- nicm@cvs.openbsd.org 2010/10/08 21:48:42

     [openbsd-compat/glob.c]
     Extend GLOB_LIMIT to cover readdir and stat and bump the malloc limit
     from ARG_MAX to 64K.
     Fixes glob-using programs (notably ftp) able to be triggered to hit
     resource limits.
     Idea from a similar NetBSD change, original problem reported by jasper@.
     ok millert tedu jasper

1 files changed, 63 insertions, 39 deletions

diff --git a/openbsd-compat/glob.c b/openbsd-compat/glob.c
index e52bef729..692e81045 100644
--- a/openbsd-compat/glob.c
+++ b/openbsd-compat/glob.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: glob.c,v 1.33 2010/09/26 22:15:39 djm Exp $ */
+/*      $OpenBSD: glob.c,v 1.34 2010/10/08 21:48:42 nicm Exp $ */
 /*
  * Copyright (c) 1989, 1993
  *      The Regents of the University of California.  All rights reserved.
@@ -76,18 +76,6 @@
     !defined(HAVE_DECL_GLOB_NOMATCH) || HAVE_DECL_GLOB_NOMATCH == 0 || \
     defined(BROKEN_GLOB)
 
-static long
-get_arg_max(void)
-{
-#ifdef ARG_MAX
-        return(ARG_MAX);
-#elif defined(HAVE_SYSCONF) && defined(_SC_ARG_MAX)
-        return(sysconf(_SC_ARG_MAX));
-#else
-        return(256); /* XXX: arbitrary */
-#endif
-}
-
 #include "charclass.h"
 
 #define DOLLAR          '$'
@@ -140,6 +128,15 @@ typedef char Char;
 #define M_CLASS         META(':')
 #define ismeta(c)       (((c)&M_QUOTE) != 0)
 
+#define GLOB_LIMIT_MALLOC       65536
+#define GLOB_LIMIT_STAT         128
+#define GLOB_LIMIT_READDIR      16384
+
+struct glob_lim {
+        size_t  glim_malloc;
+        size_t  glim_stat;
+        size_t  glim_readdir;
+};
 
 static int       compare(const void *, const void *);
 static int       g_Ctoc(const Char *, char *, u_int);
@@ -148,17 +145,19 @@ static DIR	*g_opendir(Char *, glob_t *);
 static Char     *g_strchr(const Char *, int);
 static int       g_strncmp(const Char *, const char *, size_t);
 static int       g_stat(Char *, struct stat *, glob_t *);
-static int       glob0(const Char *, glob_t *);
-static int       glob1(Char *, Char *, glob_t *, size_t *);
+static int       glob0(const Char *, glob_t *, struct glob_lim *);
+static int       glob1(Char *, Char *, glob_t *, struct glob_lim *);
 static int       glob2(Char *, Char *, Char *, Char *, Char *, Char *,
-                    glob_t *, size_t *);
+                    glob_t *, struct glob_lim *);
 static int       glob3(Char *, Char *, Char *, Char *, Char *,
-                    Char *, Char *, glob_t *, size_t *);
-static int       globextend(const Char *, glob_t *, size_t *, struct stat *);
+                    Char *, Char *, glob_t *, struct glob_lim *);
+static int       globextend(const Char *, glob_t *, struct glob_lim *,
+                    struct stat *);
 static const Char *
                  globtilde(const Char *, Char *, size_t, glob_t *);
-static int       globexp1(const Char *, glob_t *);
-static int       globexp2(const Char *, const Char *, glob_t *);
+static int       globexp1(const Char *, glob_t *, struct glob_lim *);
+static int       globexp2(const Char *, const Char *, glob_t *,
+                    struct glob_lim *);
 static int       match(Char *, Char *, Char *);
 #ifdef DEBUG
 static void      qprintf(const char *, Char *);
@@ -171,6 +170,7 @@ glob(const char *pattern, int flags, int (*errfunc)(const char *, int),
         const u_char *patnext;
         int c;
         Char *bufnext, *bufend, patbuf[MAXPATHLEN];
+        struct glob_lim limit = { 0, 0, 0 };
 
         patnext = (u_char *) pattern;
         if (!(flags & GLOB_APPEND)) {
@@ -204,9 +204,9 @@ glob(const char *pattern, int flags, int (*errfunc)(const char *, int),
         *bufnext = EOS;
 
         if (flags & GLOB_BRACE)
-                return globexp1(patbuf, pglob);
+                return globexp1(patbuf, pglob, &limit);
         else
-                return glob0(patbuf, pglob);
+                return glob0(patbuf, pglob, &limit);
 }
 
 /*
@@ -215,18 +215,18 @@ glob(const char *pattern, int flags, int (*errfunc)(const char *, int),
  * characters
  */
 static int
-globexp1(const Char *pattern, glob_t *pglob)
+globexp1(const Char *pattern, glob_t *pglob, struct glob_lim *limitp)
 {
         const Char* ptr = pattern;
 
         /* Protect a single {}, for find(1), like csh */
         if (pattern[0] == LBRACE && pattern[1] == RBRACE && pattern[2] == EOS)
-                return glob0(pattern, pglob);
+                return glob0(pattern, pglob, limitp);
 
         if ((ptr = (const Char *) g_strchr(ptr, LBRACE)) != NULL)
-                return globexp2(ptr, pattern, pglob);
+                return globexp2(ptr, pattern, pglob, limitp);
 
-        return glob0(pattern, pglob);
+        return glob0(pattern, pglob, limitp);
 }
 
 
@@ -236,7 +236,8 @@ globexp1(const Char *pattern, glob_t *pglob)
  * 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)
+globexp2(const Char *ptr, const Char *pattern, glob_t *pglob,
+    struct glob_lim *limitp)
 {
         int     i, rv;
         Char   *lm, *ls;
@@ -272,7 +273,7 @@ globexp2(const Char *ptr, const Char *pattern, glob_t *pglob)
 
         /* Non matching braces; just glob the pattern */
         if (i != 0 || *pe == EOS)
-                return glob0(patbuf, pglob);
+                return glob0(patbuf, pglob, limitp);
 
         for (i = 0, pl = pm = ptr; pm <= pe; pm++) {
                 switch (*pm) {
@@ -318,7 +319,7 @@ globexp2(const Char *ptr, const Char *pattern, glob_t *pglob)
 #ifdef DEBUG
                                 qprintf("globexp2:", patbuf);
 #endif
-                                rv = globexp1(patbuf, pglob);
+                                rv = globexp1(patbuf, pglob, limitp);
                                 if (rv && rv != GLOB_NOMATCH)
                                         return rv;
 
@@ -449,12 +450,11 @@ g_charclass(const Char **patternp, Char **bufnextp)
  * to find no matches.
  */
 static int
-glob0(const Char *pattern, glob_t *pglob)
+glob0(const Char *pattern, glob_t *pglob, struct glob_lim *limitp)
 {
         const Char *qpatnext;
         int c, err, oldpathc;
         Char *bufnext, patbuf[MAXPATHLEN];
-        size_t limit = 0;
 
         qpatnext = globtilde(pattern, patbuf, MAXPATHLEN, pglob);
         oldpathc = pglob->gl_pathc;
@@ -526,7 +526,7 @@ glob0(const Char *pattern, glob_t *pglob)
         qprintf("glob0:", patbuf);
 #endif
 
-        if ((err = glob1(patbuf, patbuf+MAXPATHLEN-1, pglob, &limit)) != 0)
+        if ((err = glob1(patbuf, patbuf+MAXPATHLEN-1, pglob, limitp)) != 0)
                 return(err);
 
         /*
@@ -539,7 +539,7 @@ glob0(const Char *pattern, glob_t *pglob)
                 if ((pglob->gl_flags & GLOB_NOCHECK) ||
                     ((pglob->gl_flags & GLOB_NOMAGIC) &&
                     !(pglob->gl_flags & GLOB_MAGCHAR)))
-                        return(globextend(pattern, pglob, &limit, NULL));
+                        return(globextend(pattern, pglob, limitp, NULL));
                 else
                         return(GLOB_NOMATCH);
         }
@@ -556,7 +556,7 @@ compare(const void *p, const void *q)
 }
 
 static int
-glob1(Char *pattern, Char *pattern_last, glob_t *pglob, size_t *limitp)
+glob1(Char *pattern, Char *pattern_last, glob_t *pglob, struct glob_lim *limitp)
 {
         Char pathbuf[MAXPATHLEN];
 
@@ -575,7 +575,7 @@ glob1(Char *pattern, Char *pattern_last, glob_t *pglob, size_t *limitp)
  */
 static int
 glob2(Char *pathbuf, Char *pathbuf_last, Char *pathend, Char *pathend_last,
-    Char *pattern, Char *pattern_last, glob_t *pglob, size_t *limitp)
+    Char *pattern, Char *pattern_last, glob_t *pglob, struct glob_lim *limitp)
 {
         struct stat sb;
         Char *p, *q;
@@ -591,6 +591,14 @@ glob2(Char *pathbuf, Char *pathbuf_last, Char *pathend, Char *pathend_last,
                         if (g_lstat(pathbuf, &sb, pglob))
                                 return(0);
 
+                        if ((pglob->gl_flags & GLOB_LIMIT) &&
+                            limitp->glim_stat++ >= GLOB_LIMIT_STAT) {
+                                errno = 0;
+                                *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) &&
@@ -636,7 +644,7 @@ glob2(Char *pathbuf, Char *pathbuf_last, Char *pathend, Char *pathend_last,
 static int
 glob3(Char *pathbuf, Char *pathbuf_last, Char *pathend, Char *pathend_last,
     Char *pattern, Char *restpattern, Char *restpattern_last, glob_t *pglob,
-    size_t *limitp)
+    struct glob_lim *limitp)
 {
         struct dirent *dp;
         DIR *dirp;
@@ -679,6 +687,14 @@ glob3(Char *pathbuf, Char *pathbuf_last, Char *pathend, Char *pathend_last,
                 u_char *sc;
                 Char *dc;
 
+                if ((pglob->gl_flags & GLOB_LIMIT) &&
+                    limitp->glim_readdir++ >= GLOB_LIMIT_READDIR) {
+                        errno = 0;
+                        *pathend++ = SEP;
+                        *pathend = EOS;
+                        return(GLOB_NOSPACE);
+                }
+
                 /* Initial DOT must be matched literally. */
                 if (dp->d_name[0] == DOT && *pattern != DOT)
                         continue;
@@ -725,7 +741,8 @@ glob3(Char *pathbuf, Char *pathbuf_last, Char *pathend, Char *pathend_last,
  *      gl_pathv points to (gl_offs + gl_pathc + 1) items.
  */
 static int
-globextend(const Char *path, glob_t *pglob, size_t *limitp, struct stat *sb)
+globextend(const Char *path, glob_t *pglob, struct glob_lim *limitp,
+    struct stat *sb)
 {
         char **pathv;
         ssize_t i;
@@ -781,6 +798,12 @@ globextend(const Char *path, glob_t *pglob, size_t *limitp, struct stat *sb)
                 if (sb == NULL)
                         statv[pglob->gl_offs + pglob->gl_pathc] = NULL;
                 else {
+                        limitp->glim_malloc += sizeof(**statv);
+                        if ((pglob->gl_flags & GLOB_LIMIT) &&
+                            limitp->glim_malloc >= GLOB_LIMIT_MALLOC) {
+                                errno = 0;
+                                return(GLOB_NOSPACE);
+                        }
                         if ((statv[pglob->gl_offs + pglob->gl_pathc] =
                             malloc(sizeof(**statv))) == NULL)
                                 goto copy_error;
@@ -793,7 +816,7 @@ globextend(const Char *path, glob_t *pglob, size_t *limitp, struct stat *sb)
         for (p = path; *p++;)
                 ;
         len = (size_t)(p - path);
-        *limitp += len;
+        limitp->glim_malloc += len;
         if ((copy = malloc(len)) != NULL) {
                 if (g_Ctoc(path, copy, len)) {
                         free(copy);
@@ -804,7 +827,8 @@ globextend(const Char *path, glob_t *pglob, size_t *limitp, struct stat *sb)
         pathv[pglob->gl_offs + pglob->gl_pathc] = NULL;
 
         if ((pglob->gl_flags & GLOB_LIMIT) &&
-            (newn * sizeof(*pathv)) + *limitp >= (u_int) get_arg_max()) {
+            (newn * sizeof(*pathv)) + limitp->glim_malloc >
+            GLOB_LIMIT_MALLOC) {
                 errno = 0;
                 return(GLOB_NOSPACE);
         }