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);