======================================================
WARNING: possible circular locking dependency detected
4.19.211-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.5/2069 is trying to acquire lock:
00000000e7e26a90 (&sig->cred_guard_mutex){+.+.}, at: lock_trace fs/proc/base.c:402 [inline]
00000000e7e26a90 (&sig->cred_guard_mutex){+.+.}, at: proc_pid_syscall+0xb8/0x2f0 fs/proc/base.c:635
but task is already holding lock:
0000000076643451 (&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){.+.+}:
sb_start_write include/linux/fs.h:1579 [inline]
mnt_want_write+0x3a/0xb0 fs/namespace.c:360
ovl_create_object+0x96/0x290 fs/overlayfs/dir.c:602
lookup_open+0x893/0x1a20 fs/namei.c:3235
do_last fs/namei.c:3327 [inline]
path_openat+0x1094/0x2df0 fs/namei.c:3537
do_filp_open+0x18c/0x3f0 fs/namei.c:3567
do_sys_open+0x3b3/0x520 fs/open.c:1085
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #1 (&ovl_i_mutex_dir_key[depth]){++++}:
inode_lock_shared include/linux/fs.h:758 [inline]
do_last fs/namei.c:3326 [inline]
path_openat+0x17ec/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
lock_trace fs/proc/base.c:402 [inline]
proc_pid_syscall+0xb8/0x2f0 fs/proc/base.c:635
proc_single_show+0xeb/0x170 fs/proc/base.c:755
seq_read+0x4e0/0x11c0 fs/seq_file.c:232
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
do_preadv fs/read_write.c:1071 [inline]
__do_sys_preadv fs/read_write.c:1121 [inline]
__se_sys_preadv fs/read_write.c:1116 [inline]
__x64_sys_preadv+0x22b/0x310 fs/read_write.c:1116
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 ***
1 lock held by syz-executor.5/2069:
#0: 0000000076643451 (&p->lock){+.+.}, at: seq_read+0x6b/0x11c0 fs/seq_file.c:164
stack backtrace:
CPU: 0 PID: 2069 Comm: syz-executor.5 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
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
lock_trace fs/proc/base.c:402 [inline]
proc_pid_syscall+0xb8/0x2f0 fs/proc/base.c:635
proc_single_show+0xeb/0x170 fs/proc/base.c:755
seq_read+0x4e0/0x11c0 fs/seq_file.c:232
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
do_preadv fs/read_write.c:1071 [inline]
__do_sys_preadv fs/read_write.c:1121 [inline]
__se_sys_preadv fs/read_write.c:1116 [inline]
__x64_sys_preadv+0x22b/0x310 fs/read_write.c:1116
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f04f57ce279
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:00007f04f4143168 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 00007f04f58e0f80 RCX: 00007f04f57ce279
RDX: 00000000000001f4 RSI: 00000000200017c0 RDI: 0000000000000003
RBP: 00007f04f58282e9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeb3a0018f R14: 00007f04f4143300 R15: 0000000000022000
audit: type=1800 audit(1662311879.382:439): pid=2266 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="file0" dev="loop3" ino=19 res=0
attempt to access beyond end of device
loop3: rw=2049, want=128, limit=16
audit: type=1800 audit(1662311879.732:440): pid=2307 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="file0" dev="loop2" ino=20 res=0
attempt to access beyond end of device
loop2: rw=2049, want=128, limit=16
audit: type=1800 audit(1662311880.012:441): pid=2336 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="file0" dev="loop3" ino=21 res=0
attempt to access beyond end of device
loop3: rw=2049, want=128, limit=16
audit: type=1800 audit(1662311880.292:442): pid=2356 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="file0" dev="loop2" ino=22 res=0
attempt to access beyond end of device
loop2: rw=2049, want=128, limit=16
audit: type=1800 audit(1662311880.552:443): pid=2377 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="file0" dev="loop3" ino=23 res=0
audit: type=1800 audit(1662311880.752:444): pid=2393 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="file0" dev="loop2" ino=24 res=0
attempt to access beyond end of device
loop3: rw=2049, want=128, limit=16
attempt to access beyond end of device
loop2: rw=2049, want=128, limit=16
audit: type=1800 audit(1662311881.102:445): pid=2411 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="file0" dev="loop3" ino=25 res=0
audit: type=1800 audit(1662311881.282:446): pid=2433 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="file0" dev="loop3" ino=26 res=0
audit: type=1800 audit(1662311881.472:447): pid=2450 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="file0" dev="loop3" ino=27 res=0
audit: type=1800 audit(1662311881.672:448): pid=2486 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.3" name="file0" dev="loop3" ino=28 res=0
caif:caif_disconnect_client(): nothing to disconnect