======================================================
WARNING: possible circular locking dependency detected
4.14.76+ #19 Not tainted
------------------------------------------------------
syz-executor4/10642 is trying to acquire lock:
(&sig->cred_guard_mutex){+.+.}, at: [<ffffffffa3e9e8f7>] do_io_accounting+0x1d7/0x770 fs/proc/base.c:2731
but task is already holding lock:
(&p->lock){+.+.}, at: [<ffffffffa3dd0bb4>] seq_read+0xd4/0x11d0 fs/seq_file.c:165
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&p->lock){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xf5/0x1480 kernel/locking/mutex.c:893
seq_read+0xd4/0x11d0 fs/seq_file.c:165
proc_reg_read+0xef/0x170 fs/proc/inode.c:217
do_loop_readv_writev fs/read_write.c:698 [inline]
do_iter_read+0x3cc/0x580 fs/read_write.c:922
vfs_readv+0xe6/0x150 fs/read_write.c:984
kernel_readv fs/splice.c:361 [inline]
default_file_splice_read+0x495/0x860 fs/splice.c:416
do_splice_to+0x102/0x150 fs/splice.c:880
do_splice fs/splice.c:1173 [inline]
SYSC_splice fs/splice.c:1402 [inline]
SyS_splice+0xf4d/0x12a0 fs/splice.c:1382
do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
entry_SYSCALL_64_after_hwframe+0x42/0xb7
-> #1 (&pipe->mutex/1){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xf5/0x1480 kernel/locking/mutex.c:893
__pipe_lock fs/pipe.c:88 [inline]
fifo_open+0x156/0x9d0 fs/pipe.c:921
do_dentry_open+0x426/0xda0 fs/open.c:764
vfs_open+0x11c/0x210 fs/open.c:878
do_last fs/namei.c:3408 [inline]
path_openat+0x4eb/0x23a0 fs/namei.c:3550
do_filp_open+0x197/0x270 fs/namei.c:3584
do_open_execat+0x10d/0x5b0 fs/exec.c:849
do_execveat_common.isra.14+0x6cb/0x1d60 fs/exec.c:1740
do_execve fs/exec.c:1847 [inline]
SYSC_execve fs/exec.c:1928 [inline]
SyS_execve+0x34/0x40 fs/exec.c:1923
do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
entry_SYSCALL_64_after_hwframe+0x42/0xb7
-> #0 (&sig->cred_guard_mutex){+.+.}:
lock_acquire+0x10f/0x380 kernel/locking/lockdep.c:3991
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xf5/0x1480 kernel/locking/mutex.c:893
do_io_accounting+0x1d7/0x770 fs/proc/base.c:2731
proc_single_show+0xf1/0x160 fs/proc/base.c:762
seq_read+0x4e0/0x11d0 fs/seq_file.c:237
do_loop_readv_writev fs/read_write.c:698 [inline]
do_iter_read+0x3cc/0x580 fs/read_write.c:922
vfs_readv+0xe6/0x150 fs/read_write.c:984
do_preadv+0x187/0x230 fs/read_write.c:1068
do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
entry_SYSCALL_64_after_hwframe+0x42/0xb7
other info that might help us debug this:
Chain exists of:
&sig->cred_guard_mutex --> &pipe->mutex/1 --> &p->lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&p->lock);
lock(&pipe->mutex/1);
lock(&p->lock);
lock(&sig->cred_guard_mutex);
*** DEADLOCK ***
1 lock held by syz-executor4/10642:
#0: (&p->lock){+.+.}, at: [<ffffffffa3dd0bb4>] seq_read+0xd4/0x11d0 fs/seq_file.c:165
stack backtrace:
CPU: 1 PID: 10642 Comm: syz-executor4 Not tainted 4.14.76+ #19
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0xb9/0x11b lib/dump_stack.c:53
print_circular_bug.isra.18.cold.43+0x2d3/0x40c kernel/locking/lockdep.c:1258
check_prev_add kernel/locking/lockdep.c:1901 [inline]
check_prevs_add kernel/locking/lockdep.c:2018 [inline]
validate_chain kernel/locking/lockdep.c:2460 [inline]
__lock_acquire+0x2ff9/0x4320 kernel/locking/lockdep.c:3487
lock_acquire+0x10f/0x380 kernel/locking/lockdep.c:3991
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xf5/0x1480 kernel/locking/mutex.c:893
do_io_accounting+0x1d7/0x770 fs/proc/base.c:2731
proc_single_show+0xf1/0x160 fs/proc/base.c:762
seq_read+0x4e0/0x11d0 fs/seq_file.c:237
do_loop_readv_writev fs/read_write.c:698 [inline]
do_iter_read+0x3cc/0x580 fs/read_write.c:922
vfs_readv+0xe6/0x150 fs/read_write.c:984
do_preadv+0x187/0x230 fs/read_write.c:1068
do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457569
RSP: 002b:00007f4abff06c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457569
RDX: 10000000000001e1 RSI: 0000000020000480 RDI: 0000000000000004
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4abff076d4
R13: 00000000004c3088 R14: 00000000004d4a40 R15: 00000000ffffffff
EXT4-fs (loop5): VFS: Can't find ext4 filesystem
kauditd_printk_skb: 318 callbacks suppressed
audit: type=1400 audit(2000000159.630:14812): avc: denied { map } for pid=10684 comm="modprobe" path="/lib/x86_64-linux-gnu/libkmod.so.2.1.3" dev="sda1" ino=2811 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: type=1400 audit(2000000159.640:14813): avc: denied { map } for pid=10690 comm="blkid" path="/lib/x86_64-linux-gnu/ld-2.13.so" dev="sda1" ino=2668 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: type=1400 audit(2000000159.660:14814): avc: denied { map } for pid=10687 comm="blkid" path="/etc/ld.so.cache" dev="sda1" ino=2503 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1
audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_lost=867 audit_rate_limit=0 audit_backlog_limit=64
audit: backlog limit exceeded
audit: audit_backlog=65 > audit_backlog_limit=64
audit: audit_lost=868 audit_rate_limit=0 audit_backlog_limit=64
audit: backlog limit exceeded
audit: audit_backlog=65 > audit_backlog_limit=64
EXT4-fs (sda1): Unrecognized mount option "inod�̽�%��N��e_readaheadϭ��qw�?i;9_blks=0x0000000��Ǯ�p�.�EY�(Ƌ(f~
�ô� �HU�@�U�j" or missing value
EXT4-fs (sda1): Unrecognized mount option "inod�̽�%��N��e_readaheadϭ��qw�?i;9_blks=0x0000000��Ǯ�p�.�EY�(Ƌ(f~
�ô� �HU�@�U�j" or missing value