sudo/SOURCES/sudo-1.9.12-CVE-2023-22809-...

172 lines
5.1 KiB
Diff

diff -up ./plugins/sudoers/editor.c.other ./plugins/sudoers/editor.c
--- ./plugins/sudoers/editor.c.other 2023-01-16 17:37:04.659967300 +0100
+++ ./plugins/sudoers/editor.c 2023-01-16 17:40:35.944400376 +0100
@@ -39,6 +39,82 @@
#include "sudoers.h"
/*
+ * Non-destructive word-split that handles single and double quotes and
+ * escaped white space. Quotes are only recognized at the start of a word.
+ * They are treated as normal characters inside a word.
+ */
+static const char *
+wordsplit(const char *str, const char *endstr, const char **last)
+{
+ const char *cp;
+ debug_decl(wordsplit, SUDO_DEBUG_UTIL);
+
+ /* If no str specified, use last ptr (if any). */
+ if (str == NULL) {
+ str = *last;
+ /* Consume end quote if present. */
+ if (*str == '"' || *str == '\'')
+ str++;
+ }
+
+ /* Skip leading white space characters. */
+ while (str < endstr && (*str == ' ' || *str == '\t'))
+ str++;
+
+ /* Empty string? */
+ if (str >= endstr) {
+ *last = endstr;
+ debug_return_ptr(NULL);
+ }
+
+ /* If word is quoted, skip to end quote and return. */
+ if (*str == '"' || *str == '\'') {
+ const char *endquote = memchr(str + 1, *str, endstr - str);
+ if (endquote != NULL) {
+ *last = endquote;
+ debug_return_const_ptr(str + 1);
+ }
+ }
+
+ /* Scan str until we encounter white space. */
+ for (cp = str; cp < endstr; cp++) {
+ if (*cp == '\\') {
+ /* quoted char, do not interpret */
+ cp++;
+ continue;
+ }
+ if (*cp == ' ' || *cp == '\t') {
+ /* end of word */
+ break;
+ }
+ }
+ *last = cp;
+ debug_return_const_ptr(str);
+}
+
+/* Copy len chars from string, collapsing chars escaped with a backslash. */
+static char *
+copy_arg(const char *src, size_t len)
+{
+ const char *src_end = src + len;
+ char *copy, *dst;
+ debug_decl(copy_arg, SUDOERS_DEBUG_UTIL);
+
+ if ((copy = malloc(len + 1)) != NULL) {
+ for (dst = copy; src < src_end; ) {
+ if (*src == '\\') {
+ src++;
+ continue;
+ }
+ *dst++ = *src++;
+ }
+ *dst = '\0';
+ }
+
+ debug_return_ptr(copy);
+}
+
+/*
* Search for the specified editor in the user's PATH, checking
* the result against allowlist if non-NULL. An argument vector
* suitable for execve() is allocated and stored in argv_out.
@@ -52,7 +128,7 @@ static char *
resolve_editor(const char *ed, size_t edlen, int nfiles, char **files,
int *argc_out, char ***argv_out, char * const *allowlist)
{
- char **nargv, *editor, *editor_path = NULL;
+ char **nargv = NULL, *editor = NULL, *editor_path = NULL;
const char *cp, *ep, *tmp;
const char *edend = ed + edlen;
struct stat user_editor_sb;
@@ -64,14 +140,12 @@ resolve_editor(const char *ed, size_t ed
* The EDITOR and VISUAL environment variables may contain command
* line args so look for those and alloc space for them too.
*/
- cp = sudo_strsplit(ed, edend, " \t", &ep);
+ cp = wordsplit(ed, edend, &ep);
if (cp == NULL)
debug_return_str(NULL);
- editor = strndup(cp, (size_t)(ep - cp));
- if (editor == NULL) {
- sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
- debug_return_str(NULL);
- }
+ editor = copy_arg(cp, ep - cp);
+ if (editor == NULL)
+ goto oom;
/* If we can't find the editor in the user's PATH, give up. */
if (find_path(editor, &editor_path, &user_editor_sb, getenv("PATH"), 0, allowlist) != FOUND) {
@@ -81,30 +155,22 @@ resolve_editor(const char *ed, size_t ed
}
/* Count rest of arguments and allocate editor argv. */
- for (nargc = 1, tmp = ep; sudo_strsplit(NULL, edend, " \t", &tmp) != NULL; )
+ for (nargc = 1, tmp = ep; wordsplit(NULL, edend, &tmp) != NULL; )
nargc++;
if (nfiles != 0)
nargc += nfiles + 1;
nargv = reallocarray(NULL, nargc + 1, sizeof(char *));
- if (nargv == NULL) {
- sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
- free(editor);
- free(editor_path);
- debug_return_str(NULL);
- }
+ if (nargv == NULL)
+ goto oom;
/* Fill in editor argv (assumes files[] is NULL-terminated). */
nargv[0] = editor;
- for (nargc = 1; (cp = sudo_strsplit(NULL, edend, " \t", &ep)) != NULL; nargc++) {
- nargv[nargc] = strndup(cp, (size_t)(ep - cp));
- if (nargv[nargc] == NULL) {
- sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
- free(editor_path);
- while (nargc--)
- free(nargv[nargc]);
- free(nargv);
- debug_return_str(NULL);
- }
+ editor = NULL;
+ for (nargc = 1; (cp = wordsplit(NULL, edend, &ep)) != NULL; nargc++) {
+ /* Copy string, collapsing chars escaped with a backslash. */
+ nargv[nargc] = copy_arg(cp, ep - cp);
+ if (nargv[nargc] == NULL)
+ goto oom;
}
if (nfiles != 0) {
nargv[nargc++] = "--";
@@ -116,6 +182,16 @@ resolve_editor(const char *ed, size_t ed
*argc_out = nargc;
*argv_out = nargv;
debug_return_str(editor_path);
+oom:
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ free(editor);
+ free(editor_path);
+ if (nargv != NULL) {
+ while (nargc--)
+ free(nargv[nargc]);
+ free(nargv);
+ }
+ debug_return_str(NULL);
}
/*