From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 02 Apr 2026 09:21:56 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1w8CNI-007lha-2k for lore@lore.pengutronix.de; Thu, 02 Apr 2026 09:21:56 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1w8CNI-0008Sd-9q for lore@pengutronix.de; Thu, 02 Apr 2026 09:21:56 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:To:In-Reply-To: References:Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version: Subject:Date:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=2eh0Z210BkhlqHTzEj0M+Wz7aFg7zzeLVZ3OgsS/gIk=; b=TMRCk+qGyt47ezbKyBMlrcZzJG +/vo5oj6Y+JgeNhBPuHG2d2xq7YL5TlTSaKGTvPhagEfG9lQwhwcfDs2FLgySjixoI70IyzV6BACz 76khCTB/2ojBdGbjKU1+10NPgCyPp/6GmO7MFBMNAORk4NqMgTSS7bkB0OF9X0pQCmcbYhCIbGwNx gTec0ND4HnrYus90DPe05JsDRDwPUz5rx8rrQde6xCd7M+5gboy9zt+EZRa+XOoGvSPRxpzY/ls/W zUo6t4QmFwV+/NEukdEex+EfkyC6nGwzjvy5rhHRhdcjsY0H3TdQEiY3SDwgtsoZhNpJdaA8OXA8a BEiJxabQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w8CMv-0000000H2LP-1wsN; Thu, 02 Apr 2026 07:21:33 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w8CMt-0000000H2IT-0zkj for barebox@lists.infradead.org; Thu, 02 Apr 2026 07:21:32 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1w8CMj-0008De-Pt; Thu, 02 Apr 2026 09:21:21 +0200 Received: from dude02.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::28]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1w8CMj-003Kwf-1i; Thu, 02 Apr 2026 09:21:21 +0200 Received: from [::1] (helo=dude02.red.stw.pengutronix.de) by dude02.red.stw.pengutronix.de with esmtp (Exim 4.98.2) (envelope-from ) id 1w8CMj-00000003PEH-1p07; Thu, 02 Apr 2026 09:21:21 +0200 From: Sascha Hauer Date: Thu, 02 Apr 2026 09:21:20 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260402-net-tftp-buffer-overflows-v1-2-0a18aa8ea19e@pengutronix.de> References: <20260402-net-tftp-buffer-overflows-v1-0-0a18aa8ea19e@pengutronix.de> In-Reply-To: <20260402-net-tftp-buffer-overflows-v1-0-0a18aa8ea19e@pengutronix.de> To: BAREBOX X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1775114481; l=1360; i=s.hauer@pengutronix.de; s=20230412; h=from:subject:message-id; bh=YDOZzRonDR2CSma/d08pFSvqQRQooSi3CGzoCArUY68=; b=0thNPCN42IKspYXUr7kRjx+UH9cqrmy7yjTQ3tpjhBVj4VYkSDAi+g9iVm9VVZiAnhxsg1Orz 3LH5eZWK8zTABxaalfKVv1TvgFiA9PvAxZd3M4ou/5JVMswOUccAxKk X-Developer-Key: i=s.hauer@pengutronix.de; a=ed25519; pk=4kuc9ocmECiBJKWxYgqyhtZOHj5AWi7+d0n/UjhkwTg= X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260402_002131_283992_6D22F877 X-CRM114-Status: GOOD ( 12.73 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Claude Opus 4.6 \(1M context\)" Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.2 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH 2/4] fs: tftp: fix OACK option parsing bounds check X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) The bounds check in tftp_parse_oack() uses 'val > s + len' to detect when the value pointer exceeds the packet. Since 's' advances through the buffer while 'len' stays constant, 's + len' always points past 'pkt + len', making the check always false — it is dead code. The forced null at pkt[len - 1] provides partial protection, but when the last option key ends exactly at pkt[len - 1], val equals pkt + len and the subsequent strlen(val) reads past the packet boundary into uninitialized packet buffer data. Fix by checking 'val >= pkt + len' instead, which correctly bounds val against the actual end of the packet data. Using >= because when val equals pkt + len there is no room for a value string. Signed-off-by: Sascha Hauer Co-Authored-By: Claude Opus 4.6 (1M context) --- fs/tftp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/tftp.c b/fs/tftp.c index 1b15bc18e7..03e9d552aa 100644 --- a/fs/tftp.c +++ b/fs/tftp.c @@ -370,7 +370,7 @@ static int tftp_parse_oack(struct file_priv *priv, unsigned char *pkt, int len) while (s < pkt + len) { opt = s; val = s + strlen(s) + 1; - if (val > s + len) + if (val >= pkt + len) break; if (!strcmp(opt, "tsize")) priv->filesize = simple_strtoull(val, NULL, 10); -- 2.47.3