====================================================== [ INFO: possible circular locking dependency detected ] 4.9.141+ #23 Not tainted ------------------------------------------------------- syz-executor.0/7578 is trying to acquire lock: (&p->lock){+.+.+.}, at: [] seq_read+0xdd/0x12d0 fs/seq_file.c:178 but task is already holding lock: (&pipe->mutex/1){+.+.+.}, at: [] pipe_lock_nested fs/pipe.c:66 [inline] (&pipe->mutex/1){+.+.+.}, at: [] 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+0xc0/0x900 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 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 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: 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.0/7578: #0: (&pipe->mutex/1){+.+.+.}, at: [] pipe_lock_nested fs/pipe.c:66 [inline] #0: (&pipe->mutex/1){+.+.+.}, at: [] pipe_lock+0x5e/0x70 fs/pipe.c:74 stack backtrace: CPU: 0 PID: 7578 Comm: syz-executor.0 Not tainted 4.9.141+ #23 ffff880198907268 ffffffff81b42e79 ffffffff83ca2fd0 ffffffff83ca9f30 ffffffff83ca4fe0 ffff8801d42788d0 ffff8801d4278000 ffff8801989072b0 ffffffff813fee40 0000000000000001 00000000d42788b0 0000000000000001 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_circular_bug.cold.36+0x2f7/0x432 kernel/locking/lockdep.c:1202 [] 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 binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: BINDER_SET_CONTEXT_MGR already set binder: 7602:7606 ioctl 40046207 0 returned -16 binder: undelivered transaction 9, process died. binder: undelivered transaction 8, process died. audit_printk_skb: 1704 callbacks suppressed audit: type=1400 audit(1575128934.176:1924): avc: denied { dac_override } for pid=7604 comm="syz-executor.5" 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(1575128934.186:1925): avc: denied { sys_admin } for pid=2073 comm="syz-executor.4" 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(1575128934.186:1926): avc: denied { net_admin } for pid=2069 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(1575128934.186:1927): avc: denied { net_admin } for pid=2069 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(1575128934.186:1928): avc: denied { net_admin } for pid=2068 comm="syz-executor.1" 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(1575128934.196:1929): avc: denied { net_admin } for pid=2069 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(1575128934.196:1930): avc: denied { net_admin } for pid=2069 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(1575128934.196:1931): avc: denied { net_admin } for pid=2069 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(1575128934.196:1932): avc: denied { net_admin } for pid=2073 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(1575128934.196:1934): avc: denied { net_admin } for pid=2073 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 binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 12, process died. binder: undelivered transaction 11, process died. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=384 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 netlink: 34 bytes leftover after parsing attributes in process `syz-executor.1'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7654 comm=syz-executor.1 binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 15, process died. binder: undelivered transaction 14, process died. binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 18, process died. binder: undelivered transaction 17, process died. binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 21, process died. binder: undelivered transaction 20, process died. binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 24, process died. binder: undelivered transaction 23, process died. netlink: 34 bytes leftover after parsing attributes in process `syz-executor.1'. binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 27, process died. binder: undelivered transaction 26, process died. binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 30, process died. binder: undelivered transaction 29, process died. binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 33, process died. binder: undelivered transaction 32, process died. binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 36, process died. binder: undelivered transaction 35, process died. netlink: 34 bytes leftover after parsing attributes in process `syz-executor.1'. binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 39, process died. binder: undelivered transaction 38, process died. audit_printk_skb: 2103 callbacks suppressed audit: type=1400 audit(1575128939.376:2635): avc: denied { sys_admin } for pid=2072 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(1575128939.416:2636): avc: denied { sys_admin } for pid=2072 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(1575128939.446:2637): avc: denied { sys_admin } for pid=2072 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(1575128939.466:2638): avc: denied { sys_admin } for pid=2072 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(1575128939.496:2639): avc: denied { net_admin } for pid=2072 comm="syz-executor.2" 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(1575128939.526:2640): avc: denied { net_admin } for pid=2072 comm="syz-executor.2" 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(1575128939.556:2641): avc: denied { net_admin } for pid=2072 comm="syz-executor.2" 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(1575128939.576:2642): avc: denied { net_admin } for pid=2072 comm="syz-executor.2" 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(1575128939.606:2643): avc: denied { net_admin } for pid=2072 comm="syz-executor.2" 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(1575128939.626:2644): avc: denied { net_admin } for pid=2072 comm="syz-executor.2" 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 ip6_tunnel: ip6tnl1 xmit: Local address not yet configured! selinux_nlmsg_perm: 135 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=384 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 netlink: 34 bytes leftover after parsing attributes in process `syz-executor.1'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 binder: undelivered TRANSACTION_COMPLETE binder: undelivered TRANSACTION_COMPLETE binder: undelivered transaction 42, process died. binder: undelivered transaction 41, process died. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=7807 comm=syz-executor.1