From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Wed, 18 Dec 2024 09:37:14 +0000 (+0100)
Subject: strbuf: Extend strbuf_reserve_extra size check
X-Git-Tag: v34~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=235a38bf51ee21e73de0110d7d22894f308920b9;p=thirdparty%2Fkmod.git

strbuf: Extend strbuf_reserve_extra size check

Make sure that alignment to BUF_STEP won't overflow if excessively
huge amount of memory is requested to be reserved.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Link: https://github.com/kmod-project/kmod/pull/268
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
---

diff --git a/shared/strbuf.c b/shared/strbuf.c
index 0dd7a5b0..332dbd33 100644
--- a/shared/strbuf.c
+++ b/shared/strbuf.c
@@ -36,7 +36,7 @@ static bool buf_realloc(struct strbuf *buf, size_t sz)
 
 bool strbuf_reserve_extra(struct strbuf *buf, size_t n)
 {
-	if (uaddsz_overflow(buf->used, n, &n))
+	if (uaddsz_overflow(buf->used, n, &n) || n > SIZE_MAX - BUF_STEP)
 		return false;
 
 	if (n <= buf->size)