|
 |
a2cf7d |
commit ddc650e9b3dc916eab417ce9f79e67337b05035c
|
|
|
a2cf7d |
Author: Andreas Schwab <schwab@suse.de>
|
|
|
a2cf7d |
Date: Wed Feb 19 17:21:46 2020 +0100
|
|
|
a2cf7d |
|
|
|
a2cf7d |
Fix use-after-free in glob when expanding ~user (bug 25414)
|
|
|
a2cf7d |
|
|
|
a2cf7d |
The value of `end_name' points into the value of `dirname', thus don't
|
|
|
a2cf7d |
deallocate the latter before the last use of the former.
|
|
|
a2cf7d |
|
|
|
a2cf7d |
diff --git a/posix/glob.c b/posix/glob.c
|
|
|
a2cf7d |
index cba9cd1819..4580cefb9f 100644
|
|
|
a2cf7d |
--- a/posix/glob.c
|
|
|
a2cf7d |
+++ b/posix/glob.c
|
|
|
a2cf7d |
@@ -827,31 +827,32 @@ __glob (const char *pattern, int flags, int (*errfunc) (const char *, int),
|
|
|
a2cf7d |
{
|
|
|
a2cf7d |
size_t home_len = strlen (p->pw_dir);
|
|
|
a2cf7d |
size_t rest_len = end_name == NULL ? 0 : strlen (end_name);
|
|
|
a2cf7d |
- char *d;
|
|
|
a2cf7d |
+ char *d, *newp;
|
|
|
a2cf7d |
+ bool use_alloca = glob_use_alloca (alloca_used,
|
|
|
a2cf7d |
+ home_len + rest_len + 1);
|
|
|
a2cf7d |
|
|
|
a2cf7d |
- if (__glibc_unlikely (malloc_dirname))
|
|
|
a2cf7d |
- free (dirname);
|
|
|
a2cf7d |
- malloc_dirname = 0;
|
|
|
a2cf7d |
-
|
|
|
a2cf7d |
- if (glob_use_alloca (alloca_used, home_len + rest_len + 1))
|
|
|
a2cf7d |
- dirname = alloca_account (home_len + rest_len + 1,
|
|
|
a2cf7d |
- alloca_used);
|
|
|
a2cf7d |
+ if (use_alloca)
|
|
|
a2cf7d |
+ newp = alloca_account (home_len + rest_len + 1, alloca_used);
|
|
|
a2cf7d |
else
|
|
|
a2cf7d |
{
|
|
|
a2cf7d |
- dirname = malloc (home_len + rest_len + 1);
|
|
|
a2cf7d |
- if (dirname == NULL)
|
|
|
a2cf7d |
+ newp = malloc (home_len + rest_len + 1);
|
|
|
a2cf7d |
+ if (newp == NULL)
|
|
|
a2cf7d |
{
|
|
|
a2cf7d |
scratch_buffer_free (&pwtmpbuf);
|
|
|
a2cf7d |
retval = GLOB_NOSPACE;
|
|
|
a2cf7d |
goto out;
|
|
|
a2cf7d |
}
|
|
|
a2cf7d |
- malloc_dirname = 1;
|
|
|
a2cf7d |
}
|
|
|
a2cf7d |
- d = mempcpy (dirname, p->pw_dir, home_len);
|
|
|
a2cf7d |
+ d = mempcpy (newp, p->pw_dir, home_len);
|
|
|
a2cf7d |
if (end_name != NULL)
|
|
|
a2cf7d |
d = mempcpy (d, end_name, rest_len);
|
|
|
a2cf7d |
*d = '\0';
|
|
|
a2cf7d |
|
|
|
a2cf7d |
+ if (__glibc_unlikely (malloc_dirname))
|
|
|
a2cf7d |
+ free (dirname);
|
|
|
a2cf7d |
+ dirname = newp;
|
|
|
a2cf7d |
+ malloc_dirname = !use_alloca;
|
|
|
a2cf7d |
+
|
|
|
a2cf7d |
dirlen = home_len + rest_len;
|
|
|
a2cf7d |
dirname_modified = 1;
|
|
|
a2cf7d |
}
|