diff options
| author | Tom Lane | 2015-09-18 17:55:17 +0000 |
|---|---|---|
| committer | Tom Lane | 2015-09-18 17:55:17 +0000 |
| commit | d9c0c728afe734b7087dbb9a4bc16d5b682d139d (patch) | |
| tree | 4dfb0df17031d0ae480869b4278a22a4352fbc3d | |
| parent | d63a1720fa0b2ca8452c3a2aa2f6ddbb4f05b640 (diff) | |
Fix low-probability memory leak in regex execution.
After an internal failure in shortest() or longest() while pinning down the
exact location of a match, find() forgot to free the DFA structure before
returning. This is pretty unlikely to occur, since we just successfully
ran the "search" variant of the DFA; but it could happen, and it would
result in a session-lifespan memory leak since this code uses malloc()
directly. Problem seems to have been aboriginal in Spencer's library,
so back-patch all the way.
In passing, correct a thinko in a comment I added awhile back about the
meaning of the "ntree" field.
I happened across these issues while comparing our code to Tcl's version
of the library.
| -rw-r--r-- | src/backend/regex/regcomp.c | 2 | ||||
| -rw-r--r-- | src/backend/regex/regexec.c | 6 | ||||
| -rw-r--r-- | src/include/regex/regguts.h | 2 |
3 files changed, 7 insertions, 3 deletions
diff --git a/src/backend/regex/regcomp.c b/src/backend/regex/regcomp.c index 6b95975f2b..d137ac0d3d 100644 --- a/src/backend/regex/regcomp.c +++ b/src/backend/regex/regcomp.c @@ -228,7 +228,7 @@ struct vars struct subre *tree; /* subexpression tree */ struct subre *treechain; /* all tree nodes allocated */ struct subre *treefree; /* any free tree nodes */ - int ntree; /* number of tree nodes */ + int ntree; /* number of tree nodes, plus one */ struct cvec *cv; /* interface cvec */ struct cvec *cv2; /* utility cvec */ struct subre *lacons; /* lookahead-constraint vector */ diff --git a/src/backend/regex/regexec.c b/src/backend/regex/regexec.c index efd1e9ba02..8505994747 100644 --- a/src/backend/regex/regexec.c +++ b/src/backend/regex/regexec.c @@ -348,7 +348,11 @@ find(struct vars * v, (chr **) NULL, &hitend); else end = longest(v, d, begin, v->stop, &hitend); - NOERR(); + if (ISERR()) + { + freedfa(d); + return v->err; + } if (hitend && cold == NULL) cold = begin; if (end != NULL) diff --git a/src/include/regex/regguts.h b/src/include/regex/regguts.h index 94e06f041b..fccaf298bf 100644 --- a/src/include/regex/regguts.h +++ b/src/include/regex/regguts.h @@ -467,7 +467,7 @@ struct guts size_t nsub; /* copy of re_nsub */ struct subre *tree; struct cnfa search; /* for fast preliminary search */ - int ntree; /* number of subre's, less one */ + int ntree; /* number of subre's, plus one */ struct colormap cmap; int FUNCPTR(compare, (const chr *, const chr *, size_t)); struct subre *lacons; /* lookahead-constraint vector */ |