa5ff9095a9
RDX: 0000000000002020 RSI: 0000000020009e00 RDI: 0000000000000003
RBP: 00007fa5ff964580 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdacb2ec4f R14: 00007fa5fe27d300 R15: 0000000000022000
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
netlink: 12 bytes leftover after parsing attributes in process `syz-executor.3'.
isofs_fill_super: root inode is not a directory. Corrupted media?
netlink: 68 bytes leftover after parsing attributes in process `syz-executor.3'.
netlink: 'syz-executor.3': attribute type 1 has an invalid length.
netlink: 'syz-executor.3': attribute type 2 has an invalid length.
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
xt_CT: netfilter: NOTRACK target is deprecated, use CT instead or upgrade iptables
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready
chnl_net:chnl_net_open(): err: Unable to register and open device, Err:-19
caif:caif_disconnect_client(): nothing to disconnect
chnl_net:chnl_flowctrl_cb(): NET flowctrl func called flow: CLOSE/DEINIT
chnl_net:chnl_net_open(): state disconnected
ISOFS: File unit size != 0 for ISO file (1792).
A link change request failed with some changes committed already. Interface caif0 may have been left with an inconsistent configuration, please check.
isofs_fill_super: root inode is not a directory. Corrupted media?
netlink: 4 bytes leftover after parsing attributes in process `syz-executor.3'.
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?
ISOFS: File unit size != 0 for ISO file (1792).
isofs_fill_super: root inode is not a directory. Corrupted media?