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 7D6C64AF694 for ; Thu, 3 Sep 2026 13:48:51 +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=1788443336; cv=none; b=uK/90BAIdemHHB65I4V6Dd/8vDNMDQhJr/HAQJjdP95J6zvuk88HJvY/9C8gg5Dg+k/qSd7/aCvA4ZB6tYWx9Bn6EU1V3DZi+9uQt4EjfG9zo0EnVQH6CV51vYrtSG8BI6aHMh38QFatQGVYCr6a3EYlhypHMJavbBcrfxFxng0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788443336; c=relaxed/simple; bh=vSPTn6uyFOoeOhloayFlOvAoNlE/U6WWpu9SPjrPOy4=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=JtHQsBBqyDkd2TqUQEjVykrQ2imz3Z30Eeq7jmeIUhqYK50KhipzWmoIqEk2D2zQLTu53j40WJY6XuFJtMNwJQ5Sm6AyIKof909+kdYpSroKXFGYs8ojJAy5ISgnQaR6mpdWax/T7LcVC1Bd79EhcKMFcqsRhFzA+7jImiQ6HL8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rzM+cj+W; 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="rzM+cj+W" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49B841F00A3D; Thu, 3 Sep 2026 13:48:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788443329; bh=OM4DfcLP6KbmVWtF9lB9b6JnR8xYx6iElERvsgunKGM=; h=Subject:To:Cc:From:Date; b=rzM+cj+W1AU9+HTMy8zexjy2Pa1wLchJwXdaZQGZxiFZRCsWjiCW8crYvcLDX8bRM 0aihHN+LM70eI43BO/q0UQ10L7HksMdC2ORZsYzuQRGfjfSpL24iTkETthpgt/Bt5D qskuYbjsC9CVMPN8I2Cc1yR/67SmR0/qns3eFx6k= Subject: FAILED: patch "[PATCH] smb: client: fix OOB read/write from unvalidated DataOffset" failed to apply to 6.12-stable tree To: sorenson@redhat.com,grayhat@foxmail.com,linkinjeon@kernel.org,pc@manguebit.org Cc: From: Date: Thu, 03 Sep 2026 15:27:02 +0200 Message-ID: <2026090302-baboon-occupy-7143@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 6343c1da561962688f203362d80d6a3bfa39fa1b # git commit -s git send-email --to '' --in-reply-to '2026090302-baboon-occupy-7143@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 6343c1da561962688f203362d80d6a3bfa39fa1b Mon Sep 17 00:00:00 2001 From: Frank Sorenson Date: Tue, 11 Aug 2026 21:41:26 -0500 Subject: [PATCH] smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2() coalesce_t2() computes data pointers directly from server-supplied DataOffset fields with no validation against buffer bounds: data_area_of_tgt = (char *)&pSMBt->hdr.Protocol + get_unaligned_le16(&pSMBt->t2_rsp.DataOffset); data_area_of_src = (char *)&pSMBs->hdr.Protocol + get_unaligned_le16(&pSMBs->t2_rsp.DataOffset); data_area_of_tgt += total_in_tgt; ... memcpy(data_area_of_tgt, data_area_of_src, total_in_src); A small DataOffset can push a pointer below the actual byte area, overwriting header fields; a large one can push it past the buffer end, causing out-of-bounds heap reads (source) or writes (target). The BCC overflow guard does not prevent this: BCC reflects how much data is present, while DataOffset controls where in the buffer it starts. The "validate target area" comment present since the function was first written in 2005 was a placeholder that was never implemented. Add lower- and upper-bound checks for both data pointers before the memcpy, and before any target header fields are modified. Fixes: e4eb295d38b5 ("[PATCH] cifs: Handle multiple response transact2 part 1 of 2") Cc: stable@vger.kernel.org Reported-by: Shen Yongchao Signed-off-by: Frank Sorenson Signed-off-by: Namjae Jeon Signed-off-by: Paulo Alcantara diff --git a/fs/smb/client/smb1transport.c b/fs/smb/client/smb1transport.c index 966f2cf83a51..66daa5a37e4a 100644 --- a/fs/smb/client/smb1transport.c +++ b/fs/smb/client/smb1transport.c @@ -375,12 +375,31 @@ coalesce_t2(char *second_buf, struct smb_hdr *target_hdr, unsigned int *pdu_len) data_area_of_tgt = (char *)&pSMBt->hdr.Protocol + get_unaligned_le16(&pSMBt->t2_rsp.DataOffset); - /* validate target area */ data_area_of_src = (char *)&pSMBs->hdr.Protocol + get_unaligned_le16(&pSMBs->t2_rsp.DataOffset); data_area_of_tgt += total_in_tgt; + /* + * DataOffset fields are server-supplied and not validated against + * buffer bounds; check both data pointers before mutating the + * target header. + */ + if (data_area_of_tgt < (char *)target_hdr + + sizeof(struct smb_t2_rsp) + sizeof(__le16) || + data_area_of_tgt + total_in_src > + (char *)target_hdr + CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) { + cifs_dbg(VFS, "%s: target data area out of bounds\n", __func__); + return -EPROTO; + } + if (data_area_of_src < second_buf + + sizeof(struct smb_t2_rsp) + sizeof(__le16) || + data_area_of_src + total_in_src > + second_buf + smbCalcSize((struct smb_hdr *)second_buf)) { + cifs_dbg(VFS, "%s: secondary data area out of bounds\n", __func__); + return -EPROTO; + } + total_in_tgt += total_in_src; /* is the result too big for the field? */ if (total_in_tgt > USHRT_MAX) {