6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Matthieu Baerts (NGI0) matttbe@kernel.org
commit ee79980f7a428ec299f6261bea4c1084dcbc9631 upstream.
MPTCP Join "fastclose server" selftest is sometimes failing because the client output file doesn't have the expected size, e.g. 296B instead of 1024B.
When looking at a packet trace when this happens, the server sent the expected 1024B in two parts -- 100B, then 924B -- then the MP_FASTCLOSE. It is then strange to see the client only receiving 296B, which would mean it only got a part of the second packet. The problem is then not on the networking side, but rather on the data reception side.
When mptcp_connect is launched with '-f -1', it means the connection might stop before having sent everything, because a reset has been received. When this happens, the program was directly stopped. But it is also possible there are still some data to read, simply because the previous 'read' step was done with a buffer smaller than the pending data, see do_rnd_read(). In this case, it is important to read what's left in the kernel buffers before stopping without error like before.
SIGPIPE is now ignored, not to quit the app before having read everything.
Fixes: 6bf41020b72b ("selftests: mptcp: update and extend fastclose test-cases") Cc: stable@vger.kernel.org Reviewed-by: Geliang Tang geliang@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Link: https://patch.msgid.link/20251110-net-mptcp-sft-join-unstable-v1-5-a4332c714... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/testing/selftests/net/mptcp/mptcp_connect.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.c +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c @@ -696,8 +696,14 @@ static int copyfd_io_poll(int infd, int
bw = do_rnd_write(peerfd, winfo->buf + winfo->off, winfo->len); if (bw < 0) { - if (cfg_rcv_trunc) - return 0; + /* expected reset, continue to read */ + if (cfg_rcv_trunc && + (errno == ECONNRESET || + errno == EPIPE)) { + fds.events &= ~POLLOUT; + continue; + } + perror("write"); return 111; } @@ -723,8 +729,10 @@ static int copyfd_io_poll(int infd, int }
if (fds.revents & (POLLERR | POLLNVAL)) { - if (cfg_rcv_trunc) - return 0; + if (cfg_rcv_trunc) { + fds.events &= ~(POLLERR | POLLNVAL); + continue; + } fprintf(stderr, "Unexpected revents: " "POLLERR/POLLNVAL(%x)\n", fds.revents); return 5; @@ -1419,7 +1427,7 @@ static void parse_opts(int argc, char ** */ if (cfg_truncate < 0) { cfg_rcv_trunc = true; - signal(SIGPIPE, handle_signal); + signal(SIGPIPE, SIG_IGN); } break; case 'j':