From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1AE79171A1 for ; Mon, 8 May 2023 11:34:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8719DC433D2; Mon, 8 May 2023 11:34:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683545641; bh=uaQj6qaJKTou4wOcaqUrvKjY4OgH/StKaKWp2CT6UBs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qVvTBLUO2gxQp5Q0YQK7QZtodaZ+D6xQkghw2pqGWiB8xUBt/DB/njtuiVkCZu9ff gHqyzqDKczvV07z5XpHpDp/L/jd/K1LQcpVJIaXO9nXM27B/tKCMn8fHo4/nHBQckt kH5ApBH288GtHzA3RhRSpj2VoT85ovijw4qxfOEs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 5.15 107/371] media: av7110: prevent underflow in write_ts_to_decoder() Date: Mon, 8 May 2023 11:45:08 +0200 Message-Id: <20230508094816.271079699@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094811.912279944@linuxfoundation.org> References: <20230508094811.912279944@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Dan Carpenter [ Upstream commit eed9496a0501357aa326ddd6b71408189ed872eb ] The buf[4] value comes from the user via ts_play(). It is a value in the u8 range. The final length we pass to av7110_ipack_instant_repack() is "len - (buf[4] + 1) - 4" so add a check to ensure that the length is not negative. It's not clear that passing a negative len value does anything bad necessarily, but it's not best practice. With the new bounds checking the "if (!len)" condition is no longer possible or required so remove that. Fixes: fd46d16d602a ("V4L/DVB (11759): dvb-ttpci: Add TS replay capability") Signed-off-by: Dan Carpenter Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/staging/media/av7110/av7110_av.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/staging/media/av7110/av7110_av.c b/drivers/staging/media/av7110/av7110_av.c index 91f4866c7e59b..964092e2f41fd 100644 --- a/drivers/staging/media/av7110/av7110_av.c +++ b/drivers/staging/media/av7110/av7110_av.c @@ -823,10 +823,10 @@ static int write_ts_to_decoder(struct av7110 *av7110, int type, const u8 *buf, s av7110_ipack_flush(ipack); if (buf[3] & ADAPT_FIELD) { + if (buf[4] > len - 1 - 4) + return 0; len -= buf[4] + 1; buf += buf[4] + 1; - if (!len) - return 0; } av7110_ipack_instant_repack(buf + 4, len - 4, ipack); -- 2.39.2