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+d1b1723faccb7a43f...@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? Thanks! Paolo
