================================================================== BUG: KASAN: use-after-free in __xfrm_policy_bysel_ctx.constprop.0+0x3e5/0x470 net/xfrm/xfrm_policy.c:1618 Read of size 1 at addr ffff8880a7949d19 by task syz-executor1/26691 CPU: 0 PID: 26691 Comm: syz-executor1 Not tainted 4.20.0+ #3 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:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 __xfrm_policy_bysel_ctx.constprop.0+0x3e5/0x470 net/xfrm/xfrm_policy.c:1618 xfrm_policy_bysel_ctx+0x944/0x1020 net/xfrm/xfrm_policy.c:1664 xfrm_get_policy+0x67b/0x1160 net/xfrm/xfrm_user.c:1887 xfrm_user_rcv_msg+0x458/0x8d0 net/xfrm/xfrm_user.c:2663 netlink_rcv_skb+0x17d/0x410 net/netlink/af_netlink.c:2477 xfrm_netlink_rcv+0x70/0x90 net/xfrm/xfrm_user.c:2671 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x574/0x770 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa05/0xf90 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x7ec/0x910 net/socket.c:2116 __sys_sendmsg+0x112/0x270 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 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:00007f250eb32c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f250eb336d4 R13: 00000000004c5394 R14: 00000000004d8e30 R15: 00000000ffffffff Allocated by task 26671: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 __do_kmalloc_node mm/slab.c:3684 [inline] __kmalloc_node_track_caller+0x51/0x80 mm/slab.c:3698 __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] nlmsg_new include/net/netlink.h:654 [inline] inet6_rt_notify+0x101/0x2c0 net/ipv6/route.c:4974 fib6_del_route net/ipv6/ip6_fib.c:1813 [inline] fib6_del+0xf26/0x12e0 net/ipv6/ip6_fib.c:1840 kernel msg: ebtables bug: please report to author: bad policy __ip6_del_rt+0xa2/0x140 net/ipv6/route.c:3143 ip6_del_rt+0x106/0x160 net/ipv6/route.c:3155 __ipv6_dev_ac_dec+0x29b/0x3e0 net/ipv6/anycast.c:371 ipv6_dev_ac_dec net/ipv6/anycast.c:384 [inline] ipv6_sock_ac_close+0x337/0x4b0 net/ipv6/anycast.c:214 inet6_release+0x4b/0x80 net/ipv6/af_inet6.c:456 __sock_release+0xd3/0x250 net/socket.c:579 sock_close+0x1b/0x30 net/socket.c:1141 __fput+0x3c5/0xaf0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x696/0x800 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 26671: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 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] consume_skb net/core/skbuff.c:701 [inline] consume_skb+0x18c/0x550 net/core/skbuff.c:695 netlink_broadcast_filtered+0x6e7/0x16f0 net/netlink/af_netlink.c:1512 netlink_broadcast net/netlink/af_netlink.c:1534 [inline] nlmsg_multicast include/net/netlink.h:734 [inline] nlmsg_notify+0x93/0x1c0 net/netlink/af_netlink.c:2520 rtnl_notify+0xc5/0xf0 net/core/rtnetlink.c:742 inet6_rt_notify+0x204/0x2c0 net/ipv6/route.c:4986 fib6_del_route net/ipv6/ip6_fib.c:1813 [inline] fib6_del+0xf26/0x12e0 net/ipv6/ip6_fib.c:1840 __ip6_del_rt+0xa2/0x140 net/ipv6/route.c:3143 ip6_del_rt+0x106/0x160 net/ipv6/route.c:3155 __ipv6_dev_ac_dec+0x29b/0x3e0 net/ipv6/anycast.c:371 ipv6_dev_ac_dec net/ipv6/anycast.c:384 [inline] ipv6_sock_ac_close+0x337/0x4b0 net/ipv6/anycast.c:214 inet6_release+0x4b/0x80 net/ipv6/af_inet6.c:456 __sock_release+0xd3/0x250 net/socket.c:579 sock_close+0x1b/0x30 net/socket.c:1141 __fput+0x3c5/0xaf0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x32a/0x3b0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x696/0x800 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a7949b00 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 537 bytes inside of 1024-byte region [ffff8880a7949b00, ffff8880a7949f00) The buggy address belongs to the page: page:ffffea00029e5200 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002569888 ffffea0002637588 ffff88812c3f0ac0 raw: 0000000000000000 ffff8880a7948000 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a7949c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a7949c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a7949d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a7949d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a7949e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================