Skip to content

Fix undefined behavior: incorrect usage of strlcpy #35

@VVD

Description

@VVD

Discussed in discord.

If the src and dst strings overlap, the behavior is undefined.

--- src/fs.c.orig       2025-02-16 14:10:58 UTC
+++ src/fs.c
@@ -119,6 +119,7 @@ void FS_StripPathAndExtension(char *filepath)
        size_t lastslash = (size_t) -1;
        size_t lastdot   = (size_t) -1;
        size_t i                 = 0;
+       char temp_filepath[MAX_QPATH];

        for ( ; filepath[i]; i++)
        {
@@ -131,7 +132,8 @@ void FS_StripPathAndExtension(char *filepath)
        if (lastdot == (size_t) -1 || lastdot < lastslash)
                lastdot = i;

-       strlcpy(filepath, filepath + lastslash + 1, lastdot - lastslash);
+       strlcpy(temp_filepath, filepath + lastslash + 1, lastdot - lastslash);
+       strlcpy(filepath, temp_filepath, sizeof(temp_filepath));
 }

 // return file extension with dot, or empty string if dot not found at all
--- src/net_utils.c.orig        2025-02-16 14:10:58 UTC
+++ src/net_utils.c
@@ -60,11 +60,13 @@ char *Net_BaseAdrToString (struct sockaddr_in *a, char
        // Windows have inet_ntop only starting from Vista. Sigh.
 #ifdef _WIN32
        const char *result = inet_ntoa(a->sin_addr);
+       strlcpy(buf, result ? result : "", bufsize);
 #else
        const char *result = inet_ntop(a->sin_family, &a->sin_addr, buf, bufsize);
+       if (!result) {
+               strlcpy(buf, "", bufsize);
+       }
 #endif
-
-       strlcpy(buf, result ? result : "", bufsize);

        return buf;
 }

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions