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Use a common function for resolviong the user's editor in sudoedit

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and visudo.  The find_path() function now returns a dynamically
allocated path instead of using a static string.
This commit is contained in:
Todd C. Miller
2015-06-18 09:51:36 -06:00
parent a38253b101
commit ac13264b44
8 changed files with 366 additions and 308 deletions
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81
plugins/sudoers/find_path.c
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@@ -45,40 +45,82 @@
#include "sudoers.h"
/*
* Check the given command against the specified whitelist (NULL-terminated).
* On success, rewrites cmnd based on the whitelist and returns true.
* On failure, returns false.
*/
static bool
cmnd_allowed(char *cmnd, size_t cmnd_size, struct stat *cmnd_sbp,
char * const *whitelist)
{
const char *cmnd_base;
char * const *wl;
debug_decl(cmnd_allowed, SUDOERS_DEBUG_UTIL)
if (!sudo_goodpath(cmnd, cmnd_sbp))
debug_return_bool(false);
if (whitelist == NULL)
debug_return_bool(true); /* nothing to check */
/* We compare the base names to avoid excessive stat()ing. */
if ((cmnd_base = strrchr(cmnd, '/')) == NULL)
debug_return_bool(false); /* can't happen */
cmnd_base++;
for (wl = whitelist; *wl != NULL; wl++) {
struct stat sb;
const char *base;
if ((base = strrchr(*wl, '/')) == NULL)
continue; /* XXX - warn? */
base++;
if (strcmp(cmnd_base, base) != 0)
continue;
if (sudo_goodpath(*wl, &sb) &&
sb.st_dev == cmnd_sbp->st_dev && sb.st_ino == cmnd_sbp->st_ino) {
/* Overwrite cmnd with safe version from whitelist. */
if (strlcpy(cmnd, *wl, cmnd_size) < cmnd_size)
return true;
debug_return_bool(true);
}
}
debug_return_bool(false);
}
/*
* This function finds the full pathname for a command and
* stores it in a statically allocated array, filling in a pointer
* to the array. Returns FOUND if the command was found, NOT_FOUND
* if it was not found, or NOT_FOUND_DOT if it would have been found
* but it is in '.' and IGNORE_DOT is set.
* The caller is responsible for freeing the output file.
*/
int
find_path(const char *infile, char **outfile, struct stat *sbp,
const char *path, int ignore_dot)
const char *path, int ignore_dot, char * const *whitelist)
{
static char command[PATH_MAX];
char command[PATH_MAX];
const char *cp, *ep, *pathend;
bool found = false;
bool checkdot = false;
int len;
debug_decl(find_path, SUDOERS_DEBUG_UTIL)
if (strlen(infile) >= PATH_MAX) {
errno = ENAMETOOLONG;
debug_return_int(NOT_FOUND_ERROR);
}
/*
* If we were given a fully qualified or relative path
* there is no need to look at $PATH.
*/
if (strchr(infile, '/') != NULL) {
strlcpy(command, infile, sizeof(command)); /* paranoia */
if (sudo_goodpath(command, sbp)) {
*outfile = command;
debug_return_int(FOUND);
} else
debug_return_int(NOT_FOUND);
if (strlcpy(command, infile, sizeof(command)) >= sizeof(command)) {
errno = ENAMETOOLONG;
debug_return_int(NOT_FOUND_ERROR);
}
found = cmnd_allowed(command, sizeof(command), sbp, whitelist);
goto done;
}
if (path == NULL)
@@ -106,7 +148,8 @@ find_path(const char *infile, char **outfile, struct stat *sbp,
errno = ENAMETOOLONG;
debug_return_int(NOT_FOUND_ERROR);
}
if ((found = sudo_goodpath(command, sbp)))
found = cmnd_allowed(command, sizeof(command), sbp, whitelist);
if (found)
break;
}
@@ -119,14 +162,16 @@ find_path(const char *infile, char **outfile, struct stat *sbp,
errno = ENAMETOOLONG;
debug_return_int(NOT_FOUND_ERROR);
}
found = sudo_goodpath(command, sbp);
found = cmnd_allowed(command, sizeof(command), sbp, whitelist);
if (found && ignore_dot)
debug_return_int(NOT_FOUND_DOT);
}
done:
if (found) {
*outfile = command;
if ((*outfile = strdup(command)) == NULL)
debug_return_int(NOT_FOUND_ERROR);
debug_return_int(FOUND);
} else
debug_return_int(NOT_FOUND);
}
debug_return_int(NOT_FOUND);
}