random: sshd: uninitialized urandom read (32 bytes read) audit: type=1400 audit(1552224420.658:7): avc: denied { map } for pid=1785 comm="syz-executor103" path="/root/syz-executor103657884" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 netlink: 8 bytes leftover after parsing attributes in process `syz-executor103'. ============================= WARNING: suspicious RCU usage 4.14.105+ #29 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1590 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 4 locks held by syz-executor103/1786: #0: (rtnl_mutex){+.+.}, at: [] tun_detach drivers/net/tun.c:585 [inline] #0: (rtnl_mutex){+.+.}, at: [] tun_chr_close+0x34/0x60 drivers/net/tun.c:2661 #1: (&(&net->ipv6.fib6_gc_lock)->rlock){+...}, at: [] spin_trylock_bh include/linux/spinlock.h:377 [inline] #1: (&(&net->ipv6.fib6_gc_lock)->rlock){+...}, at: [] fib6_run_gc+0x1ff/0x2a0 net/ipv6/ip6_fib.c:1939 #2: (rcu_read_lock){....}, at: [] __fib6_clean_all+0x0/0x230 net/ipv6/ip6_fib.c:1823 #3: (&tb->tb6_lock){++..}, at: [] __fib6_clean_all+0xde/0x230 net/ipv6/ip6_fib.c:1837 stack backtrace: CPU: 0 PID: 1786 Comm: syz-executor103 Not tainted 4.14.105+ #29 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 fib6_del+0x8c2/0xbe0 net/ipv6/ip6_fib.c:1590 fib6_clean_node+0x270/0x440 net/ipv6/ip6_fib.c:1777 fib6_walk_continue+0x3a5/0x5f0 net/ipv6/ip6_fib.c:1703 fib6_walk+0x8d/0xe0 net/ipv6/ip6_fib.c:1748 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:1822 __fib6_clean_all+0xf5/0x230 net/ipv6/ip6_fib.c:1838 fib6_clean_all net/ipv6/ip6_fib.c:1849 [inline] fib6_run_gc+0x104/0x2a0 net/ipv6/ip6_fib.c:1947 ndisc_netdev_event+0x32b/0x3d0 net/ipv6/ndisc.c:1779 notifier_call_chain+0x10c/0x1a0 kernel/notifier.c:93