[ INFO: possible circular locking dependency detected ]
4.9.141+ #23 Not tainted
-------------------------------------------------------
syz-executor.0/8979 is trying to acquire lock:
(&p->lock){+.+.+.}, at: [<ffffffff8158080d>] seq_read+0xdd/0x12d0 fs/seq_file.c:178
but task is already holding lock:
(&pipe->mutex/1){+.+.+.}, at: [<ffffffff81523c1e>] pipe_lock_nested fs/pipe.c:66 [inline]
(&pipe->mutex/1){+.+.+.}, at: [<ffffffff81523c1e>] pipe_lock+0x5e/0x70 fs/pipe.c:74
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&pipe->mutex/1){+.+.+.}:
lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
__mutex_lock_common kernel/locking/mutex.c:521 [inline]
mutex_lock_nested+0xc0/0x900 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.14+0x687/0x1ed0 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:328 [inline]
do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
-> #1 (&sig->cred_guard_mutex){+.+.+.}:
lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
__mutex_lock_common kernel/locking/mutex.c:521 [inline]
mutex_lock_killable_nested+0xcc/0x9f0 kernel/locking/mutex.c:641
lock_trace+0x44/0xc0 fs/proc/base.c:431
proc_pid_syscall+0xa9/0x260 fs/proc/base.c:663
proc_single_show+0xfd/0x170 fs/proc/base.c:785
seq_read+0x4b6/0x12d0 fs/seq_file.c:240
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+0x451/0x7f0 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:1475 [inline]
compat_SyS_sendfile+0x143/0x160 fs/read_write.c:1458
do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline]
do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
-> #0 (&p->lock){+.+.+.}:
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+0xc0/0x900 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+0x451/0x7f0 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:328 [inline]
do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
other info that might help us debug this:
Chain exists of:
&p->lock --> &sig->cred_guard_mutex --> &pipe->mutex/1
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-executor.0/8979:
#0: (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81523c1e>] pipe_lock_nested fs/pipe.c:66 [inline]
#0: (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81523c1e>] pipe_lock+0x5e/0x70 fs/pipe.c:74
stack backtrace:
CPU: 1 PID: 8979 Comm: syz-executor.0 Not tainted 4.9.141+ #23
ffff8801a30af268 ffffffff81b42e79 ffffffff83ca2fd0 ffffffff83caa290
ffffffff83ca4fe0 ffff8801c538b850 ffff8801c538af80 ffff8801a30af2b0
ffffffff813fee40 0000000000000001 00000000c538b830 0000000000000001
Call Trace:
[<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
[<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
[<ffffffff813fee40>] print_circular_bug.cold.36+0x2f7/0x432 kernel/locking/lockdep.c:1202
[<ffffffff8120a539>] check_prev_add kernel/locking/lockdep.c:1828 [inline]
[<ffffffff8120a539>] check_prevs_add kernel/locking/lockdep.c:1938 [inline]
[<ffffffff8120a539>] validate_chain kernel/locking/lockdep.c:2265 [inline]
[<ffffffff8120a539>] __lock_acquire+0x3189/0x4a10 kernel/locking/lockdep.c:3345
[<ffffffff8120c8d0>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
[<ffffffff8280b250>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
[<ffffffff8280b250>] mutex_lock_nested+0xc0/0x900 kernel/locking/mutex.c:621
[<ffffffff8158080d>] seq_read+0xdd/0x12d0 fs/seq_file.c:178
[<ffffffff8165c00d>] proc_reg_read+0xfd/0x180 fs/proc/inode.c:203
[<ffffffff81509df5>] do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718
[<ffffffff8150b49e>] do_loop_readv_writev fs/read_write.c:707 [inline]
[<ffffffff8150b49e>] do_readv_writev+0x56e/0x7b0 fs/read_write.c:873
[<ffffffff8150b764>] vfs_readv+0x84/0xc0 fs/read_write.c:897
[<ffffffff815ac2a1>] kernel_readv fs/splice.c:363 [inline]
[<ffffffff815ac2a1>] default_file_splice_read+0x451/0x7f0 fs/splice.c:435
[<ffffffff815ab39c>] do_splice_to+0x10c/0x170 fs/splice.c:899
[<ffffffff815b08f2>] do_splice fs/splice.c:1192 [inline]
[<ffffffff815b08f2>] SYSC_splice fs/splice.c:1416 [inline]
[<ffffffff815b08f2>] SyS_splice+0x10d2/0x14d0 fs/splice.c:1399
[<ffffffff81006311>] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline]
[<ffffffff81006311>] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
[<ffffffff82818de0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137
audit: type=1400 audit(1575356668.040:177440): avc: denied { net_admin } for pid=8971 comm="syz-executor.4" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356668.040:177441): avc: denied { dac_override } for pid=8973 comm="syz-executor.3" capability=1 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356668.060:177442): avc: denied { dac_override } for pid=8976 comm="syz-executor.0" capability=1 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356668.080:177443): avc: denied { sys_admin } for pid=2077 comm="syz-executor.0" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit_printk_skb: 1944 callbacks suppressed
audit: type=1400 audit(1575356672.850:178093): avc: denied { net_admin } for pid=2081 comm="syz-executor.4" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.850:178094): avc: denied { sys_admin } for pid=2079 comm="syz-executor.5" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.850:178095): avc: denied { sys_admin } for pid=2079 comm="syz-executor.5" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.860:178096): avc: denied { sys_admin } for pid=2079 comm="syz-executor.5" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.840:178092): avc: denied { net_admin } for pid=2080 comm="syz-executor.3" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.860:178097): avc: denied { sys_admin } for pid=2079 comm="syz-executor.5" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.860:178098): avc: denied { net_admin } for pid=2080 comm="syz-executor.3" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.880:178099): avc: denied { net_admin } for pid=2080 comm="syz-executor.3" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.880:178100): avc: denied { net_admin } for pid=2080 comm="syz-executor.3" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356672.880:178101): avc: denied { net_admin } for pid=2080 comm="syz-executor.3" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit_printk_skb: 3132 callbacks suppressed
audit: type=1400 audit(1575356677.860:179146): avc: denied { net_admin } for pid=2081 comm="syz-executor.4" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.870:179147): avc: denied { sys_admin } for pid=2077 comm="syz-executor.0" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.880:179148): avc: denied { sys_admin } for pid=2077 comm="syz-executor.0" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.880:179150): avc: denied { sys_admin } for pid=2077 comm="syz-executor.0" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.880:179151): avc: denied { sys_admin } for pid=2077 comm="syz-executor.0" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.880:179149): avc: denied { sys_admin } for pid=15236 comm="syz-executor.2" capability=21 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.910:179152): avc: denied { net_admin } for pid=2077 comm="syz-executor.0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.930:179153): avc: denied { net_admin } for pid=2077 comm="syz-executor.0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.930:179154): avc: denied { net_admin } for pid=2077 comm="syz-executor.0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1
audit: type=1400 audit(1575356677.930:179155): avc: denied { net_admin } for pid=2077 comm="syz-executor.0" capability=12 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=cap_userns permissive=1