[patch] fix sys-apps/sandbox-2.35 QA-notice

sandbox-2.35.patch (text/plain), 5.47 KB, created by gto7052 on 2023-07-10 17:35:28 UTC

# Fix QA Notices in sys-apps/sandbox-2.35 (and maybe also some recently reported sandbox errors)
# * QA Notice: Package triggers severe warnings which indicate that it
# *            may exhibit random runtime failures.
# * /tmp/portage/sys-apps/sandbox-2.35/work/sandbox-2.35/src/environ.c:211:19: warning: the comparison will always evaluate as ‘true’ for the address of ‘work_dir’ will never be NULL [-Waddress]
# * /tmp/portage/sys-apps/sandbox-2.35/work/sandbox-2.35/libsandbox/canonicalize.c:113:41: warning: passing argument 2 to 'restrict'-qualified parameter aliases with argument 1 [-Wrestrict]
# * /tmp/portage/sys-apps/sandbox-2.35/work/sandbox-2.35/libsandbox/libsandbox.c:144:9: warning: passing argument 2 to 'restrict'-qualified parameter aliases with argument 1 [-Wrestrict]
#
# * Please do not file a Gentoo bug and instead report the above QA
# * issues directly to the upstream developers of this software.
# * Homepage: https://wiki.gentoo.org/wiki/Project:Sandbox


diff --git a/libsandbox/canonicalize.c b/libsandbox/canonicalize.c
index f742ed4..68391c7 100644
--- a/libsandbox/canonicalize.c
+++ b/libsandbox/canonicalize.c
@@ -110,10 +110,17 @@ erealpath(const char *name, char *resolved)
 				if (lstat64(rpath, &st))
 					break;
 				if (S_ISLNK(st.st_mode)) {
-					ssize_t cnt = readlink(rpath, rpath, path_max);
+					/*   avoid undefined behaviour resulting from passing rpath
+					 *   as source and destination buffer to readlink:
+					 *   warning: passing argument 2 to 'restrict'-qualified
+					 *   parameter aliases with argument 1 [-Wrestrict]
+					 */
+				        char buffer[path_max];
+					ssize_t cnt = readlink(rpath, buffer, sizeof(buffer));
 					if (cnt == -1)
 						break;
-					rpath[cnt] = '\0';
+					buffer[cnt] = '\0';
+					strcpy(rpath,buffer);
 					if (p) {
 						size_t bytes_left = strlen(p);
 						if (bytes_left >= path_max)
diff --git a/libsandbox/libsandbox.c b/libsandbox/libsandbox.c
index 847b4e2..55347b9 100644
--- a/libsandbox/libsandbox.c
+++ b/libsandbox/libsandbox.c
@@ -131,7 +131,7 @@ int resolve_dirfd_path(int dirfd, const char *path, char *resolved_path,
 
 	save_errno();
 
-	size_t at_len = resolved_path_len - 1 - 1 - (path ? strlen(path) : 0);
+	/*unused: size_t at_len = resolved_path_len - 1 - 1 - (path ? strlen(path) : 0);*/
 	if (trace_pid) {
 		sprintf(resolved_path, "/proc/%i/fd/%i", trace_pid, dirfd);
 	} else {
@@ -141,7 +141,16 @@ int resolve_dirfd_path(int dirfd, const char *path, char *resolved_path,
 		 */
 		sprintf(resolved_path, "%s/%i", sb_get_fd_dir(), dirfd);
 	}
-	ssize_t ret = readlink(resolved_path, resolved_path, at_len);
+
+
+	/*   avoid undefined behaviour resulting from passing resolved_path 
+	 *   as source and destination buffer to readlink:
+	 *   C99 warning: passing argument 2 to 'restrict'-qualified 
+	 *   parameter aliases with argument 1 [-Wrestrict] 
+	 */
+	char buffer[resolved_path_len];
+
+	ssize_t ret = readlink(resolved_path, buffer, sizeof(buffer));
 	if (ret == -1) {
 		/* see comments at end of check_syscall() */
 		if (errno_is_too_long()) {
@@ -153,11 +162,25 @@ int resolve_dirfd_path(int dirfd, const char *path, char *resolved_path,
 		if (errno == ENOENT)
 			errno = EBADF;
 		return -1;
-	}
-	resolved_path[ret] = '/';
-	resolved_path[ret + 1] = '\0';
-	if (path)
-		strcat(resolved_path, path);
+	} else if (ret + 1 >= sizeof(buffer)) {
+		errno = ENOMEM;
+		sb_debug_dyn("AT_FD LOOKUP: unsufficient buffer space for resolved_path; max len is %ld; %s\n", sizeof(buffer), strerror(errno));
+		return -1;
+	} 
+
+	buffer[ret] = '/';
+	buffer[ret + 1] = '\0';
+	if (path) {
+	    if ( strlen(buffer) + strlen(path) + 1 < sizeof(buffer) ) {
+		 strcat(buffer, path);
+            } else {
+		  errno = ENOMEM;
+		  sb_debug_dyn("AT_FD LOOKUP: unsufficient buffer space for resolved_path+path; max len is %ld; %s\n", sizeof(buffer), strerror(errno));
+		  return -1;
+            }
+        }
+
+	strcpy(resolved_path,buffer);
 
 	restore_errno();
 	return 0;
diff --git a/src/environ.c b/src/environ.c
index 542dd64..2b28c0b 100644
--- a/src/environ.c
+++ b/src/environ.c
@@ -208,7 +208,7 @@ static int setup_cfg_vars(struct sandbox_info_t *sandbox_info)
 	if (-1 == setup_access_var(ENV_SANDBOX_WRITE))
 		return -1;
 	if ((NULL == getenv(ENV_SANDBOX_WRITE)) &&
-	    (NULL != sandbox_info->work_dir))
+	    strlen(sandbox_info->work_dir))
 		setenv(ENV_SANDBOX_WRITE, sandbox_info->work_dir, 1);
 
 	if (-1 == setup_access_var(ENV_SANDBOX_PREDICT))
diff --git a/src/sandbox.c b/src/sandbox.c
index ed0c7f6..7951d46 100644
--- a/src/sandbox.c
+++ b/src/sandbox.c
@@ -34,10 +34,12 @@ const char sbio_fallback_path[] = "/dev/stderr";
 
 static int setup_sandbox(struct sandbox_info_t *sandbox_info, bool interactive)
 {
-	if (NULL != getenv(ENV_PORTAGE_TMPDIR)) {
-		/* Portage handle setting SANDBOX_WRITE itself. */
-		sandbox_info->work_dir[0] = '\0';
-	} else {
+        /* avoid using uninitialized fields */
+	memset(sandbox_info,0,sizeof(*sandbox_info));
+
+
+	if (NULL == getenv(ENV_PORTAGE_TMPDIR)) {
+		/* Portage does not handle setting SANDBOX_WRITE itself. */
 		if (NULL == getcwd(sandbox_info->work_dir, SB_PATH_MAX)) {
 			sb_pwarn("failed to get current directory");
 			return -1;
@@ -249,7 +251,7 @@ int main(int argc, char **argv)
 	dputs("Setting up the required environment variables.");
 
 	/* If not in portage, cd into it work directory */
-	if ('\0' != sandbox_info.work_dir[0])
+	if (strlen(sandbox_info.work_dir))
 		if (chdir(sandbox_info.work_dir))
 			sb_perr("chdir(%s) failed", sandbox_info.work_dir);