random: sshd: uninitialized urandom read (32 bytes read, 99 bits of entropy available) random: sshd: uninitialized urandom read (32 bytes read, 103 bits of entropy available) random: sshd: uninitialized urandom read (32 bytes read, 112 bits of entropy available) ================================================================== 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 ffff8800b61d2658 by task syzkaller610588/3779 CPU: 0 PID: 3779 Comm: syzkaller610588 Not tainted 4.4.119-g024f962 #26 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 8677f3bc780bc4d7 ffff8801c4e3f7e0 ffffffff81d0402d ffffea0002d87480 ffff8800b61d2658 0000000000000000 ffff8800b61d2658 0000000000000040 ffff8801c4e3f818 ffffffff814fe103 ffff8800b61d2658 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 3762: [] 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 0: [] 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 ffff8800b61d2640 which belongs to the cache ip_dst_cache of size 208 The buggy address is located 24 bytes inside of 208-byte region [ffff8800b61d2640, ffff8800b61d2710) The buggy address belongs to the page: PANIC: double fault, error_code: 0x0 CPU: 0 PID: 3779 Comm: syzkaller610588 Not tainted 4.4.119-g024f962 #26 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801c6b6e000 task.stack: ffff8801c4e38000 RIP: 0010:[] [] dump_page_badflags+0x4/0x250 mm/debug.c:84 RSP: 0018:ffff880100000000 EFLAGS: 00010046 RAX: ffff8801c6b6e000 RBX: ffffea0002d87480 RCX: ffffffff81490970 RDX: 0000000000000000 RSI: ffffffff838a9060 RDI: ffffea0002d87480 RBP: ffff880100000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000002 R11: fffffbfff0ad7e1e R12: 0000000000000000 R13: ffffffff838a9060 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000001513880(0063) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8800fffffff8 CR3: 00000001c97ee000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: Call Trace: Code: e8 92 df 06 00 e9 83 fd ff ff e8 88 df 06 00 e9 50 fd ff ff e8 7e df 06 00 e9 1d fd ff ff 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 <41> 57 41 56 41 55 49 89 f5 41 54 49 89 d4 53 48 89 fb 48 83 ec