Messages in this thread | | | From | Dmitry Vyukov <> | Date | Thu, 18 Feb 2021 15:04:02 +0100 | Subject | Re: possible deadlock in mptcp_push_pending |
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On Thu, Feb 18, 2021 at 1:41 PM Paolo Abeni <pabeni@redhat.com> wrote: > > On Wed, 2021-02-17 at 09:31 -0800, syzbot wrote: > > syzbot found the following issue on: > > > > HEAD commit: c48f8607 Merge branch 'PTP-for-DSA-tag_ocelot_8021q' > > git tree: net-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=16525cb0d00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=dbc1ca9e55dc1f9f > > dashboard link: https://syzkaller.appspot.com/bug?extid=d1b1723faccb7a43f6d1 > > > > 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+d1b1723faccb7a43f6d1@syzkaller.appspotmail.com > > > > ============================================ > > WARNING: possible recursive locking detected > > 5.11.0-rc7-syzkaller #0 Not tainted > > -------------------------------------------- > > syz-executor.1/15600 is trying to acquire lock: > > ffff888057303220 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1598 [inline] > > ffff888057303220 (sk_lock-AF_INET6){+.+.}-{0:0}, at: mptcp_push_pending+0x28b/0x650 net/mptcp/protocol.c:1466 > > Even this one is suspected to be a dup of 'WARNING in dst_release': the > subflow socket lock family is reported to be 'sk_lock-AF_INET6', but > subflows are created in kernel, and get 'k-sk_lock-AF_INET6'. This > looks like [re]use after free, likely via msk->first, as in the > suspected dup issue. Lacking a repro, I'm not 110% sure. > > @Dmitry, I'm wondering which is the preferred course of action here: > tentatively marking this one as a dup, or leaving it alone till we get > a reproducer?
Hi Paolo,
I don't have a strong opinion. Either way will work, especially since this seems to happen regularly. Or, submit a fix and wait to see if this stops happening or not.
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