====================================================== WARNING: possible circular locking dependency detected 4.14.96+ #20 Not tainted ------------------------------------------------------ syz-executor0/16719 is trying to acquire lock: (&p->lock){+.+.}, at: [] seq_read+0xcd/0x1180 fs/seq_file.c:165 but task is already holding lock: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x58/0x70 fs/pipe.c:75 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&pipe->mutex/1){+.+.}: -> #1 (&sig->cred_guard_mutex){+.+.}: -> #0 (&p->lock){+.+.}: 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-executor0/16719: #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x58/0x70 fs/pipe.c:75 stack backtrace: CPU: 0 PID: 16719 Comm: syz-executor0 Not tainted 4.14.96+ #20 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 print_circular_bug.isra.0.cold+0x2dc/0x425 kernel/locking/lockdep.c:1258 IPv6: Can't replace route, no match found IPv6: Can't replace route, no match found kauditd_printk_skb: 414 callbacks suppressed audit: type=1400 audit(1548920879.904:511): avc: denied { relabelto } for pid=16919 comm="syz-executor2" name="file0" dev="sda1" ino=16785 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:null_device_t:s0 tclass=file permissive=1 audit: type=1400 audit(1548920879.954:512): avc: denied { read } for pid=16919 comm="syz-executor2" name="file0" dev="sda1" ino=16785 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:null_device_t:s0 tclass=file permissive=1 audit: type=1400 audit(1548920879.954:513): avc: denied { open } for pid=16919 comm="syz-executor2" path="/root/syzkaller-testdir138528622/syzkaller.kWondv/437/file0" dev="sda1" ino=16785 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:null_device_t:s0 tclass=file permissive=1 audit: type=1400 audit(1548920879.954:514): avc: denied { write } for pid=16919 comm="syz-executor2" name="file0" dev="sda1" ino=16785 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:null_device_t:s0 tclass=file permissive=1 audit: type=1400 audit(1548920879.974:515): avc: denied { relabelfrom } for pid=16919 comm="syz-executor2" name="file0" dev="sda1" ino=16785 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:null_device_t:s0 tclass=file permissive=1 audit: type=1400 audit(1548920879.984:516): avc: denied { getattr } for pid=3275 comm="syz-executor2" path="/root/syzkaller-testdir138528622/syzkaller.kWondv/437/file0" dev="sda1" ino=16785 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:null_device_t:s0 tclass=file permissive=1 audit: type=1400 audit(1548920879.984:517): avc: denied { unlink } for pid=3275 comm="syz-executor2" name="file0" dev="sda1" ino=16785 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:null_device_t:s0 tclass=file permissive=1 netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'. audit: type=1400 audit(1548920880.884:518): avc: denied { ioctl } for pid=17019 comm="syz-executor2" path="socket:[38065]" dev="sockfs" ino=38065 ioctlcmd=0x8946 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 audit: type=1400 audit(1548920880.894:519): avc: denied { getopt } for pid=17019 comm="syz-executor2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_netfilter_socket permissive=1 EXT4-fs warning (device sda1): verify_group_input:104: Cannot add at group 5 (only 16 groups) EXT4-fs warning (device sda1): verify_group_input:104: Cannot add at group 5 (only 16 groups) futex_wake_op: syz-executor4 tries to shift op by 4095; fix this program SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=17152 comm=syz-executor3 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=17155 comm=syz-executor3