================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51 Read of size 8 at addr ffff8881ba4b5030 by task kworker/0:2/3434 CPU: 0 PID: 3434 Comm: kworker/0:2 Not tainted 4.20.0-rc6-next-20181210+ #164 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient neigh_periodic_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.4+0x9/0x1ff mm/kasan/report.c:187 kasan_report.cold.5+0x1b/0x39 mm/kasan/report.c:317 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51 __list_del_entry include/linux/list.h:117 [inline] list_del_init include/linux/list.h:159 [inline] neigh_mark_dead+0x13b/0x410 net/core/neighbour.c:125 neigh_periodic_work+0x89a/0xc30 net/core/neighbour.c:905 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Allocated by task 5965: save_stack+0x43/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] kasan_kmalloc+0xcb/0xd0 mm/kasan/common.c:482 __do_kmalloc_node mm/slab.c:3671 [inline] __kmalloc_node_track_caller+0x4d/0x70 mm/slab.c:3685 __kmalloc_reserve.isra.38+0x41/0xe0 net/core/skbuff.c:137 __alloc_skb+0x155/0x770 net/core/skbuff.c:205 alloc_skb_fclone include/linux/skbuff.h:1050 [inline] sk_stream_alloc_skb+0x141/0x970 net/ipv4/tcp.c:874 tcp_sendmsg_locked+0xee1/0x3ee0 net/ipv4/tcp.c:1286 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1443 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 sock_write_iter+0x35e/0x5c0 net/socket.c:901 call_write_iter include/linux/fs.h:1863 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x72c/0xab0 fs/read_write.c:487 vfs_write+0x1fc/0x580 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 5965: save_stack+0x43/0xd0 mm/kasan/common.c:73 set_track mm/kasan/common.c:85 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:444 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452 __cache_free mm/slab.c:3485 [inline] kfree+0xcf/0x230 mm/slab.c:3804 skb_free_head+0x99/0xc0 net/core/skbuff.c:550 skb_release_data+0x70c/0x9a0 net/core/skbuff.c:570 skb_release_all+0x4a/0x60 net/core/skbuff.c:627 __kfree_skb+0x15/0x20 net/core/skbuff.c:641 sk_wmem_free_skb include/net/sock.h:1458 [inline] tcp_rtx_queue_unlink_and_free include/net/tcp.h:1762 [inline] tcp_clean_rtx_queue net/ipv4/tcp_input.c:3141 [inline] tcp_ack+0x1eb0/0x58a0 net/ipv4/tcp_input.c:3668 tcp_rcv_established+0x19cb/0x2190 net/ipv4/tcp_input.c:5573 tcp_v4_do_rcv+0x635/0x8f0 net/ipv4/tcp_ipv4.c:1538 sk_backlog_rcv include/net/sock.h:932 [inline] __release_sock+0x12f/0x3a0 net/core/sock.c:2284 release_sock+0xad/0x2c0 net/core/sock.c:2797 tcp_sendmsg+0x3a/0x50 net/ipv4/tcp.c:1444 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 sock_write_iter+0x35e/0x5c0 net/socket.c:901 call_write_iter include/linux/fs.h:1863 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x72c/0xab0 fs/read_write.c:487 vfs_write+0x1fc/0x580 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881ba4b4dc0 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 624 bytes inside of 1024-byte region [ffff8881ba4b4dc0, ffff8881ba4b51c0) The buggy address belongs to the page: page:ffffea0006e92d00 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0xffff8881ba4b44c0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0006f29e08 ffffea0006f12208 ffff8881da800ac0 raw: ffff8881ba4b44c0 ffff8881ba4b4040 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ba4b4f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ba4b4f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881ba4b5000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ba4b5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ba4b5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================