audit: type=1400 audit(1561602079.997:5): avc: denied { associate } for pid=2081 comm="syz-executor.0" name="syz0" scontext=unconfined_u:object_r:unlabeled_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 =============================== [ INFO: suspicious RCU usage. ] 4.9.183+ #4 Not tainted ------------------------------- ./include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 0 4 locks held by syz-executor.0/2229: #0: (rcu_read_lock_bh){......}, at: [<0000000075cc5daf>] ip_finish_output2+0x20b/0x1280 net/ipv4/ip_output.c:198 #1: (rcu_read_lock_bh){......}, at: [<00000000449b7a1e>] __dev_queue_xmit+0x1d4/0x1bd0 net/core/dev.c:3407 #2: (_xmit_TUNNEL6#2){+.....}, at: [<00000000129f24b2>] spin_lock include/linux/spinlock.h:302 [inline] #2: (_xmit_TUNNEL6#2){+.....}, at: [<00000000129f24b2>] __netif_tx_lock include/linux/netdevice.h:3573 [inline] #2: (_xmit_TUNNEL6#2){+.....}, at: [<00000000129f24b2>] __dev_queue_xmit+0x1116/0x1bd0 net/core/dev.c:3469 #3: (slock-AF_INET){+.-...}, at: [<00000000773f0318>] spin_trylock include/linux/spinlock.h:312 [inline] #3: (slock-AF_INET){+.-...}, at: [<00000000773f0318>] icmp_xmit_lock net/ipv4/icmp.c:220 [inline] #3: (slock-AF_INET){+.-...}, at: [<00000000773f0318>] __icmp_send+0x48b/0x1420 net/ipv4/icmp.c:656 stack backtrace: CPU: 1 PID: 2229 Comm: syz-executor.0 Not tainted 4.9.183+ #4 ffff8801cbb06dd8 ffffffff81b580a1 ffff8801d036e500 0000000000000000 0000000000000002 00000000000000cd ffff8801cc3f4740 ffff8801cbb06e08 ffffffff81404fb9 ffff8801d036e558 ffff8801cbb06f28 ffff8801d9d5c400 Call Trace: [<0000000014b87cc2>] __dump_stack lib/dump_stack.c:15 [inline] [<0000000014b87cc2>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<00000000d3382124>] lockdep_rcu_suspicious.cold+0x10a/0x149 kernel/locking/lockdep.c:4455 [<00000000c766ca0e>] __in_dev_get_rcu include/linux/inetdevice.h:205 [inline] [<00000000c766ca0e>] fib_compute_spec_dst+0x6c4/0xcc0 net/ipv4/fib_frontend.c:284 [<000000007a85cc90>] __ip_options_echo+0x4be/0x13e0 net/ipv4/ip_options.c:177 [<000000005dcdf219>] __icmp_send+0x648/0x1420 net/ipv4/icmp.c:685 [<00000000fec474fc>] ipv4_send_dest_unreach net/ipv4/route.c:1202 [inline] [<00000000fec474fc>] ipv4_link_failure+0x460/0x850 net/ipv4/route.c:1209 [<00000000a309e321>] dst_link_failure include/net/dst.h:490 [inline] [<00000000a309e321>] vti6_xmit net/ipv6/ip6_vti.c:522 [inline] [<00000000a309e321>] vti6_tnl_xmit+0xb08/0x17f0 net/ipv6/ip6_vti.c:561 [<00000000bc0c3b64>] __netdev_start_xmit include/linux/netdevice.h:4072 [inline] [<00000000bc0c3b64>] netdev_start_xmit include/linux/netdevice.h:4081 [inline] [<00000000bc0c3b64>] xmit_one net/core/dev.c:2977 [inline] [<00000000bc0c3b64>] dev_hard_start_xmit+0x195/0x8b0 net/core/dev.c:2993 [<00000000394e35f1>] __dev_queue_xmit+0x11a3/0x1bd0 net/core/dev.c:3473 [<0000000097476257>] dev_queue_xmit+0x18/0x20 net/core/dev.c:3506 [<0000000074c66f94>] neigh_direct_output+0x16/0x20 net/core/neighbour.c:1366 [<0000000034b80a8e>] dst_neigh_output include/net/dst.h:470 [inline] [<0000000034b80a8e>] ip_finish_output2+0x6a2/0x1280 net/ipv4/ip_output.c:225 [<0000000066ec9c4a>] ip_finish_output+0x3c4/0xce0 net/ipv4/ip_output.c:313 [<0000000042788dd6>] NF_HOOK_COND include/linux/netfilter.h:246 [inline] [<0000000042788dd6>] ip_output+0x1ec/0x5b0 net/ipv4/ip_output.c:401 [<0000000076676432>] dst_output include/net/dst.h:507 [inline] [<0000000076676432>] NF_HOOK_THRESH include/linux/netfilter.h:232 [inline] [<0000000076676432>] NF_HOOK include/linux/netfilter.h:255 [inline] [<0000000076676432>] raw_send_hdrinc net/ipv4/raw.c:421 [inline] [<0000000076676432>] raw_sendmsg+0x1c5c/0x23e0 net/ipv4/raw.c:643 [<000000005e9952ae>] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:766 [<000000009870ea2f>] sock_sendmsg_nosec net/socket.c:649 [inline] [<000000009870ea2f>] sock_sendmsg+0xbe/0x110 net/socket.c:659 [<000000003f5632b0>] sock_write_iter+0x235/0x3d0 net/socket.c:857 [<0000000027c20369>] new_sync_write fs/read_write.c:498 [inline] [<0000000027c20369>] __vfs_write+0x3c1/0x560 fs/read_write.c:511 [<00000000b86821dd>] vfs_write+0x185/0x520 fs/read_write.c:559 [<00000000e2af2cee>] SYSC_write fs/read_write.c:607 [inline] [<00000000e2af2cee>] SyS_write+0x121/0x270 fs/read_write.c:599