From 56fb102c0c6094792fd38455b38b88a94454e996 Mon Sep 17 00:00:00 2001 From: Christopher Faulet Date: Wed, 28 Aug 2024 15:42:22 +0200 Subject: [PATCH] BUG/MEDIUM: stream: Prevent mux upgrades if client connection is no longer ready If an early error occurred on the client connection, we must prevent any multiplexer upgrades. Indeed, it is unexpected for a mux to be initialized with no xprt. On a normal workflow it is impossible. So it is not an issue. But if a mux upgrade is performed at the stream level, an early error on the connection may have already been handled by the previous mux and the connection may be already fully closed. If the mux upgrade is still performed, a crash can be experienced. It is possible to have a crash with an implicit TCP>HTTP upgrade if there is no data in the input buffer. But it is also possible to get a crash with an explicit "switch-mode http" rule. It must be backported to all stable versions. In 2.2, the patch must be applied directly in stream_set_backend() function. (cherry picked from commit e4812404c541018ba521abf6573be92553ba7c53) Signed-off-by: Willy Tarreau (cherry picked from commit 13437097c312e524a346b9016d8ab273374d2053) Signed-off-by: Christopher Faulet Conflict: NA Reference: https://github.com/haproxy/haproxy/commit/56fb102c0c6094792fd38455b38b88a94454e996 --- src/stream.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/stream.c b/src/stream.c index e643a6db6a05..89b7c238fe48 100644 --- a/src/stream.c +++ b/src/stream.c @@ -1488,6 +1488,10 @@ int stream_set_http_mode(struct stream *s, const struct mux_proto_list *mux_prot return 0; conn = sc_conn(sc); + + if (!sc_conn_ready(sc)) + return 0; + if (conn) { se_have_more_data(s->scf->sedesc); /* Make sure we're unsubscribed, the the new