From: Lucas De Marchi <lucas.de.marchi@gmail.com>
Date: Sat, 30 Nov 2024 16:53:49 +0000 (-0600)
Subject: libkmod/zstd: Do not re-use size_t for ret
X-Git-Tag: v34~34
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9fd66bee036301e47c354798d0816cf72534ccc3;p=thirdparty%2Fkmod.git

libkmod/zstd: Do not re-use size_t for ret

size_t is unsigned, while the function returns a negative number.
Instead of using `ret` for the return from ZSTD_decompress(), re-use
dst_size that should be the same as we passed in for that call since
it already checks for ZSTD_CONTENTSIZE_UNKNOWN and ZSTD_CONTENTSIZE_ERROR.

Even if it's not the same, it's more correct to use that value to
assign to file->size to avoid accessing uninitialized memory.

Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/262
---

diff --git a/libkmod/libkmod-file-zstd.c b/libkmod/libkmod-file-zstd.c
index 97150006..220d77ab 100644
--- a/libkmod/libkmod-file-zstd.c
+++ b/libkmod/libkmod-file-zstd.c
@@ -22,9 +22,10 @@
 int kmod_file_load_zstd(struct kmod_file *file)
 {
 	void *src_buf = MAP_FAILED, *dst_buf = NULL;
-	size_t src_size, dst_size, ret;
+	size_t src_size, dst_size;
 	unsigned long long frame_size;
 	struct stat st;
+	int ret;
 
 	if (fstat(file->fd, &st) < 0) {
 		ret = -errno;
@@ -64,9 +65,9 @@ int kmod_file_load_zstd(struct kmod_file *file)
 		goto out;
 	}
 
-	ret = ZSTD_decompress(dst_buf, dst_size, src_buf, src_size);
-	if (ZSTD_isError(ret)) {
-		ERR(file->ctx, "zstd: %s\n", ZSTD_getErrorName(ret));
+	dst_size = ZSTD_decompress(dst_buf, dst_size, src_buf, src_size);
+	if (ZSTD_isError(dst_size)) {
+		ERR(file->ctx, "zstd: %s\n", ZSTD_getErrorName(dst_size));
 		ret = -EINVAL;
 		goto out;
 	}