+2019-06-10 Bruno Haible <bruno@clisp.org>
+
+ posix_spawn_file_actions_addopen: Fix possible use-after-free bug.
+ Reported at <https://sourceware.org/bugzilla/show_bug.cgi?id=17048>.
+ * lib/spawn_int.h (struct __spawn_action): Remove 'const' from path.
+ * lib/spawn_faction_addopen.c (posix_spawn_file_actions_addopen): Make
+ a copy of the path argument.
+ * lib/spawn_faction_destroy.c (posix_spawn_file_actions_destroy): Free
+ it.
+
2019-06-10 Bruno Haible <bruno@clisp.org>
posix_spawn_file_actions_addfchdir: Add tests.
#include <spawn.h>
#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
#include <unistd.h>
#if !_LIBC
#if !REPLACE_POSIX_SPAWN
return posix_spawn_file_actions_addopen (file_actions, fd, path, oflag, mode);
#else
- /* Allocate more memory if needed. */
- if (file_actions->_used == file_actions->_allocated
- && __posix_spawn_file_actions_realloc (file_actions) != 0)
- /* This can only mean we ran out of memory. */
- return ENOMEM;
-
{
- struct __spawn_action *rec;
+ /* Copy PATH, because the caller may free it before calling posix_spawn()
+ or posix_spawnp(). */
+ char *path_copy = strdup (path);
+ if (path_copy == NULL)
+ return ENOMEM;
+
+ /* Allocate more memory if needed. */
+ if (file_actions->_used == file_actions->_allocated
+ && __posix_spawn_file_actions_realloc (file_actions) != 0)
+ {
+ /* This can only mean we ran out of memory. */
+ free (path_copy);
+ return ENOMEM;
+ }
+
+ {
+ struct __spawn_action *rec;
- /* Add the new value. */
- rec = &file_actions->_actions[file_actions->_used];
- rec->tag = spawn_do_open;
- rec->action.open_action.fd = fd;
- rec->action.open_action.path = path;
- rec->action.open_action.oflag = oflag;
- rec->action.open_action.mode = mode;
+ /* Add the new value. */
+ rec = &file_actions->_actions[file_actions->_used];
+ rec->tag = spawn_do_open;
+ rec->action.open_action.fd = fd;
+ rec->action.open_action.path = path_copy;
+ rec->action.open_action.oflag = oflag;
+ rec->action.open_action.mode = mode;
- /* Account for the new entry. */
- ++file_actions->_used;
+ /* Account for the new entry. */
+ ++file_actions->_used;
- return 0;
+ return 0;
+ }
}
#endif
}
#include <stdlib.h>
+#if REPLACE_POSIX_SPAWN
+# include "spawn_int.h"
+#endif
+
/* Initialize data structure for file attribute for 'spawn' call. */
int
posix_spawn_file_actions_destroy (posix_spawn_file_actions_t *file_actions)
+#undef posix_spawn_file_actions_destroy
{
- /* Free the memory allocated. */
+#if !REPLACE_POSIX_SPAWN
+ return posix_spawn_file_actions_destroy (file_actions);
+#else
+ int i;
+
+ /* Free the paths in the open actions. */
+ for (i = 0; i < file_actions->_used; ++i)
+ {
+ struct __spawn_action *sa = &file_actions->_actions[i];
+ switch (sa->tag)
+ {
+ case spawn_do_open:
+ free (sa->action.open_action.path);
+ break;
+ default:
+ /* No cleanup required. */
+ break;
+ }
+ }
+
+ /* Free the array of actions. */
free (file_actions->_actions);
+
return 0;
+#endif
}