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doc/website/static/security/patches/SA-13:02/libc.patch
Sergio Carlavilla Delgado 989d921f5d Migrate doc to Hugo/AsciiDoctor 
I'm very pleased to announce the release of
our new website and documentation using
the new toolchain with Hugo and AsciiDoctor.

To get more information about the new toolchain
please read the FreeBSD Documentation Project Primer[1],
Hugo docs[2] and AsciiDoctor docs[3].

Acknowledgment:
Benedict Reuschling <bcr@>
Glen Barber <gjb@>
Hiroki Sato <hrs@>
Li-Wen Hsu <lwhsu@>
Sean Chittenden <seanc@>
The FreeBSD Foundation

[1] https://docs.FreeBSD.org/en/books/fdp-primer/
[2] https://gohugo.io/documentation/
[3] https://docs.asciidoctor.org/home/

Approved by:    doceng, core
2021-01-26 00:31:29 +01:00

215 lines
6.8 KiB
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Index: lib/libc/gen/glob.c
===================================================================
--- lib/libc/gen/glob.c (revision 246357)
+++ lib/libc/gen/glob.c (working copy)
@@ -94,6 +94,25 @@ __FBSDID("$FreeBSD$");
#include "collate.h"
+/*
+ * glob(3) expansion limits. Stop the expansion if any of these limits
+ * is reached. This caps the runtime in the face of DoS attacks. See
+ * also CVE-2010-2632
+ */
+#define GLOB_LIMIT_BRACE 128 /* number of brace calls */
+#define GLOB_LIMIT_PATH 65536 /* number of path elements */
+#define GLOB_LIMIT_READDIR 16384 /* number of readdirs */
+#define GLOB_LIMIT_STAT 1024 /* number of stat system calls */
+#define GLOB_LIMIT_STRING ARG_MAX /* maximum total size for paths */
+
+struct glob_limit {
+ size_t l_brace_cnt;
+ size_t l_path_lim;
+ size_t l_readdir_cnt;
+ size_t l_stat_cnt;
+ size_t l_string_cnt;
+};
+
#define DOLLAR '$'
#define DOT '.'
#define EOS '\0'
@@ -153,15 +172,18 @@ static const Char *g_strchr(const Char *, wchar_t)
static Char *g_strcat(Char *, const Char *);
#endif
static int g_stat(Char *, struct stat *, glob_t *);
-static int glob0(const Char *, glob_t *, size_t *);
-static int glob1(Char *, glob_t *, size_t *);
-static int glob2(Char *, Char *, Char *, Char *, glob_t *, size_t *);
-static int glob3(Char *, Char *, Char *, Char *, Char *, glob_t *, size_t *);
-static int globextend(const Char *, glob_t *, size_t *);
-static const Char *
+static int glob0(const Char *, glob_t *, struct glob_limit *);
+static int glob1(Char *, glob_t *, struct glob_limit *);
+static int glob2(Char *, Char *, Char *, Char *, glob_t *,
+ struct glob_limit *);
+static int glob3(Char *, Char *, Char *, Char *, Char *, glob_t *,
+ struct glob_limit *);
+static int globextend(const Char *, glob_t *, struct glob_limit *);
+static const Char *
globtilde(const Char *, Char *, size_t, glob_t *);
-static int globexp1(const Char *, glob_t *, size_t *);
-static int globexp2(const Char *, const Char *, glob_t *, int *, size_t *);
+static int globexp1(const Char *, glob_t *, struct glob_limit *);
+static int globexp2(const Char *, const Char *, glob_t *, int *,
+ struct glob_limit *);
static int match(Char *, Char *, Char *);
#ifdef DEBUG
static void qprintf(const char *, Char *);
@@ -171,8 +193,8 @@ int
glob(const char * __restrict pattern, int flags,
int (*errfunc)(const char *, int), glob_t * __restrict pglob)
{
+ struct glob_limit limit = { 0, 0, 0, 0, 0 };
const char *patnext;
- size_t limit;
Char *bufnext, *bufend, patbuf[MAXPATHLEN], prot;
mbstate_t mbs;
wchar_t wc;
@@ -186,11 +208,10 @@ glob(const char * __restrict pattern, int flags,
pglob->gl_offs = 0;
}
if (flags & GLOB_LIMIT) {
- limit = pglob->gl_matchc;
- if (limit == 0)
- limit = ARG_MAX;
- } else
- limit = 0;
+ limit.l_path_lim = pglob->gl_matchc;
+ if (limit.l_path_lim == 0)
+ limit.l_path_lim = GLOB_LIMIT_PATH;
+ }
pglob->gl_flags = flags & ~GLOB_MAGCHAR;
pglob->gl_errfunc = errfunc;
pglob->gl_matchc = 0;
@@ -243,11 +264,17 @@ glob(const char * __restrict pattern, int flags,
* characters
*/
static int
-globexp1(const Char *pattern, glob_t *pglob, size_t *limit)
+globexp1(const Char *pattern, glob_t *pglob, struct glob_limit *limit)
{
const Char* ptr = pattern;
int rv;
+ if ((pglob->gl_flags & GLOB_LIMIT) &&
+ limit->l_brace_cnt++ >= GLOB_LIMIT_BRACE) {
+ errno = 0;
+ return (GLOB_NOSPACE);
+ }
+
/* Protect a single {}, for find(1), like csh */
if (pattern[0] == LBRACE && pattern[1] == RBRACE && pattern[2] == EOS)
return glob0(pattern, pglob, limit);
@@ -266,7 +293,8 @@ static int
* If it fails then it tries to glob the rest of the pattern and returns.
*/
static int
-globexp2(const Char *ptr, const Char *pattern, glob_t *pglob, int *rv, size_t *limit)
+globexp2(const Char *ptr, const Char *pattern, glob_t *pglob, int *rv,
+ struct glob_limit *limit)
{
int i;
Char *lm, *ls;
@@ -436,7 +464,7 @@ globtilde(const Char *pattern, Char *patbuf, size_
* if things went well, nonzero if errors occurred.
*/
static int
-glob0(const Char *pattern, glob_t *pglob, size_t *limit)
+glob0(const Char *pattern, glob_t *pglob, struct glob_limit *limit)
{
const Char *qpatnext;
int err;
@@ -529,7 +557,7 @@ compare(const void *p, const void *q)
}
static int
-glob1(Char *pattern, glob_t *pglob, size_t *limit)
+glob1(Char *pattern, glob_t *pglob, struct glob_limit *limit)
{
Char pathbuf[MAXPATHLEN];
@@ -547,7 +575,7 @@ static int
*/
static int
glob2(Char *pathbuf, Char *pathend, Char *pathend_last, Char *pattern,
- glob_t *pglob, size_t *limit)
+ glob_t *pglob, struct glob_limit *limit)
{
struct stat sb;
Char *p, *q;
@@ -563,6 +591,15 @@ glob2(Char *pathbuf, Char *pathend, Char *pathend_
if (g_lstat(pathbuf, &sb, pglob))
return(0);
+ if ((pglob->gl_flags & GLOB_LIMIT) &&
+ limit->l_stat_cnt++ >= GLOB_LIMIT_STAT) {
+ errno = 0;
+ if (pathend + 1 > pathend_last)
+ return (GLOB_ABORTED);
+ *pathend++ = SEP;
+ *pathend = EOS;
+ return (GLOB_NOSPACE);
+ }
if (((pglob->gl_flags & GLOB_MARK) &&
pathend[-1] != SEP) && (S_ISDIR(sb.st_mode)
|| (S_ISLNK(sb.st_mode) &&
@@ -606,7 +643,7 @@ glob2(Char *pathbuf, Char *pathend, Char *pathend_
static int
glob3(Char *pathbuf, Char *pathend, Char *pathend_last,
Char *pattern, Char *restpattern,
- glob_t *pglob, size_t *limit)
+ glob_t *pglob, struct glob_limit *limit)
{
struct dirent *dp;
DIR *dirp;
@@ -652,6 +689,19 @@ glob3(Char *pathbuf, Char *pathend, Char *pathend_
size_t clen;
mbstate_t mbs;
+ if ((pglob->gl_flags & GLOB_LIMIT) &&
+ limit->l_readdir_cnt++ >= GLOB_LIMIT_READDIR) {
+ errno = 0;
+ if (pathend + 1 > pathend_last)
+ err = GLOB_ABORTED;
+ else {
+ *pathend++ = SEP;
+ *pathend = EOS;
+ err = GLOB_NOSPACE;
+ }
+ break;
+ }
+
/* Initial DOT must be matched literally. */
if (dp->d_name[0] == DOT && *pattern != DOT)
continue;
@@ -702,14 +752,15 @@ glob3(Char *pathbuf, Char *pathend, Char *pathend_
* gl_pathv points to (gl_offs + gl_pathc + 1) items.
*/
static int
-globextend(const Char *path, glob_t *pglob, size_t *limit)
+globextend(const Char *path, glob_t *pglob, struct glob_limit *limit)
{
char **pathv;
size_t i, newsize, len;
char *copy;
const Char *p;
- if (*limit && pglob->gl_pathc > *limit) {
+ if ((pglob->gl_flags & GLOB_LIMIT) &&
+ pglob->gl_matchc > limit->l_path_lim) {
errno = 0;
return (GLOB_NOSPACE);
}
@@ -737,6 +788,12 @@ static int
for (p = path; *p++;)
continue;
len = MB_CUR_MAX * (size_t)(p - path); /* XXX overallocation */
+ limit->l_string_cnt += len;
+ if ((pglob->gl_flags & GLOB_LIMIT) &&
+ limit->l_string_cnt >= GLOB_LIMIT_STRING) {
+ errno = 0;
+ return (GLOB_NOSPACE);
+ }
if ((copy = malloc(len)) != NULL) {
if (g_Ctoc(path, copy, len)) {
free(copy);
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