================================================================== BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline] BUG: KASAN: use-after-free in skb_copy_from_linear_data_offset include/linux/skbuff.h:3676 [inline] BUG: KASAN: use-after-free in skb_segment+0x14ba/0x37a0 net/core/skbuff.c:4000 Read of size 5649 at addr ffff8880279c6c5e by task syz-executor.2/18549 CPU: 0 PID: 18549 Comm: syz-executor.2 Not tainted 5.11.0-rc4-next-20210120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230 __kasan_report mm/kasan/report.c:397 [inline] kasan_report.cold+0x79/0xd5 mm/kasan/report.c:414 check_region_inline mm/kasan/generic.c:180 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186 memcpy+0x20/0x60 mm/kasan/shadow.c:65 memcpy include/linux/fortify-string.h:191 [inline] skb_copy_from_linear_data_offset include/linux/skbuff.h:3676 [inline] skb_segment+0x14ba/0x37a0 net/core/skbuff.c:4000 udp4_ufo_fragment+0x4ae/0x700 net/ipv4/udp_offload.c:363 inet_gso_segment+0x502/0x1110 net/ipv4/af_inet.c:1378 skb_mac_gso_segment+0x26e/0x530 net/core/dev.c:3326 __skb_gso_segment+0x330/0x6e0 net/core/dev.c:3399 skb_gso_segment include/linux/netdevice.h:4712 [inline] validate_xmit_skb+0x69e/0xee0 net/core/dev.c:3644 __dev_queue_xmit+0x988/0x2dd0 net/core/dev.c:4142 br_dev_queue_push_xmit+0x252/0x740 net/bridge/br_forward.c:51 NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] br_forward_finish net/bridge/br_forward.c:64 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] __br_forward+0x46d/0x610 net/bridge/br_forward.c:108 br_flood+0x3b2/0x450 net/bridge/br_forward.c:233 br_dev_xmit+0x1014/0x1690 net/bridge/br_device.c:99 __netdev_start_xmit include/linux/netdevice.h:4762 [inline] netdev_start_xmit include/linux/netdevice.h:4776 [inline] xmit_one net/core/dev.c:3574 [inline] dev_hard_start_xmit+0x1eb/0x920 net/core/dev.c:3590 __dev_queue_xmit+0x21db/0x2dd0 net/core/dev.c:4151 packet_snd net/packet/af_packet.c:3006 [inline] packet_sendmsg+0x2406/0x52a0 net/packet/af_packet.c:3031 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:672 __sys_sendto+0x21c/0x320 net/socket.c:1975 __do_sys_sendto net/socket.c:1987 [inline] __se_sys_sendto net/socket.c:1983 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:1983 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e219 Code: 0d b4 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fdafed44c68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 000000000045e219 RDX: 000000000000fc13 RSI: 0000000020000280 RDI: 0000000000000005 RBP: 000000000119bfd8 R08: 0000000000000000 R09: 000000000000002f R10: 0000000000000800 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007fffa70bb5ef R14: 00007fdafed459c0 R15: 000000000119bf8c The buggy address belongs to the page: page:000000002e816fb0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x279c4 head:000000002e816fb0 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010000(head) raw: 00fff00000010000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880279c7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880279c7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880279c8000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880279c8080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880279c8100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================