On Tue, Jun 18, 2024 at 02:24:45PM +0200, Matthieu Baerts (NGI0) wrote: > From: Paolo Abeni <pabeni@xxxxxxxxxx> > > commit 8031b58c3a9b1db3ef68b3bd749fbee2e1e1aaa3 upstream. > > This is strictly related to commit fb7a0d334894 ("mptcp: ensure snd_nxt > is properly initialized on connect"). It turns out that syzkaller can > trigger the retransmit after fallback and before processing any other > incoming packet - so that snd_una is still left uninitialized. > > Address the issue explicitly initializing snd_una together with snd_nxt > and write_seq. > > Suggested-by: Mat Martineau <martineau@xxxxxxxxxx> > Fixes: 8fd738049ac3 ("mptcp: fallback in case of simultaneous connect") > Cc: stable@xxxxxxxxxxxxxxx > Reported-by: Christoph Paasch <cpaasch@xxxxxxxxx> > Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/485 > Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> > Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx> > Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> > Link: https://lore.kernel.org/r/20240607-upstream-net-20240607-misc-fixes-v1-1-1ab9ddfa3d00@xxxxxxxxxx > Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> > [ Conflicts in protocol.c, similar to the ones from commit 99951b62bf20 > ("mptcp: ensure snd_nxt is properly initialized on connect"), with the > same resolution. Note that in this version, 'snd_una' is an atomic64 > type, so use atomic64_set() instead, as it is done everywhere else. ] > Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> > --- > net/mptcp/protocol.c | 1 + > 1 file changed, 1 insertion(+) All backports now queued up, thanks. greg k-h