Hello, syzbot found the following issue on:
HEAD commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12b12c13500000 kernel config: https://syzkaller.appspot.com/x/.config?x=267a60b188ded8ed dashboard link: https://syzkaller.appspot.com/bug?extid=8f90d005ab2d22342b6d compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b) Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+8f90d005ab2d22342...@syzkaller.appspotmail.com ================================================================================ UBSAN: object-size-mismatch in ./include/linux/skbuff.h:2021:28 member access within address 0000000085889cc2 with insufficient space for an object of type 'struct sk_buff' CPU: 1 PID: 2998 Comm: kworker/1:2 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x137/0x1be lib/dump_stack.c:120 ubsan_epilogue lib/ubsan.c:148 [inline] handle_object_size_mismatch lib/ubsan.c:297 [inline] ubsan_type_mismatch_common+0x1e2/0x390 lib/ubsan.c:310 __ubsan_handle_type_mismatch_v1+0x41/0x50 lib/ubsan.c:339 __skb_queue_before include/linux/skbuff.h:2021 [inline] __skb_queue_tail include/linux/skbuff.h:2054 [inline] wg_xmit+0x45d/0xdf0 drivers/net/wireguard/device.c:182 __netdev_start_xmit include/linux/netdevice.h:4775 [inline] netdev_start_xmit+0x7b/0x140 include/linux/netdevice.h:4789 xmit_one net/core/dev.c:3556 [inline] dev_hard_start_xmit+0x182/0x2e0 net/core/dev.c:3572 __dev_queue_xmit+0x1229/0x1e60 net/core/dev.c:4133 neigh_output include/net/neighbour.h:510 [inline] ip6_finish_output2+0xe8d/0x11e0 net/ipv6/ip6_output.c:117 dst_output include/net/dst.h:441 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] ndisc_send_skb+0x85b/0xc70 net/ipv6/ndisc.c:508 addrconf_dad_completed+0x5ef/0x990 net/ipv6/addrconf.c:4192 addrconf_dad_work+0xb92/0x1480 net/ipv6/addrconf.c:3959 process_one_work+0x471/0x830 kernel/workqueue.c:2275 worker_thread+0x757/0xb10 kernel/workqueue.c:2421 kthread+0x39a/0x3c0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 ================================================================================ --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkal...@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.