RE: [syzbot] [net?] WARNING in tcp_recvmsg_locked (2)

From: John Fastabend
Date: Tue Dec 05 2023 - 13:38:30 EST


syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 8470e4368b0f Merge branch 'net-cacheline-optimizations'
> git tree: net-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=12094286e80000
> kernel config: https://syzkaller.appspot.com/x/.config?x=f8715b6ede5c4b90
> dashboard link: https://syzkaller.appspot.com/bug?extid=06dbd397158ec0ea4983
> compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1247bee2e80000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1285243ce80000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/90007d08e178/disk-8470e436.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/b55270de1cdc/vmlinux-8470e436.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2237d34b6fec/bzImage-8470e436.xz
>
> The issue was bisected to:
>
> commit 965b57b469a589d64d81b1688b38dcb537011bb0
> Author: Cong Wang <cong.wang@xxxxxxxxxxxxx>
> Date: Wed Jun 15 16:20:12 2022 +0000
>
> net: Introduce a new proto_ops ->read_skb()
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1087c0d4e80000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=1287c0d4e80000
> console output: https://syzkaller.appspot.com/x/log.txt?x=1487c0d4e80000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+06dbd397158ec0ea4983@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 965b57b469a5 ("net: Introduce a new proto_ops ->read_skb()")
>
> WARNING: CPU: 1 PID: 5130 at net/ipv4/tcp.c:2396 tcp_recvmsg_locked+0xa54/0x2490 net/ipv4/tcp.c:2396

I'll take a look. Thanks.