On Tue, 2021-09-21 at 17:13 -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 1f77990c4b79 Add linux-next specific files for 20210920 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=1383891d300000 > kernel config: https://syzkaller.appspot.com/x/.config?x=ab1346371f2e6884 > dashboard link: https://syzkaller.appspot.com/bug?extid=3360da629681aa0d22fe > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1625f1ab300000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17eb1b3b300000 > > The issue was bisected to: > > commit 020250f31c4c75ac7687a673e29c00786582a5f4 > Author: Dmitry Kadashev <dkadashev@xxxxxxxxx> > Date: Thu Jul 8 06:34:43 2021 +0000 > > namei: make do_linkat() take struct filename > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15f5ef77300000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=17f5ef77300000 > console output: https://syzkaller.appspot.com/x/log.txt?x=13f5ef77300000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+3360da629681aa0d22fe@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 020250f31c4c ("namei: make do_linkat() take struct filename") I'm unsure why the bisection points to this commit. This looks like an MPTCP specific issue, due to bad handling of MSG_WAITALL recvmsg() flag. I'll test a fix with syzbot to confirm the above. Cheers, Paolo
