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 C416D511E9D; Wed, 30 Sep 2026 16:36:51 +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=1790786212; cv=none; b=nMTQV+vIREbrdLBLjWMjMaNW3xfk3TD4D82jCPChda76lL9ENTsZ3lEeVjIbprwFXUWITli5Gb+C4vIquNRHjws4O+QU+yM0c7pKgP4ibzfCZ1e7TUM5SUm87HXhaG3ycc8StQx4Lktw4hNUFQ0qeqU6uMkSbNKXXv+TUsn4ve4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790786212; c=relaxed/simple; bh=FjWdBcIMKjK9HJGLC9/HgJC5MMu2G/dmLXBM9bZjeBE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ate+kftaFbE8FFv1AwMYp6WIE7kE4d74RZqUuY9fOxY7GdxfEKrQ5V/c09ld6zn7JVRG5reK0BtqkcfSasUso9WWEZsyjDAQOUQosJnAsI3nOnVGeHoCaPeMh8qdPTt9/y8PA6O9zh+85kgF1JbZ9v2VTXy3CpudMFEc/aKmcZU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=UkywwpKE; 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="UkywwpKE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2626E1F000FF; Wed, 30 Sep 2026 16:36:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790786211; bh=cLf+p2oz/I2Wes4ubwxCnvlDOLc0MWUwNcSXW9YxNeg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=UkywwpKEWzzs4po4HX/j3MCQEB9ccFsW9Am0T33T62EBJAvcGf3UVGBumWCJ2GzIj oIHCv9fLCfIHj9AAHyJClxDG0EB3Ci4kPF4O1NNOg/4AKrw5j47K/Mq0X5bIxQqk+t J0SoDi/1Rd6gjgzQG60YcP2UxJhInxVZl/9Vpb6A= 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 6.1 780/982] smb: client: fix missing lower-bound check on DFS referral string offsets Date: Wed, 30 Sep 2026 17:25:16 +0200 Message-ID: <20260930152433.509243056@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152416.775402466@linuxfoundation.org> References: <20260930152416.775402466@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 6.1-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 @@ -1005,7 +1005,11 @@ 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; } @@ -1019,7 +1023,11 @@ 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; }