* mandoc: Do not abuse assert(3) to react to absurd input; the purpose of
@ 2020-09-09 13:45 schwarze
0 siblings, 0 replies; only message in thread
From: schwarze @ 2020-09-09 13:45 UTC (permalink / raw)
To: source
Log Message:
-----------
Do not abuse assert(3) to react to absurd input; the purpose of assert(3)
only is to catch internal inconsistencies in the program itself.
Issue found in an afl run performed by Jan Schreiber <jes at posteo dot de>.
Instead, just cut down unreasonably wide spacing requested by the document
to a narrower width.
Modified Files:
--------------
mandoc:
term_ascii.c
Revision Data
-------------
Index: term_ascii.c
===================================================================
RCS file: /home/cvs/mandoc/mandoc/term_ascii.c,v
retrieving revision 1.65
retrieving revision 1.66
diff -Lterm_ascii.c -Lterm_ascii.c -u -p -r1.65 -r1.66
--- term_ascii.c
+++ term_ascii.c
@@ -245,7 +245,14 @@ ascii_advance(struct termp *p, size_t le
{
size_t i;
- assert(len < UINT16_MAX);
+ /*
+ * XXX We used to have "assert(len < UINT16_MAX)" here.
+ * that is not quite right because the input document
+ * can trigger that by merely providing large input.
+ * For now, simply truncate.
+ */
+ if (len > 256)
+ len = 256;
for (i = 0; i < len; i++)
putchar(' ');
}
@@ -383,7 +390,14 @@ locale_advance(struct termp *p, size_t l
{
size_t i;
- assert(len < UINT16_MAX);
+ /*
+ * XXX We used to have "assert(len < UINT16_MAX)" here.
+ * that is not quite right because the input document
+ * can trigger that by merely providing large input.
+ * For now, simply truncate.
+ */
+ if (len > 256)
+ len = 256;
for (i = 0; i < len; i++)
putwchar(L' ');
}
--
To unsubscribe send an email to source+unsubscribe@mandoc.bsd.lv
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2020-09-09 13:45 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-09 13:45 mandoc: Do not abuse assert(3) to react to absurd input; the purpose of schwarze
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).