================================================================== BUG: KASAN: use-after-free in eth_header_parse_protocol+0xad/0xd0 net/ethernet/eth.c:282 Read of size 2 at addr ffff8881ecfc000b by task syz-executor.4/15086 CPU: 1 PID: 15086 Comm: syz-executor.4 Not tainted 5.4.106-syzkaller-00698-g3941336d0e38 #0 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+0x1d8/0x24e lib/dump_stack.c:118 print_address_description+0x9b/0x650 mm/kasan/report.c:384 __kasan_report+0x182/0x260 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:641 eth_header_parse_protocol+0xad/0xd0 net/ethernet/eth.c:282 dev_parse_header_protocol include/linux/netdevice.h:2984 [inline] virtio_net_hdr_to_skb+0x6de/0xd70 include/linux/virtio_net.h:83 packet_snd net/packet/af_packet.c:2976 [inline] packet_sendmsg+0x483a/0x6780 net/packet/af_packet.c:3013 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg net/socket.c:658 [inline] sock_write_iter+0x330/0x450 net/socket.c:990 call_write_iter include/linux/fs.h:1971 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0x5ec/0x780 fs/read_write.c:496 vfs_write+0x212/0x4e0 fs/read_write.c:558 ksys_write+0x186/0x2b0 fs/read_write.c:611 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x465f69 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f03a6627188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000465f69 RDX: 000000000000fdef RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00000000004bfa8f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffd614453df R14: 00007f03a6627300 R15: 0000000000022000 Allocated by task 15021: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x137/0x1e0 mm/kasan/common.c:517 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2829 [inline] __kmalloc_track_caller+0x13a/0x2e0 mm/slub.c:4439 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0xaf/0x4d0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1057 [inline] nlmsg_new include/net/netlink.h:888 [inline] rtmsg_ifinfo_build_skb+0x81/0x180 net/core/rtnetlink.c:3500 rtmsg_ifinfo_event net/core/rtnetlink.c:3536 [inline] rtmsg_ifinfo+0x73/0x120 net/core/rtnetlink.c:3545 __dev_notify_flags+0xe0/0x4f0 net/core/dev.c:7921 rtnl_configure_link+0x216/0x320 net/core/rtnetlink.c:2914 veth_newlink+0x6d2/0xaf0 drivers/net/veth.c:1310 __rtnl_newlink net/core/rtnetlink.c:3227 [inline] rtnl_newlink+0x1558/0x1ce0 net/core/rtnetlink.c:3286 rtnetlink_rcv_msg+0xb74/0xd00 net/core/rtnetlink.c:5255 netlink_rcv_skb+0x200/0x480 net/netlink/af_netlink.c:2478 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x865/0x9f0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x9ab/0xd40 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg net/socket.c:658 [inline] __sys_sendto+0x4f1/0x6c0 net/socket.c:1953 __do_sys_sendto net/socket.c:1965 [inline] __se_sys_sendto net/socket.c:1961 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:1961 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 15021: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:333 [inline] __kasan_slab_free+0x18a/0x240 mm/kasan/common.c:475 slab_free_hook mm/slub.c:1454 [inline] slab_free_freelist_hook+0x7b/0x150 mm/slub.c:1492 slab_free mm/slub.c:3072 [inline] kfree+0xe0/0x660 mm/slub.c:4061 skb_free_head net/core/skbuff.c:601 [inline] pskb_expand_head+0x350/0xfa0 net/core/skbuff.c:1672 netlink_trim+0x194/0x230 net/netlink/af_netlink.c:1285 netlink_broadcast_filtered+0x6d/0x10a0 net/netlink/af_netlink.c:1490 netlink_broadcast net/netlink/af_netlink.c:1535 [inline] nlmsg_multicast include/net/netlink.h:968 [inline] nlmsg_notify+0xa2/0x140 net/netlink/af_netlink.c:2521 __dev_notify_flags+0xe0/0x4f0 net/core/dev.c:7921 rtnl_configure_link+0x216/0x320 net/core/rtnetlink.c:2914 veth_newlink+0x6d2/0xaf0 drivers/net/veth.c:1310 __rtnl_newlink net/core/rtnetlink.c:3227 [inline] rtnl_newlink+0x1558/0x1ce0 net/core/rtnetlink.c:3286 rtnetlink_rcv_msg+0xb74/0xd00 net/core/rtnetlink.c:5255 netlink_rcv_skb+0x200/0x480 net/netlink/af_netlink.c:2478 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x865/0x9f0 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x9ab/0xd40 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg net/socket.c:658 [inline] __sys_sendto+0x4f1/0x6c0 net/socket.c:1953 __do_sys_sendto net/socket.c:1965 [inline] __se_sys_sendto net/socket.c:1961 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:1961 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8881ecfc0000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 11 bytes inside of 4096-byte region [ffff8881ecfc0000, ffff8881ecfc1000) The buggy address belongs to the page: page:ffffea0007b3f000 refcount:1 mapcount:0 mapping:ffff8881f5c0c280 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c0c280 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ecfbff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881ecfbff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881ecfc0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ecfc0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ecfc0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================