parent
b724a90dc7
commit
6201214506
@ -0,0 +1,42 @@
|
|||||||
|
From 4b7d9cd4a018898d7714ce06f3faf2626c14582b Mon Sep 17 00:00:00 2001
|
||||||
|
From: Werner Koch <wk@gnupg.org>
|
||||||
|
Date: Wed, 5 Oct 2022 14:19:06 +0200
|
||||||
|
Subject: [PATCH] Detect a possible overflow directly in the TLV parser.
|
||||||
|
|
||||||
|
* src/ber-help.c (_ksba_ber_read_tl): Check for overflow of a commonly
|
||||||
|
used sum.
|
||||||
|
--
|
||||||
|
|
||||||
|
It is quite common to have checks like
|
||||||
|
|
||||||
|
if (ti.nhdr + ti.length >= DIM(tmpbuf))
|
||||||
|
return gpg_error (GPG_ERR_TOO_LARGE);
|
||||||
|
|
||||||
|
This patch detects possible integer overflows immmediately when
|
||||||
|
creating the TI object.
|
||||||
|
|
||||||
|
Reported-by: ZDI-CAN-18927, ZDI-CAN-18928, ZDI-CAN-18929
|
||||||
|
---
|
||||||
|
src/ber-help.c | 6 ++++++
|
||||||
|
1 file changed, 6 insertions(+)
|
||||||
|
|
||||||
|
diff --git a/src/ber-help.c b/src/ber-help.c
|
||||||
|
index 81c31ed..56efb6a 100644
|
||||||
|
--- a/src/ber-help.c
|
||||||
|
+++ b/src/ber-help.c
|
||||||
|
@@ -182,6 +182,12 @@ _ksba_ber_read_tl (ksba_reader_t reader, struct tag_info *ti)
|
||||||
|
ti->length = len;
|
||||||
|
}
|
||||||
|
|
||||||
|
+ if (ti->length > ti->nhdr && (ti->nhdr + ti->length) < ti->length)
|
||||||
|
+ {
|
||||||
|
+ ti->err_string = "header+length would overflow";
|
||||||
|
+ return gpg_error (GPG_ERR_EOVERFLOW);
|
||||||
|
+ }
|
||||||
|
+
|
||||||
|
/* Without this kludge some example certs can't be parsed */
|
||||||
|
if (ti->class == CLASS_UNIVERSAL && !ti->tag)
|
||||||
|
ti->length = 0;
|
||||||
|
--
|
||||||
|
2.37.3
|
||||||
|
|
Loading…
Reference in new issue