random: crng init done
======================================================
[ INFO: possible circular locking dependency detected ]
4.9.128+ #45 Not tainted
-------------------------------------------------------
syz-executor957/2060 is trying to acquire lock:
(&p->lock){+.+.+.}, at: [<ffffffff8155eafd>] seq_read+0xdd/0x12d0 fs/seq_file.c:178
but task is already holding lock:
(&pipe->mutex/1){+.+.+.}, at: [<ffffffff815044be>] pipe_lock_nested fs/pipe.c:66 [inline]
(&pipe->mutex/1){+.+.+.}, at: [<ffffffff815044be>] pipe_lock+0x5e/0x70 fs/pipe.c:74
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
__mutex_lock_common kernel/locking/mutex.c:521 [inline]
mutex_lock_nested+0xc0/0x870 kernel/locking/mutex.c:621
__pipe_lock fs/pipe.c:87 [inline]
fifo_open+0x15c/0x9e0 fs/pipe.c:921
do_dentry_open+0x3ef/0xc90 fs/open.c:766
vfs_open+0x11c/0x210 fs/open.c:879
do_last fs/namei.c:3410 [inline]
path_openat+0x542/0x2790 fs/namei.c:3534
do_filp_open+0x197/0x270 fs/namei.c:3568
do_open_execat+0x10f/0x640 fs/exec.c:844
do_execveat_common.isra.15+0x687/0x1f80 fs/exec.c:1723
compat_do_execve fs/exec.c:1856 [inline]
C_SYSC_execve fs/exec.c:1931 [inline]
compat_SyS_execve+0x48/0x60 fs/exec.c:1927
do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
do_fast_syscall_32+0x2f1/0x860 arch/x86/entry/common.c:387
entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
__mutex_lock_common kernel/locking/mutex.c:521 [inline]
mutex_lock_killable_nested+0xcc/0x960 kernel/locking/mutex.c:641
lock_trace+0x44/0xc0 fs/proc/base.c:431
proc_pid_stack+0xdc/0x220 fs/proc/base.c:467
proc_single_show+0xfd/0x170 fs/proc/base.c:771
traverse+0x363/0x920 fs/seq_file.c:124
seq_read+0xd1b/0x12d0 fs/seq_file.c:195
do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718
do_loop_readv_writev fs/read_write.c:707 [inline]
do_readv_writev+0x56e/0x7b0 fs/read_write.c:873
vfs_readv+0x84/0xc0 fs/read_write.c:897
kernel_readv fs/splice.c:363 [inline]
default_file_splice_read+0x44b/0x7e0 fs/splice.c:435
do_splice_to+0x10c/0x170 fs/splice.c:899
splice_direct_to_actor+0x23f/0x7e0 fs/splice.c:971
do_splice_direct+0x1a3/0x270 fs/splice.c:1080
do_sendfile+0x4f0/0xc30 fs/read_write.c:1393
C_SYSC_sendfile fs/read_write.c:1469 [inline]
compat_SyS_sendfile+0xd1/0x160 fs/read_write.c:1458
do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
do_fast_syscall_32+0x2f1/0x860 arch/x86/entry/common.c:387
entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
check_prev_add kernel/locking/lockdep.c:1828 [inline]
check_prevs_add kernel/locking/lockdep.c:1938 [inline]
validate_chain kernel/locking/lockdep.c:2265 [inline]
__lock_acquire+0x3189/0x4a10 kernel/locking/lockdep.c:3345
lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
__mutex_lock_common kernel/locking/mutex.c:521 [inline]
mutex_lock_nested+0xc0/0x870 kernel/locking/mutex.c:621
seq_read+0xdd/0x12d0 fs/seq_file.c:178
proc_reg_read+0xfd/0x180 fs/proc/inode.c:203
do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718
do_loop_readv_writev fs/read_write.c:707 [inline]
do_readv_writev+0x56e/0x7b0 fs/read_write.c:873
vfs_readv+0x84/0xc0 fs/read_write.c:897
kernel_readv fs/splice.c:363 [inline]
default_file_splice_read+0x44b/0x7e0 fs/splice.c:435
do_splice_to+0x10c/0x170 fs/splice.c:899
do_splice fs/splice.c:1192 [inline]
SYSC_splice fs/splice.c:1416 [inline]
SyS_splice+0x10d2/0x14d0 fs/splice.c:1399
do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
do_fast_syscall_32+0x2f1/0x860 arch/x86/entry/common.c:387
entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
other info that might help us debug this:
Chain exists of:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&pipe->mutex/1);
lock(&sig->cred_guard_mutex);
lock(&pipe->mutex/1);
lock(&p->lock);
*** DEADLOCK ***
1 lock held by syz-executor957/2060:
#0: (&pipe->mutex/1){+.+.+.}, at: [<ffffffff815044be>] pipe_lock_nested fs/pipe.c:66 [inline]
#0: (&pipe->mutex/1){+.+.+.}, at: [<ffffffff815044be>] pipe_lock+0x5e/0x70 fs/pipe.c:74
stack backtrace:
CPU: 0 PID: 2060 Comm: syz-executor957 Not tainted 4.9.128+ #45
ffff8801ce017268 ffffffff81af2469 ffffffff83aa1330 ffffffff83aa7d80
ffffffff83aa2ad0 ffff8801d2445010 ffff8801d2444740 ffff8801ce0172b0
ffffffff813e79ed 0000000000000001 00000000d2444ff0 0000000000000001
Call Trace:
[<ffffffff81af2469>] __dump_stack lib/dump_stack.c:15 [inline]
[<ffffffff81af2469>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
[<ffffffff813e79ed>] print_circular_bug.cold.36+0x2f7/0x432 kernel/locking/lockdep.c:1202
[<ffffffff81202779>] check_prev_add kernel/locking/lockdep.c:1828 [inline]
[<ffffffff81202779>] check_prevs_add kernel/locking/lockdep.c:1938 [inline]
[<ffffffff81202779>] validate_chain kernel/locking/lockdep.c:2265 [inline]
[<ffffffff81202779>] __lock_acquire+0x3189/0x4a10 kernel/locking/lockdep.c:3345
[<ffffffff81204b10>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
[<ffffffff827826d0>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
[<ffffffff827826d0>] mutex_lock_nested+0xc0/0x870 kernel/locking/mutex.c:621
[<ffffffff8155eafd>] seq_read+0xdd/0x12d0 fs/seq_file.c:178
[<ffffffff8163438d>] proc_reg_read+0xfd/0x180 fs/proc/inode.c:203
[<ffffffff814ea805>] do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718
[<ffffffff814ebeae>] do_loop_readv_writev fs/read_write.c:707 [inline]
[<ffffffff814ebeae>] do_readv_writev+0x56e/0x7b0 fs/read_write.c:873
[<ffffffff814ec174>] vfs_readv+0x84/0xc0 fs/read_write.c:897
[<ffffffff81588a1b>] kernel_readv fs/splice.c:363 [inline]
[<ffffffff81588a1b>] default_file_splice_read+0x44b/0x7e0 fs/splice.c:435
[<ffffffff81587b1c>] do_splice_to+0x10c/0x170 fs/splice.c:899
[<ffffffff8158d062>] do_splice fs/splice.c:1192 [inline]
[<ffffffff8158d062>] SYSC_splice fs/splice.c:1416 [inline]
[<ffffffff8158d062>] SyS_splice+0x10d2/0x14d0 fs/splice.c:1399
[<ffffffff