xt_nfacct: accounting object `syz1' does not exists ================================================================== BUG: KASAN: use-after-free in __write_once_size include/linux/compiler.h:218 [inline] BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:702 [inline] BUG: KASAN: use-after-free in hlist_del_init include/linux/list.h:717 [inline] BUG: KASAN: use-after-free in __xfrm_policy_unlink+0x977/0xa00 net/xfrm/xfrm_policy.c:2213 Write of size 8 at addr ffff888093019ee8 by task syz-executor4/6889 CPU: 1 PID: 6889 Comm: syz-executor4 Not tainted 5.0.0-rc2+ #10 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_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:140 __write_once_size include/linux/compiler.h:218 [inline] __hlist_del include/linux/list.h:702 [inline] hlist_del_init include/linux/list.h:717 [inline] __xfrm_policy_unlink+0x977/0xa00 net/xfrm/xfrm_policy.c:2213 xfrm_policy_flush+0x331/0x460 net/xfrm/xfrm_policy.c:1789 xfrm_flush_policy+0x166/0x470 net/xfrm/xfrm_user.c:2129 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: 0033:0x458099 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:00007f11439cbc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000006 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f11439cc6d4 R13: 00000000004c562b R14: 00000000004d9298 R15: 00000000ffffffff Allocated by task 6021: 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 mm/slab.c:3711 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3720 kmalloc include/linux/slab.h:550 [inline] kzalloc include/linux/slab.h:740 [inline] l2tp_session_create+0xa5/0xae0 net/l2tp/l2tp_core.c:1644 pppol2tp_connect+0x1865/0x2f00 net/l2tp/l2tp_ppp.c:782 __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 Freed by task 0: 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 l2tp_session_free+0x193/0x290 net/l2tp/l2tp_core.c:1570 l2tp_session_dec_refcount net/l2tp/l2tp_core.h:260 [inline] pppol2tp_session_destruct+0xf5/0x130 net/l2tp/l2tp_ppp.c:428 __sk_destruct+0xd2/0xa60 net/core/sock.c:1595 sk_destruct+0x7b/0x90 net/core/sock.c:1630 __sk_free+0xce/0x300 net/core/sock.c:1641 sk_free+0x42/0x50 net/core/sock.c:1652 sock_put include/net/sock.h:1707 [inline] pppol2tp_put_sk+0x61/0x80 net/l2tp/l2tp_ppp.c:412 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2452 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2773 [inline] rcu_process_callbacks+0xc4a/0x1680 kernel/rcu/tree.c:2754 __do_softirq+0x30b/0xb11 kernel/softirq.c:292 The buggy address belongs to the object at ffff888093019b40 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 936 bytes inside of 1024-byte region [ffff888093019b40, ffff888093019f40) The buggy address belongs to the page: page:ffffea00024c0600 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0xffff888093018940 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001aa7d08 ffffea00020e9a08 ffff88812c3f0ac0 raw: ffff888093018940 ffff888093018040 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888093019d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888093019e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888093019e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888093019f00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888093019f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================