From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793210466; b=xNsG7++gk5fZuwG90lYt7oXzmK+fo4FMmElwFJXoDnDZXidjf7C0L5uqzhdOFWxBqsGM HR9BtV59iwAwskCwnrbha4ix0Hwj+5WbNsBNYEbRXORUtoCNUMTyNigREZOvKTqxJpUGW VkVM2oxwoBEgAUaWACuCqWfRdmzTMp1IqMIdTUagjMe6YXqy5PsZHvy/THqswGpwmBU9D bgOTaeFIRWQWjkyCUYPSmMYCehv0QqtvNKM3BEJVB090SgIMdPk6K7d4DauklIetUsNUH msilJxxyGJNgxpwOI5h+ng838+hA8i95jo4Ycy71tb2wUZEnaemiCl8Vq1z1NJ+Woxw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210466; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=ewsBD4zvIviVNYMtvtQVhrp6RipyFNwt448wmVU4Jrs=; b=yk2mY1XXpKI2dP3VpqFRucuGiM1ZTZZNIf5lorFUX2+xoDkLcymYZGw4axKFYgq/DKvZ CLyEivOXDGONYi3ovW7UGRdkbQnJianpyHnhZaQzl4u4hE6zEs5T74kHHQJ/7KKO7l3Zt RzfNmYWN5flFxU0GlKyqvrAc/hdYMskL9ZmXCYvWKs5IoImaTM7utPTcgfGPGYvegCVsw 6lfoQDHb4+q9hXwSjJCb4uqmk+LUqymaspiGJ9PqfqVb96YGC4323Hk4kAU8KgpbsHi06 eReUPKTPC30UBgclIbvF37hkqAXWknk3m/rKA2XjGgvaezXZ9xXV+Sw6LBZxphJTNvQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=NdYNCbOj; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9F6A5606A31C; Wed, 28 Oct 2026 18:01:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=NdYNCbOj Received: by smtp.kernel.org (Postfix) with ESMTPSA id A28D91F01825; Wed, 28 Oct 2026 18:01:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210466; bh=ewsBD4zvIviVNYMtvtQVhrp6RipyFNwt448wmVU4Jrs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NdYNCbOjQ077HlWO/PadYjAlNE1e+1FLQQ11XbSgt9ht8IF8vDd2vXmqQKCg0DWmi Oo15ypkQ3/kivPoWezxliCf8aIMOC/hdL+ZDikvRKwh3ZmmiuINLi7BwRowA11fA9J YvgBjwHR1IMksm/z5cWmCC3NoVML2D3Z9TbS+7F4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shen Yongchao , Frank Sorenson , Namjae Jeon , Paulo Alcantara , Sasha Levin Subject: [PATCH 5.15 007/571] smb: client: fix OOB read/write from unvalidated DataOffset in coalesce_t2() Date: Wed, 28 Oct 2026 17:52:34 +0100 Message-ID: <20261028170008.194875054@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Frank Sorenson [ Upstream commit 6343c1da561962688f203362d80d6a3bfa39fa1b ] 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 [ transplanted the bounds validation to coalesce_t2() in smb1ops.c due to code relocation ] Signed-off-by: Sasha Levin --- fs/cifs/smb1ops.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c index 41e468d06b5b0..55aa58460dff8 100644 --- a/fs/cifs/smb1ops.c +++ b/fs/cifs/smb1ops.c @@ -319,12 +319,31 @@ coalesce_t2(char *second_buf, struct smb_hdr *target_hdr) 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) { -- 2.53.0