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 27810531629; Wed, 23 Sep 2026 14:54:23 +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=1790175264; cv=none; b=h4rTHT47PlJoOFuMGL3yFHUmdzS+ipWXYA8ufkFVJ6g0EATit2x4YgAHmvl/fxGwuMB2Oa17QLnjkiBcwNaYhHnJn/504W+Vs1Ikz/6KexiCw95j9KJs6268gk7sPTRi8MBjtsviqgf1x3BmugRQtldmZxxZ0rx7aWZCneYdHcE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790175264; c=relaxed/simple; bh=7/sKlONbzjkiOOUJCNnkB61IvTBmVg1vjqQx+TRac+w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Kn//iT6b9fEJVAIgvIs9pWR2G4Nk2dkp6/z9FBvFROCunXkWon72K4viAZw6zrQTYxtildDmvRojsgC5D4PTlY9N886+ayReP9XR7su47meCS59iTYP7Cn5sV0Js49EwW/3JNXIEiAGDs9CEW59JeGA3DuwAg0M2fsGH7Oc8oBk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IW57IxH/; 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="IW57IxH/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A0441F000FF; Wed, 23 Sep 2026 14:54:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790175263; bh=jec1eXUnJIFEPPAU8ZKEILBbOZow3qE9AVOCq53d3Rw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=IW57IxH/f/p+YS3gaShE+dT1xKZTOnyGD8OGAlHQi559Xxko12AZRfrcjUmKOWa8p kltM7xuq7+OAr/B4HQyQ0D1QoiUXbL24sIjRZs89S8nV9GVisZgU3gjDzUDJrtE56z GZghdB6jlkqK6IyYdIkn4iR/lB2IUtHeTAAv8uWU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Frank Sorenson , David Howells , Paulo Alcantara Subject: [PATCH 6.18 355/398] smb: client: fix missing lower-bound check on DFS referral string offsets Date: Wed, 23 Sep 2026 16:07:09 +0200 Message-ID: <20260923140652.631776382@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Frank Sorenson commit e83330c55edc0c3ac08aa6c95e49e4694c65523b upstream. parse_dfs_referrals() checks that DfsPathOffset and NetworkAddressOffset do not exceed the buffer end, but fails to check that they don't point inside the referral header itself. If a server provides an offset smaller than sizeof(struct dfs_referral_level_3), the derived string pointer overlaps with the struct fields, causing cifs_strndup_from_utf16() to interpret header data as UTF-16 strings. Fix this by enforcing that string offsets are at least sizeof(*ref). Fixes: 4ecce920e13a ("CIFS: move DFS response parsing out of SMB1 code") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson Reviewed-by: David Howells Signed-off-by: Paulo Alcantara Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/misc.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/fs/smb/client/misc.c +++ b/fs/smb/client/misc.c @@ -1050,7 +1050,11 @@ parse_dfs_referrals(struct get_dfs_refer node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags); /* copy DfsPath */ - if (le16_to_cpu(ref->DfsPathOffset) > data_end - (char *)ref) { + if (le16_to_cpu(ref->DfsPathOffset) < sizeof(*ref) || + le16_to_cpu(ref->DfsPathOffset) > data_end - (char *)ref) { + cifs_dbg(VFS, "%s: DfsPathOffset %u out of range [%zu, %td]\n", + __func__, le16_to_cpu(ref->DfsPathOffset), + sizeof(*ref), data_end - (char *)ref); rc = -EINVAL; goto parse_DFS_referrals_exit; } @@ -1064,7 +1068,11 @@ parse_dfs_referrals(struct get_dfs_refer } /* copy link target UNC */ - if (le16_to_cpu(ref->NetworkAddressOffset) > data_end - (char *)ref) { + if (le16_to_cpu(ref->NetworkAddressOffset) < sizeof(*ref) || + le16_to_cpu(ref->NetworkAddressOffset) > data_end - (char *)ref) { + cifs_dbg(VFS, "%s: NetworkAddressOffset %u out of range [%zu, %td]\n", + __func__, le16_to_cpu(ref->NetworkAddressOffset), + sizeof(*ref), data_end - (char *)ref); rc = -EINVAL; goto parse_DFS_referrals_exit; }