bpf build error

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    e6f6cd0d bpf: sockmap, fix use after free from sleep in ps..
git tree:       bpf
console output: https://syzkaller.appspot.com/x/log.txt?x=16f116e4a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fc045131472947d7
dashboard link: https://syzkaller.appspot.com/bug?extid=cbe357153903f8d9409a
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+cbe357153903f8d9409a@xxxxxxxxxxxxxxxxxxxxxxxxx

net/core/skbuff.c:2340:6: error: âstruct msghdrâ has no member named âflagsâ

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