random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) random: sshd: uninitialized urandom read (32 bytes read, 40 bits of entropy available) random: nonblocking pool is initialized ================================================================== BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:141 [inline] BUG: KASAN: use-after-free in ip6_xmit+0x1a2c/0x1a70 net/ipv6/ip6_output.c:237 Read of size 8 at addr ffff8801cd478298 by task syzkaller046719/3795 CPU: 1 PID: 3795 Comm: syzkaller046719 Not tainted 4.4.120-gd63fdf6 #28 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 a397086eeb98db17 ffff8800bb0e77e0 ffffffff81d0408d ffffea0007351e00 ffff8801cd478298 0000000000000000 ffff8801cd478298 0000000000000040 ffff8800bb0e7818 ffffffff814fe143 ffff8801cd478298 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_address_description+0x73/0x260 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report+0x285/0x370 mm/kasan/report.c:408 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [] ip6_dst_idev include/net/ip6_fib.h:141 [inline] [] ip6_xmit+0x1a2c/0x1a70 net/ipv6/ip6_output.c:237 [] inet6_csk_xmit+0x246/0x480 net/ipv6/inet6_connection_sock.c:176 [] l2tp_xmit_core net/l2tp/l2tp_core.c:1084 [inline] [] l2tp_xmit_skb+0xc2f/0xea0 net/l2tp/l2tp_core.c:1179 [] pppol2tp_sendmsg+0x584/0x7f0 net/l2tp/l2tp_ppp.c:355 [] sock_sendmsg_nosec net/socket.c:625 [inline] [] sock_sendmsg+0xca/0x110 net/socket.c:635 [] SYSC_sendto+0x2c8/0x340 net/socket.c:1665 [] SyS_sendto+0x40/0x50 net/socket.c:1633 [] entry_SYSCALL_64_fastpath+0x1c/0x98 Allocated by task 3773: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:616 [] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554 [] slab_post_alloc_hook mm/slub.c:1349 [inline] [] slab_alloc_node mm/slub.c:2615 [inline] [] slab_alloc mm/slub.c:2623 [inline] [] kmem_cache_alloc+0xba/0x290 mm/slub.c:2628 [] dst_alloc+0x11f/0x1a0 net/core/dst.c:210 [] rt_dst_alloc+0x78/0x430 net/ipv4/route.c:1467 [] __mkroute_output net/ipv4/route.c:2120 [inline] [] __ip_route_output_key_hash+0xa4e/0x2390 net/ipv4/route.c:2332 [] __ip_route_output_key include/net/route.h:123 [inline] [] ip_route_connect include/net/route.h:296 [inline] [] __ip4_datagram_connect+0xa15/0x1150 net/ipv4/datagram.c:51 [] __ip6_datagram_connect+0x4d9/0x1950 net/ipv6/datagram.c:59 [] ip6_datagram_connect+0x2f/0x50 net/ipv6/datagram.c:223 [] inet_dgram_connect+0x16b/0x1f0 net/ipv4/af_inet.c:550 [] SYSC_connect+0x1b6/0x310 net/socket.c:1557 [] SyS_connect+0x24/0x30 net/socket.c:1538 [] entry_SYSCALL_64_fastpath+0x1c/0x98 Freed by task 14: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kmem_cache_free+0xc7/0x320 mm/slub.c:2881 [] dst_destroy+0x20e/0x330 net/core/dst.c:270 [] dst_destroy_rcu+0x15/0x40 net/core/dst.c:295 [] __rcu_reclaim kernel/rcu/rcu.h:118 [inline] [] rcu_do_batch kernel/rcu/tree.c:2705 [inline] [] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline] [] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline] [] rcu_process_callbacks+0x7f4/0x14a0 kernel/rcu/tree.c:2957 [] __do_softirq+0x227/0xa38 kernel/softirq.c:273 The buggy address belongs to the object at ffff8801cd478280 which belongs to the cache ip_dst_cache of size 208 The buggy address is located 24 bytes inside of 208-byte region [ffff8801cd478280, ffff8801cd478350) The buggy address belongs to the page: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at lib/debugobjects.c:263 debug_print_object+0x17d/0x220 lib/debugobjects.c:260() ODEBUG: deactivate not available (active state 0) object type: hrtimer hint: tick_sched_timer+0x0/0x120 kernel/time/tick-sched.c:124