diff options
Diffstat (limited to 'src/backend/regex/regcomp.c')
| -rw-r--r-- | src/backend/regex/regcomp.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/src/backend/regex/regcomp.c b/src/backend/regex/regcomp.c index d137ac0d3d1..62f6359e345 100644 --- a/src/backend/regex/regcomp.c +++ b/src/backend/regex/regcomp.c @@ -34,7 +34,7 @@ #include "regex/regguts.h" -#include "miscadmin.h" /* needed by rcancelrequested() */ +#include "miscadmin.h" /* needed by rcancelrequested/rstacktoodeep */ /* * forward declarations, up here so forward datatypes etc. are defined early @@ -70,6 +70,7 @@ static int newlacon(struct vars *, struct state *, struct state *, int); static void freelacons(struct subre *, int); static void rfree(regex_t *); static int rcancelrequested(void); +static int rstacktoodeep(void); #ifdef REG_DEBUG static void dump(regex_t *, FILE *); @@ -152,7 +153,7 @@ static int push(struct nfa *, struct arc *); #define COMPATIBLE 3 /* compatible but not satisfied yet */ static int combine(struct arc *, struct arc *); static void fixempties(struct nfa *, FILE *); -static struct state *emptyreachable(struct state *, struct state *); +static struct state *emptyreachable(struct nfa *, struct state *, struct state *); static void replaceempty(struct nfa *, struct state *, struct state *); static void cleanup(struct nfa *); static void markreachable(struct nfa *, struct state *, struct state *, struct state *); @@ -279,7 +280,8 @@ struct vars /* static function list */ static const struct fns functions = { rfree, /* regfree insides */ - rcancelrequested /* check for cancel request */ + rcancelrequested, /* check for cancel request */ + rstacktoodeep /* check for stack getting dangerously deep */ }; @@ -1626,6 +1628,16 @@ subre(struct vars * v, { struct subre *ret = v->treefree; + /* + * Checking for stack overflow here is sufficient to protect parse() and + * its recursive subroutines. + */ + if (STACK_TOO_DEEP(v->re)) + { + ERR(REG_ETOOBIG); + return NULL; + } + if (ret != NULL) v->treefree = ret->left; else @@ -1938,6 +1950,22 @@ rcancelrequested(void) return InterruptPending && (QueryCancelPending || ProcDiePending); } +/* + * rstacktoodeep - check for stack getting dangerously deep + * + * Return nonzero to fail the operation with error code REG_ETOOBIG, + * zero to keep going + * + * The current implementation is Postgres-specific. If we ever get around + * to splitting the regex code out as a standalone library, there will need + * to be some API to let applications define a callback function for this. + */ +static int +rstacktoodeep(void) +{ + return stack_is_too_deep(); +} + #ifdef REG_DEBUG /* |