From 7e5b6a5c8c44310784c88c1c198dde79f6402f7b Mon Sep 17 00:00:00 2001 From: Tom Rix Date: Mon, 14 Feb 2022 18:05:41 -0800 Subject: [PATCH] mctp: fix use after free Clang static analysis reports this problem route.c:425:4: warning: Use of memory after it is freed trace_mctp_key_acquire(key); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ When mctp_key_add() fails, key is freed but then is later used in trace_mctp_key_acquire(). Add an else statement to use the key only when mctp_key_add() is successful. Fixes: 4f9e1ba6de45 ("mctp: Add tracepoints for tag/key handling") Signed-off-by: Tom Rix Signed-off-by: David S. Miller --- net/mctp/route.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/mctp/route.c b/net/mctp/route.c index 8d9f4ff3e285..e52cef750500 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -412,13 +412,14 @@ static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb) * this function. */ rc = mctp_key_add(key, msk); - if (rc) + if (rc) { kfree(key); + } else { + trace_mctp_key_acquire(key); - trace_mctp_key_acquire(key); - - /* we don't need to release key->lock on exit */ - mctp_key_unref(key); + /* we don't need to release key->lock on exit */ + mctp_key_unref(key); + } key = NULL; } else {