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=1793817318; b=QwhY8PZ9KhAW7yNYcG1OsnY+c5PokcAmbNU1ViMODHH9+CdWb9/BdiYkCS+YzdtsEuEB IBJZkyfk6aYkQcYa3C2VXMhDdSVgHftXWuvu0ec73a4b9NfGHny2lvCUFtLIXeW53Pjpo 8agTSJzEr/xNS8101hWUH6QmPrtRT0LPY4kEKCXUPwZ7o3ataQwsDsVpiBG/bi8N9n6Nj +FOioq1eOcZ2tZ0TbqwKHuoOjwka5XI6oKOptx7+P6dMpmaPamiGkRGb54pujPfpkz8MF w22gHTz8xIqWLt89ZsfIkiM2v9smyAsF/Uq0h0+CN2CHTVbEW5uxx0H5cI+rYWgnZew== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793817318; h=Received:DKIM-Signature:Subject:To:Cc:From:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=okVViN6tsS06CSiIw+DJzbOVljyr3WA1xIxF/YC18Wg=; b=EEUFHlFOenwVvMMXXkf/vVeMIK4xj4ZTaupus5jApun+HtOW36A39FiPxwT+VyKZjrXv Wq4dxKWqUVKb5qsQpukZawEsN5WgCit0Qk/LBaEyw7ycSdO02vI8BD9Fw1IiXwHpvSYfY fO9nG0cbd3cfZO0NZ862AHz7OodydB0A3NrYuux9tJ3sjhWxLGWfOCZNCoH6R9DBs8j9c AdqdPLGy/ljvDO0by9FWaB5lqRIlnTdO/DJjg27MOFeJyCE1eDfMTrkijPsG5eMNfDpCX DCceDAc3swhzDlcvJ61AEM9WYTpXcnJ2kvvYotCrPz1RrEcxWVTndOrIfvgS8rpzR5w== 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=TGPR2eMT; 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 10626606A329 for ; Wed, 4 Nov 2026 18:35:18 +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=TGPR2eMT Received: by smtp.kernel.org (Postfix) with ESMTPSA id A05581F000C1; Wed, 4 Nov 2026 18:35:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793817317; bh=okVViN6tsS06CSiIw+DJzbOVljyr3WA1xIxF/YC18Wg=; h=Subject:To:Cc:From:Date; b=TGPR2eMTV9I8FcCcaLF504oMlOSGtL8aoXu3XnDnATDURkr3pf+fmmT2V3ojlDJ/F dI2Do1rqsR1hZnVYNeoX8V9W9DHJ6+CWalRb71KnjDK1396Pl45/PJnTcXZ9HXA4rY ycuqML7GR3HLd5/iNW5mkzZgQ08F4GEzjJreFCsI= Subject: FAILED: patch "[PATCH] smb: client: validate SMB1 EA list bounds before parsing" failed to apply to 5.10-stable tree To: ratnaker.gautam@kuleuven.be,pc@manguebit.org Cc: From: Date: Wed, 04 Nov 2026 13:35:09 -0500 Message-ID: <2026110409-unsoiled-surging-adc6@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list 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 5.10-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-5.10.y git checkout FETCH_HEAD git cherry-pick -x ddc7a7e1eeb116ccaf010a6f1fb6ab927f3f888d # git commit -s git send-email --to '' --in-reply-to '2026110409-unsoiled-surging-adc6@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ddc7a7e1eeb116ccaf010a6f1fb6ab927f3f888d Mon Sep 17 00:00:00 2001 From: Ratnaker Gautam Date: Sat, 24 Oct 2026 12:36:14 +0000 Subject: [PATCH] smb: client: validate SMB1 EA list bounds before parsing CIFSSMBQAllEAs() checks the server-provided EA list length by adding it to the response pointer. On 32-bit systems, a positive length can wrap the pointer and pass the comparison. The parser then walks outside the received response while reading the next FEA header. A response with a list length of 0x40000000 reproduces this as a native i386 page fault and kernel panic from listxattr() against an SMB1 server. Check that the EA list starts within the SMB byte area before reading its header. Keep its length unsigned and compare it with the bytes left in the response without pointer addition. SMB1 is not negotiated by default and requires an explicit vers=1.0 mount. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Ratnaker Gautam Signed-off-by: Paulo Alcantara diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 9ffc94ac2069..2936b38de98f 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -6215,9 +6215,11 @@ CIFSSMBQAllEAs(const unsigned int xid, struct cifs_tcon *tcon, int rc = 0; int bytes_returned; int list_len; + u32 ea_list_len; struct fealist *ea_response_data; struct fea *temp_fea; char *temp_ptr; + char *byte_area; char *end_of_smb; __u16 params, byte_count, data_offset; unsigned int ea_name_len = ea_name ? strlen(ea_name) : 0; @@ -6296,9 +6298,19 @@ CIFSSMBQAllEAs(const unsigned int xid, struct cifs_tcon *tcon, ea_response_data = (struct fealist *) (((char *) &pSMBr->hdr.Protocol) + data_offset); - list_len = le32_to_cpu(ea_response_data->list_len); - cifs_dbg(FYI, "ea length %d\n", list_len); - if (list_len <= 8) { + byte_area = pByteArea(&pSMBr->hdr); + end_of_smb = byte_area + get_bcc(&pSMBr->hdr); + if ((char *)ea_response_data < byte_area || + (char *)ea_response_data > + end_of_smb - sizeof(ea_response_data->list_len)) { + rc = smb_EIO2(smb_eio_trace_qalleas_overlong, + data_offset, get_bcc(&pSMBr->hdr)); + goto QAllEAsOut; + } + + ea_list_len = le32_to_cpu(ea_response_data->list_len); + cifs_dbg(FYI, "%s: ea length: %u\n", __func__, ea_list_len); + if (ea_list_len <= 8) { cifs_dbg(FYI, "empty EA list returned from server\n"); /* didn't find the named attribute */ if (ea_name) @@ -6307,14 +6319,14 @@ CIFSSMBQAllEAs(const unsigned int xid, struct cifs_tcon *tcon, } /* make sure list_len doesn't go past end of SMB */ - end_of_smb = (char *)pByteArea(&pSMBr->hdr) + get_bcc(&pSMBr->hdr); - if ((char *)ea_response_data + list_len > end_of_smb) { + if (ea_list_len > end_of_smb - (char *)ea_response_data) { cifs_dbg(FYI, "EA list appears to go beyond SMB\n"); rc = smb_EIO2(smb_eio_trace_qalleas_overlong, - (unsigned long)ea_response_data + list_len - (unsigned long)pSMBr, - (unsigned long)end_of_smb - (unsigned long)pSMBr); + ea_list_len, + end_of_smb - (char *)ea_response_data); goto QAllEAsOut; } + list_len = ea_list_len; /* account for ea list len */ list_len -= 4;