dash.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Herbert Xu <herbert@gondor.apana.org.au>
To: DASH Mailing List <dash@vger.kernel.org>
Subject: [PATCH] input: Fix potential out-of-bounds read in popstring
Date: Thu, 2 May 2024 18:22:20 +0800	[thread overview]
Message-ID: <ZjNpXKnES43hHImN@gondor.apana.org.au> (raw)

For an empty alias, the check on the last character of the alias in
popstring may read a bogus byte.  Fix this by checking whether the
alias is empty or not before reading the last byte.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
 src/input.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/input.c b/src/input.c
index fb9858f..e56ab5f 100644
--- a/src/input.c
+++ b/src/input.c
@@ -401,7 +401,7 @@ static void popstring(void)
 	struct strpush *sp = parsefile->strpush;
 
 	INTOFF;
-	if (sp->ap) {
+	if (sp->ap && parsefile->nextc > sp->string) {
 		if (parsefile->nextc[-1] == ' ' ||
 		    parsefile->nextc[-1] == '\t') {
 			checkkwd |= CHKALIAS;
-- 
2.39.2

-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

                 reply	other threads:[~2024-05-02 10:22 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=ZjNpXKnES43hHImN@gondor.apana.org.au \
    --to=herbert@gondor.apana.org.au \
    --cc=dash@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
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).