diff options
Diffstat (limited to 'lib/libc/regex/regcomp.c')
| -rw-r--r-- | lib/libc/regex/regcomp.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/libc/regex/regcomp.c b/lib/libc/regex/regcomp.c index 2ecb88c54a93..ae92f6a3ef82 100644 --- a/lib/libc/regex/regcomp.c +++ b/lib/libc/regex/regcomp.c @@ -192,6 +192,7 @@ regcomp(regex_t * __restrict preg, struct parse *p = &pa; int i; size_t len; + size_t maxlen; #ifdef REDEBUG # define GOODFLAGS(f) (f) #else @@ -213,7 +214,23 @@ regcomp(regex_t * __restrict preg, g = (struct re_guts *)malloc(sizeof(struct re_guts)); if (g == NULL) return(REG_ESPACE); + /* + * Limit the pattern space to avoid a 32-bit overflow on buffer + * extension. Also avoid any signed overflow in case of conversion + * so make the real limit based on a 31-bit overflow. + * + * Likely not applicable on 64-bit systems but handle the case + * generically (who are we to stop people from using ~715MB+ + * patterns?). + */ + maxlen = ((size_t)-1 >> 1) / sizeof(sop) * 2 / 3; + if (len >= maxlen) { + free((char *)g); + return(REG_ESPACE); + } p->ssize = len/(size_t)2*(size_t)3 + (size_t)1; /* ugh */ + assert(p->ssize >= len); + p->strip = (sop *)malloc(p->ssize * sizeof(sop)); p->slen = 0; if (p->strip == NULL) { |