================================================================== BUG: KASAN: use-after-free in __xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2019 [inline] BUG: KASAN: use-after-free in xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2053 [inline] BUG: KASAN: use-after-free in xfrm_policy_lookup_bytype+0xd27/0xdb0 net/xfrm/xfrm_policy.c:2113 Read of size 4 at addr ffff888063cefbb4 by task syz-executor4/29543 CPU: 1 PID: 29543 Comm: syz-executor4 Not tainted 5.0.0-rc2+ #29 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:134 __xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2019 [inline] xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2053 [inline] xfrm_policy_lookup_bytype+0xd27/0xdb0 net/xfrm/xfrm_policy.c:2113 xfrm_policy_lookup+0x7e/0x90 net/xfrm/xfrm_policy.c:2145 xfrm_bundle_lookup net/xfrm/xfrm_policy.c:2939 [inline] xfrm_lookup_with_ifid+0x8cf/0x2a90 net/xfrm/xfrm_policy.c:3080 xfrm_lookup net/xfrm/xfrm_policy.c:3172 [inline] xfrm_lookup_route+0x3b/0x1f0 net/xfrm/xfrm_policy.c:3183 ip_route_output_flow+0xad/0xc0 net/ipv4/route.c:2582 ip_route_connect include/net/route.h:309 [inline] __ip4_datagram_connect+0x7ae/0x1330 net/ipv4/datagram.c:51 ip4_datagram_connect+0x30/0x50 net/ipv4/datagram.c:92 inet_dgram_connect+0x150/0x2e0 net/ipv4/af_inet.c:571 __sys_connect+0x357/0x490 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa8bbd6dc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099 RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000005 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa8bbd6e6d4 R13: 00000000004be4ea R14: 00000000004cea38 R15: 00000000ffffffff Allocated by task 28330: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_kmalloc mm/kasan/common.c:496 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504 __do_kmalloc_node mm/slab.c:3673 [inline] __kmalloc_node_track_caller+0x4e/0x70 mm/slab.c:3687 __kmalloc_reserve.isra.0+0x40/0xe0 net/core/skbuff.c:140 __alloc_skb+0x12d/0x730 net/core/skbuff.c:208 alloc_skb include/linux/skbuff.h:1011 [inline] alloc_skb_with_frags+0xef/0x720 net/core/skbuff.c:5283 sock_alloc_send_pskb+0x8c9/0xad0 net/core/sock.c:2091 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2108 __ip6_append_data.isra.0+0x2556/0x3f20 net/ipv6/ip6_output.c:1443 ip6_make_skb+0x391/0x5f0 net/ipv6/ip6_output.c:1806 udpv6_sendmsg+0x2b56/0x3570 net/ipv6/udp.c:1468 inet_sendmsg+0x1af/0x740 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x409/0x910 net/socket.c:2116 __sys_sendmmsg+0x246/0x730 net/socket.c:2211 __do_sys_sendmmsg net/socket.c:2240 [inline] __se_sys_sendmmsg net/socket.c:2237 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2237 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9: save_stack+0x45/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466 __cache_free mm/slab.c:3487 [inline] kfree+0xcf/0x230 mm/slab.c:3806 skb_free_head+0x93/0xb0 net/core/skbuff.c:553 skb_release_data+0x6ea/0x970 net/core/skbuff.c:573 skb_release_all+0x4d/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] kfree_skb net/core/skbuff.c:659 [inline] kfree_skb+0x199/0x580 net/core/skbuff.c:653 __udp6_lib_mcast_deliver net/ipv6/udp.c:815 [inline] __udp6_lib_rcv+0x22b9/0x30d0 net/ipv6/udp.c:916 udpv6_rcv+0x22/0x30 net/ipv6/udp.c:1026 ip6_protocol_deliver_rcu+0x3aa/0x1940 net/ipv6/ip6_input.c:394 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ip6_input+0xf9/0x600 net/ipv6/ip6_input.c:443 ip6_mc_input+0x4f9/0x10d0 net/ipv6/ip6_input.c:537 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x177/0x330 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:289 [inline] NF_HOOK include/linux/netfilter.h:283 [inline] ipv6_rcv+0x113/0x650 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x160/0x210 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1c0 net/core/dev.c:5083 process_backlog+0x206/0x750 net/core/dev.c:5923 napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x76d/0x1930 net/core/dev.c:6412 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 The buggy address belongs to the object at ffff888063cefb00 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 180 bytes inside of 1024-byte region [ffff888063cefb00, ffff888063ceff00) The buggy address belongs to the page: page:ffffea00018f3b80 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0xffff888063cee900 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea000264f908 ffffea0001a03e88 ffff88812c3f0ac0 raw: ffff888063cee900 ffff888063cee000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888063cefa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888063cefb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888063cefb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888063cefc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888063cefc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ downgrading a read lock WARNING: CPU: 1 PID: 29537 at kernel/locking/lockdep.c:3553 __lock_downgrade kernel/locking/lockdep.c:3553 [inline] WARNING: CPU: 1 PID: 29537 at kernel/locking/lockdep.c:3553 lock_downgrade+0x4d2/0x910 kernel/locking/lockdep.c:3816