random: sshd: uninitialized urandom read (32 bytes read) random: crng init done audit: type=1400 audit(1561620690.851:5): avc: denied { associate } for pid=2083 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.0/2231: #0: (rcu_read_lock_bh){......}, at: [<00000000ccdbd4eb>] ip_finish_output2+0x20b/0x1280 net/ipv4/ip_output.c:198 #1: (rcu_read_lock_bh){......}, at: [<000000006ddc5fc4>] __dev_queue_xmit+0x1d4/0x1bd0 net/core/dev.c:3407 #2: (_xmit_TUNNEL6#2){+.....}, at: [<00000000187718e2>] spin_lock include/linux/spinlock.h:302 [inline] #2: (_xmit_TUNNEL6#2){+.....}, at: [<00000000187718e2>] __netif_tx_lock include/linux/netdevice.h:3573 [inline] #2: (_xmit_TUNNEL6#2){+.....}, at: [<00000000187718e2>] __dev_queue_xmit+0x1116/0x1bd0 net/core/dev.c:3469 #3: (slock-AF_INET){+.-...}, at: [<000000005d989347>] spin_trylock include/linux/spinlock.h:312 [inline] #3: (slock-AF_INET){+.-...}, at: [<000000005d989347>] icmp_xmit_lock net/ipv4/icmp.c:220 [inline] #3: (slock-AF_INET){+.-...}, at: [<000000005d989347>] __icmp_send+0x48b/0x1420 net/ipv4/icmp.c:656 stack backtrace: CPU: 0 PID: 2231 Comm: syz-executor.0 Not tainted 4.9.183+ #4 ffff8801cb5fedd8 ffffffff81b580a1 ffff8801ce403140 0000000000000000 0000000000000002 00000000000000cd ffff8801cb43af80 ffff8801cb5fee08 ffffffff81404fb9 ffff8801ce403198 ffff8801cb5fef28 ffff8801d9d2d500 Call Trace: [<000000007032fe5a>] __dump_stack lib/dump_stack.c:15 [inline] [<000000007032fe5a>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<00000000ecc78a3e>] lockdep_rcu_suspicious.cold+0x10a/0x149 kernel/locking/lockdep.c:4455 [<0000000092ab2c65>] __in_dev_get_rcu include/linux/inetdevice.h:205 [inline] [<0000000092ab2c65>] fib_compute_spec_dst+0x6c4/0xcc0 net/ipv4/fib_frontend.c:284 [<00000000ea84113e>] __ip_options_echo+0x4be/0x13e0 net/ipv4/ip_options.c:177 [<0000000059bf97da>] __icmp_send+0x648/0x1420 net/ipv4/icmp.c:685 [<00000000b145774d>] ipv4_send_dest_unreach net/ipv4/route.c:1202 [inline] [<00000000b145774d>] ipv4_link_failure+0x460/0x850 net/ipv4/route.c:1209 [<00000000898f6e02>] dst_link_failure include/net/dst.h:490 [inline] [<00000000898f6e02>] vti6_xmit net/ipv6/ip6_vti.c:522 [inline] [<00000000898f6e02>] vti6_tnl_xmit+0xb08/0x17f0 net/ipv6/ip6_vti.c:561 [<00000000ef8c27d6>] __netdev_start_xmit include/linux/netdevice.h:4072 [inline] [<00000000ef8c27d6>] netdev_start_xmit include/linux/netdevice.h:4081 [inline] [<00000000ef8c27d6>] xmit_one net/core/dev.c:2977 [inline] [<00000000ef8c27d6>] dev_hard_start_xmit+0x195/0x8b0 net/core/dev.c:2993 [<00000000b15e9d53>] __dev_queue_xmit+0x11a3/0x1bd0 net/core/dev.c:3473 [<00000000a027ea9b>] dev_queue_xmit+0x18/0x20 net/core/dev.c:3506 [<00000000b4873a12>] neigh_direct_output+0x16/0x20 net/core/neighbour.c:1366 [<00000000442d4da8>] dst_neigh_output include/net/dst.h:470 [inline] [<00000000442d4da8>] ip_finish_output2+0x6a2/0x1280 net/ipv4/ip_output.c:225 [<00000000d1411312>] ip_finish_output+0x3c4/0xce0 net/ipv4/ip_output.c:313 [<0000000009b1faf0>] NF_HOOK_COND include/linux/netfilter.h:246 [inline] [<0000000009b1faf0>] ip_output+0x1ec/0x5b0 net/ipv4/ip_output.c:401 [<00000000a8261868>] dst_output include/net/dst.h:507 [inline] [<00000000a8261868>] NF_HOOK_THRESH include/linux/netfilter.h:232 [inline] [<00000000a8261868>] NF_HOOK include/linux/netfilter.h:255 [inline] [<00000000a8261868>] raw_send_hdrinc net/ipv4/raw.c:421 [inline] [<00000000a8261868>] raw_sendmsg+0x1c5c/0x23e0 net/ipv4/raw.c:643 [<000000006ecd9e86>] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:766 [<0000000086d9c3a0>] sock_sendmsg_nosec net/socket.c:649 [inline] [<0000000086d9c3a0>] sock_sendmsg+0xbe/0x110 net/socket.c:659 [<00000000391b0a7c>] sock_write_iter+0x235/0x3d0 net/socket.c:857 [<000000002d3a178d>] new_sync_write fs/read_write.c:498 [inline] [<000000002d3a178d>] __vfs_write+0x3c1/0x560 fs/read_write.c:511 [<00000000b03f2fad>] vfs_write+0x185/0x520 fs/read_write.c:559 [<000000007a873696>] SYSC_write fs/read_write.c:607 [inline] [<000000007a873696>] SyS_write+0x121/0x270 fs/read_write.c:599