From: Emil Velikov <emil.l.velikov@gmail.com>
Date: Sat, 5 Apr 2025 10:39:42 +0000 (+0100)
Subject: Use sizeof() over PATH_MAX for bounds handling
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6c5e7997a13d3950414b8112a54c1ef8a4aaa22f;p=thirdparty%2Fkmod.git

Use sizeof() over PATH_MAX for bounds handling

Bunch of our codebase uses sizeof() while the rest hard-coded length for
the destination buffer. Converge on the former since it makes for more
obvious and less error prone code.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/345
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
---

diff --git a/libkmod/libkmod-builtin.c b/libkmod/libkmod-builtin.c
index b32848d9..2012239a 100644
--- a/libkmod/libkmod-builtin.c
+++ b/libkmod/libkmod-builtin.c
@@ -40,7 +40,7 @@ static bool kmod_builtin_info_init(struct kmod_builtin_info *info, struct kmod_c
 	const char *dirname = kmod_get_dirname(ctx);
 	size_t len = strlen(dirname);
 
-	if ((len + 1 + strlen(MODULES_BUILTIN_MODINFO) + 1) >= PATH_MAX) {
+	if ((len + 1 + strlen(MODULES_BUILTIN_MODINFO) + 1) >= sizeof(path)) {
 		errno = ENAMETOOLONG;
 		return false;
 	}
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index ff04ee19..fbfbd7b9 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -127,7 +127,7 @@ void kmod_module_parse_depline(struct kmod_module *mod, char *line)
 	*p = '\0';
 	dirname = kmod_get_dirname(mod->ctx);
 	dirnamelen = strlen(dirname);
-	if (dirnamelen + 2 >= PATH_MAX)
+	if (dirnamelen + 2 >= sizeof(buf))
 		return;
 
 	memcpy(buf, dirname, dirnamelen);
@@ -301,7 +301,7 @@ int kmod_module_new_from_alias(struct kmod_ctx *ctx, const char *alias, const ch
 	size_t namelen = strlen(name);
 	size_t aliaslen = strlen(alias);
 
-	if (namelen + aliaslen + 2 > PATH_MAX)
+	if (namelen + aliaslen + 2 > sizeof(key))
 		return -ENAMETOOLONG;
 
 	memcpy(key, name, namelen);
diff --git a/shared/tmpfile-util.c b/shared/tmpfile-util.c
index c9c20d23..1548d2d0 100644
--- a/shared/tmpfile-util.c
+++ b/shared/tmpfile-util.c
@@ -69,7 +69,7 @@ int tmpfile_publish(struct tmpfile *file, const char *targetname)
 
 	file->fd = -1;
 	file->dirfd = -1;
-	memset(file->tmpname, 0, PATH_MAX);
+	memset(file->tmpname, 0, sizeof(file->tmpname));
 
 	return 0;
 }