audit: type=1400 audit(1558707491.611:3473): avc: denied { create } for pid=31604 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 ====================================================== [ INFO: possible circular locking dependency detected ] 4.4.174+ #17 Not tainted ------------------------------------------------------- syz-executor.3/31611 is trying to acquire lock: (rtnl_mutex){+.+.+.}, at: [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 but task is already holding lock: (sk_lock-AF_INET6){+.+.+.}, at: [] lock_sock include/net/sock.h:1497 [inline] (sk_lock-AF_INET6){+.+.+.}, at: [] do_ipv6_setsockopt.isra.0+0x28a/0x30c0 net/ipv6/ipv6_sockglue.c:166 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: [] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592 [] lock_sock_nested+0xc6/0x120 net/core/sock.c:2463 [] lock_sock include/net/sock.h:1497 [inline] [] do_ipv6_setsockopt.isra.0+0x2eba/0x30c0 net/ipv6/ipv6_sockglue.c:166 [] compat_ipv6_setsockopt net/ipv6/ipv6_sockglue.c:935 [inline] [] compat_ipv6_setsockopt+0xe7/0x1d0 net/ipv6/ipv6_sockglue.c:916 [] inet_csk_compat_setsockopt+0x99/0x120 net/ipv4/inet_connection_sock.c:914 [] compat_tcp_setsockopt+0x40/0x70 net/ipv4/tcp.c:2654 [] compat_sock_common_setsockopt+0xb4/0x150 net/core/sock.c:2674 [] C_SYSC_setsockopt net/compat.c:385 [inline] [] compat_SyS_setsockopt+0x15c/0x720 net/compat.c:368 [] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] [] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397 [] sysenter_flags_fixed+0xd/0x1a [] check_prev_add kernel/locking/lockdep.c:1853 [inline] [] check_prevs_add kernel/locking/lockdep.c:1958 [inline] [] validate_chain kernel/locking/lockdep.c:2144 [inline] [] __lock_acquire+0x37d6/0x4f50 kernel/locking/lockdep.c:3213 [] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592 [] __mutex_lock_common kernel/locking/mutex.c:521 [inline] [] mutex_lock_nested+0xc1/0xb80 kernel/locking/mutex.c:621 [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 [] ipv6_sock_mc_close+0x10e/0x350 net/ipv6/mcast.c:288 [] do_ipv6_setsockopt.isra.0+0x1bd1/0x30c0 net/ipv6/ipv6_sockglue.c:202 [] compat_ipv6_setsockopt net/ipv6/ipv6_sockglue.c:935 [inline] [] compat_ipv6_setsockopt+0xe7/0x1d0 net/ipv6/ipv6_sockglue.c:916 [] compat_udpv6_setsockopt+0x4e/0x90 net/ipv6/udp.c:1446 [] compat_sock_common_setsockopt+0xb4/0x150 net/core/sock.c:2674 [] C_SYSC_setsockopt net/compat.c:385 [inline] [] compat_SyS_setsockopt+0x15c/0x720 net/compat.c:368 [] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] [] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397 [] sysenter_flags_fixed+0xd/0x1a other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_INET6); lock(rtnl_mutex); lock(sk_lock-AF_INET6); lock(rtnl_mutex); *** DEADLOCK *** 1 lock held by syz-executor.3/31611: #0: (sk_lock-AF_INET6){+.+.+.}, at: [] lock_sock include/net/sock.h:1497 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [] do_ipv6_setsockopt.isra.0+0x28a/0x30c0 net/ipv6/ipv6_sockglue.c:166 stack backtrace: CPU: 1 PID: 31611 Comm: syz-executor.3 Not tainted 4.4.174+ #17 0000000000000000 cb09dcdc6434fc4a ffff8801a8ecf540 ffffffff81aad1a1 ffffffff84057a80 ffff8800a202c740 ffffffff83a8db50 ffffffff83acc760 ffffffff83a8db50 ffff8801a8ecf590 ffffffff813abcda ffff8801a8ecf670 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] print_circular_bug.cold+0x2f7/0x44e kernel/locking/lockdep.c:1226 [] check_prev_add kernel/locking/lockdep.c:1853 [inline] [] check_prevs_add kernel/locking/lockdep.c:1958 [inline] [] validate_chain kernel/locking/lockdep.c:2144 [inline] [] __lock_acquire+0x37d6/0x4f50 kernel/locking/lockdep.c:3213 [] lock_acquire+0x15e/0x450 kernel/locking/lockdep.c:3592 [] __mutex_lock_common kernel/locking/mutex.c:521 [inline] [] mutex_lock_nested+0xc1/0xb80 kernel/locking/mutex.c:621 [] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70 [] ipv6_sock_mc_close+0x10e/0x350 net/ipv6/mcast.c:288 [] do_ipv6_setsockopt.isra.0+0x1bd1/0x30c0 net/ipv6/ipv6_sockglue.c:202 [] compat_ipv6_setsockopt net/ipv6/ipv6_sockglue.c:935 [inline] [] compat_ipv6_setsockopt+0xe7/0x1d0 net/ipv6/ipv6_sockglue.c:916 [] compat_udpv6_setsockopt+0x4e/0x90 net/ipv6/udp.c:1446 [] compat_sock_common_setsockopt+0xb4/0x150 net/core/sock.c:2674 [] C_SYSC_setsockopt net/compat.c:385 [inline] [] compat_SyS_setsockopt+0x15c/0x720 net/compat.c:368 [] do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] [] do_fast_syscall_32+0x32d/0xa90 arch/x86/entry/common.c:397 [] sysenter_flags_fixed+0xd/0x1a audit: type=1400 audit(1558707492.331:3474): avc: denied { create } for pid=31604 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707492.371:3475): avc: denied { write } for pid=31604 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707492.511:3476): avc: denied { create } for pid=31604 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707492.561:3477): avc: denied { create } for pid=31604 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707492.591:3478): avc: denied { write } for pid=31604 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707493.171:3479): avc: denied { create } for pid=31647 comm="syz-executor.2" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 keychord: invalid keycode count 0 keychord: Insufficient bytes present for keycount 0 keychord: unsupported version 40 keychord: invalid keycode count 0 keychord: Insufficient bytes present for keycount 0 audit_printk_skb: 45 callbacks suppressed audit: type=1400 audit(1558707496.101:3495): avc: denied { create } for pid=31730 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707496.191:3496): avc: denied { create } for pid=31730 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707496.341:3497): avc: denied { write } for pid=31730 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707496.381:3498): avc: denied { create } for pid=31737 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_fib_lookup_socket permissive=1 audit: type=1400 audit(1558707496.391:3499): avc: denied { write } for pid=31730 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707496.511:3500): avc: denied { create } for pid=31744 comm="syz-executor.1" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707496.551:3501): avc: denied { read } for pid=31730 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707496.581:3502): avc: denied { write } for pid=31744 comm="syz-executor.1" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707496.641:3503): avc: denied { read } for pid=31730 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707496.731:3504): avc: denied { create } for pid=31730 comm="syz-executor.4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 binder: 31791:31796 transaction failed 29189/-22, size 0-0 line 3014 binder: undelivered TRANSACTION_ERROR: 29189 binder: 31791:31796 transaction failed 29189/-22, size 0-0 line 3014 binder: undelivered TRANSACTION_ERROR: 29189 audit_printk_skb: 228 callbacks suppressed audit: type=1400 audit(1558707501.361:3581): avc: denied { create } for pid=31892 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707501.431:3582): avc: denied { create } for pid=31892 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707501.481:3583): avc: denied { create } for pid=31892 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707501.561:3584): avc: denied { ioctl } for pid=31892 comm="syz-executor.3" path="socket:[101254]" dev="sockfs" ino=101254 ioctlcmd=8933 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707501.611:3585): avc: denied { ioctl } for pid=31892 comm="syz-executor.3" path="socket:[101254]" dev="sockfs" ino=101254 ioctlcmd=8933 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707501.621:3586): avc: denied { write } for pid=31892 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 audit: type=1400 audit(1558707501.641:3587): avc: denied { write } for pid=31892 comm="syz-executor.3" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1