From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E1FAB386C1C; Tue, 21 Jul 2026 20:52:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784667172; cv=none; b=bdaw3lX05Q6XrwmrZQj/0iD+r4mBOF8YXx1+CRNveL29dq3jhRgr6OuwIFxJs7pwfKujjAnBRlTXhm0oAt2lHN7WCtekoVpX7+am4RKUrg/lOtDukSt8vAAjI49CzeyUXlevjTkFenrnx/tDyUNEWviFgxSRZUf/23I3DXM7fv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784667172; c=relaxed/simple; bh=4q4g3nhft87dDa4Wkw3VEaEDyC38DtxkimCswDMmKNw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VWj5sMHSuT0yLbkyg3DGFTIc3gFd6k33ZtD62ysN/wVGeKQR9bwTrQhTHTbCzMrUdIiaE8MLP5BGyumJ9U1QYQIvLRaNOODjEh9b9mzSHfuXdH2/k87WRFYYe5VqvBuw4ua/5iieVMokJe94jaGf375ZpGHszi1Ba49C9uvVWpk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eOTICFTp; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="eOTICFTp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E3C61F000E9; Tue, 21 Jul 2026 20:52:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784667170; bh=XGvmQqVRGwlVLX/0onkyUC9H/lYpsxdv6EWQ/nZYcD4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eOTICFTppZRWbfmvBGXriZ3ugUy9Cc2qajJ1JabErlUHG9Iw9Mpeq4bSVR281LV54 ln2OghdR37jX+q8XFw74w/M8Ie2Df2QefvWK/Ifl0H/cE2cypU7Syboxx4IQJWFG1N e8ElnUQZ1kKfqGJ7AusbGosrwRxFtHsuoftnqPA0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Muhammad Bilal , Florian Westphal Subject: [PATCH 6.6 0923/1266] netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read Date: Tue, 21 Jul 2026 17:22:40 +0200 Message-ID: <20260721152502.492240276@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152441.786066624@linuxfoundation.org> References: <20260721152441.786066624@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Muhammad Bilal commit ef6400ca25a13fd6dedbe8ef4a1d0979bbbfe88a upstream. parse_dcc() treats data_end as an inclusive end pointer, but its only caller passes data_limit = ib_ptr + datalen, which points one past the last valid byte. The newline search loop iterates while tmp <= data_end, so when no newline is present, *tmp is read at tmp == data_end, one byte beyond the region filled by skb_header_pointer(). irc_buffer is kmalloc'd as MAX_SEARCH_SIZE + 1 bytes and datalen is capped at MAX_SEARCH_SIZE, so the stray read does not fault. The byte is uninitialized or stale; if it contains an ASCII digit, simple_strtoul will consume it and produce a wrong DCC IP or port in the conntrack expectation. The extra allocation byte is also a fragile guard: if the cap or allocation size changes, this becomes a real out-of-bounds read. Change the loop and its post-loop check to use strict less-than, consistent with the caller's exclusive-end convention. Update the function comment accordingly. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal Signed-off-by: Florian Westphal Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_conntrack_irc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/net/netfilter/nf_conntrack_irc.c +++ b/net/netfilter/nf_conntrack_irc.c @@ -64,7 +64,7 @@ static const char *const dccprotos[] = { /* tries to get the ip_addr and port out of a dcc command * return value: -1 on failure, 0 on success * data pointer to first byte of DCC command data - * data_end pointer to last byte of dcc command data + * data_end one past end of data * ip returns parsed ip of dcc command * port returns parsed port of dcc command * ad_beg_p returns pointer to first byte of addr data @@ -82,10 +82,10 @@ static int parse_dcc(char *data, const c /* Make sure we have a newline character within the packet boundaries * because simple_strtoul parses until the first invalid character. */ - for (tmp = data; tmp <= data_end; tmp++) + for (tmp = data; tmp < data_end; tmp++) if (*tmp == '\n') break; - if (tmp > data_end || *tmp != '\n') + if (tmp >= data_end || *tmp != '\n') return -1; *ad_beg_p = data;