================================================================== BUG: KASAN: double-free or invalid-free in skb_free_head+0x74/0xb0 net/core/skbuff.c:550 CPU: 1 PID: 3144 Comm: sshd Not tainted 4.15.0-rc4-next-20171221+ #78 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_double_free+0x55/0x80 mm/kasan/report.c:333 kasan_slab_free+0xa3/0xc0 mm/kasan/kasan.c:514 __cache_free mm/slab.c:3489 [inline] kfree+0xd6/0x260 mm/slab.c:3804 skb_free_head+0x74/0xb0 net/core/skbuff.c:550 skb_release_data+0x58c/0x790 net/core/skbuff.c:570 skb_release_all+0x4a/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] consume_skb+0x153/0x490 net/core/skbuff.c:701 __dev_kfree_skb_any+0x85/0xa0 net/core/dev.c:2532 dev_consume_skb_any include/linux/netdevice.h:3278 [inline] free_old_xmit_skbs.isra.27+0x15a/0x2c0 drivers/net/virtio_net.c:1170 start_xmit+0x1b9/0x1650 drivers/net/virtio_net.c:1317 __netdev_start_xmit include/linux/netdevice.h:4045 [inline] netdev_start_xmit include/linux/netdevice.h:4054 [inline] xmit_one net/core/dev.c:3008 [inline] dev_hard_start_xmit+0x248/0xac0 net/core/dev.c:3024 sch_direct_xmit+0x2e0/0x920 net/sched/sch_generic.c:300 qdisc_restart net/sched/sch_generic.c:366 [inline] __qdisc_run+0x571/0x1930 net/sched/sch_generic.c:374 __dev_xmit_skb net/core/dev.c:3189 [inline] __dev_queue_xmit+0x89e/0x2200 net/core/dev.c:3489 dev_queue_xmit+0x17/0x20 net/core/dev.c:3554 neigh_hh_output include/net/neighbour.h:472 [inline] neigh_output include/net/neighbour.h:480 [inline] ip_finish_output2+0xec8/0x1460 net/ipv4/ip_output.c:229 ip_finish_output+0x85e/0xd10 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:270 [inline] ip_output+0x1cc/0x860 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:443 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 ip_queue_xmit+0x8c0/0x18e0 net/ipv4/ip_output.c:504 tcp_transmit_skb+0x1b12/0x38b0 net/ipv4/tcp_output.c:1176 tcp_write_xmit+0x680/0x5190 net/ipv4/tcp_output.c:2367 __tcp_push_pending_frames+0xa0/0x250 net/ipv4/tcp_output.c:2540 tcp_push+0x538/0x770 net/ipv4/tcp.c:728 tcp_sendmsg_locked+0x2663/0x3b30 net/ipv4/tcp.c:1422 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1459 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:628 [inline] sock_sendmsg+0xca/0x110 net/socket.c:638 sock_write_iter+0x31a/0x5d0 net/socket.c:907 call_write_iter include/linux/fs.h:1776 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x7f16b0aea370 RSP: 002b:00007ffcf75c9cb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ffcf75c9dc0 RCX: 00007f16b0aea370 RDX: 0000000000000038 RSI: 000055c0663f8460 RDI: 0000000000000003 RBP: 000055c064f668dc R08: 0000000000000001 R09: 0101010101010101 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffcf75c9dc8 R13: 0000000000000000 R14: 00007ffcf75c9db8 R15: 00007ffcf75c9dbc Allocated by task 3144: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 __do_kmalloc_node mm/slab.c:3673 [inline] __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3687 __kmalloc_reserve.isra.41+0x41/0xd0 net/core/skbuff.c:137 __alloc_skb+0x13b/0x780 net/core/skbuff.c:205 alloc_skb_fclone include/linux/skbuff.h:1025 [inline] sk_stream_alloc_skb+0x11d/0x900 net/ipv4/tcp.c:868 tcp_sendmsg_locked+0x1341/0x3b30 net/ipv4/tcp.c:1297 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1459 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:628 [inline] sock_sendmsg+0xca/0x110 net/socket.c:638 sock_write_iter+0x31a/0x5d0 net/socket.c:907 call_write_iter include/linux/fs.h:1776 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x1f/0x96 Freed by task 3144: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3489 [inline] kfree+0xd6/0x260 mm/slab.c:3804 skb_free_head+0x74/0xb0 net/core/skbuff.c:550 skb_release_data+0x58c/0x790 net/core/skbuff.c:570 skb_release_all+0x4a/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] consume_skb+0x153/0x490 net/core/skbuff.c:701 __dev_kfree_skb_any+0x85/0xa0 net/core/dev.c:2532 dev_consume_skb_any include/linux/netdevice.h:3278 [inline] free_old_xmit_skbs.isra.27+0x15a/0x2c0 drivers/net/virtio_net.c:1170 start_xmit+0x1b9/0x1650 drivers/net/virtio_net.c:1317 __netdev_start_xmit include/linux/netdevice.h:4045 [inline] netdev_start_xmit include/linux/netdevice.h:4054 [inline] xmit_one net/core/dev.c:3008 [inline] dev_hard_start_xmit+0x248/0xac0 net/core/dev.c:3024 sch_direct_xmit+0x2e0/0x920 net/sched/sch_generic.c:300 qdisc_restart net/sched/sch_generic.c:366 [inline] __qdisc_run+0x571/0x1930 net/sched/sch_generic.c:374 __dev_xmit_skb net/core/dev.c:3189 [inline] __dev_queue_xmit+0x89e/0x2200 net/core/dev.c:3489 dev_queue_xmit+0x17/0x20 net/core/dev.c:3554 neigh_hh_output include/net/neighbour.h:472 [inline] neigh_output include/net/neighbour.h:480 [inline] ip_finish_output2+0xec8/0x1460 net/ipv4/ip_output.c:229 ip_finish_output+0x85e/0xd10 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:270 [inline] ip_output+0x1cc/0x860 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:443 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 ip_queue_xmit+0x8c0/0x18e0 net/ipv4/ip_output.c:504 tcp_transmit_skb+0x1b12/0x38b0 net/ipv4/tcp_output.c:1176 tcp_write_xmit+0x680/0x5190 net/ipv4/tcp_output.c:2367 __tcp_push_pending_frames+0xa0/0x250 net/ipv4/tcp_output.c:2540 tcp_push+0x538/0x770 net/ipv4/tcp.c:728 tcp_sendmsg_locked+0x2663/0x3b30 net/ipv4/tcp.c:1422 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1459 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:628 [inline] sock_sendmsg+0xca/0x110 net/socket.c:638 sock_write_iter+0x31a/0x5d0 net/socket.c:907 call_write_iter include/linux/fs.h:1776 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x1f/0x96 The buggy address belongs to the object at ffff8801c5867200 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 0 bytes inside of 1024-byte region [ffff8801c5867200, ffff8801c5867600) The buggy address belongs to the page: page:00000000f14a38b8 count:1 mapcount:0 mapping:0000000033f193a4 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801c5866000 0000000000000000 0000000100000007 raw: ffffea0007161820 ffffea0007165720 ffff8801dac00ac0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c5867100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c5867180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c5867200: fb fb fb fb 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff8801c5867280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c5867300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================