From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 6C58B19F43A; Sat, 12 Oct 2024 11:26:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728732410; cv=none; b=qVWq7UqZCv8T8y8VQca2vlbn1Jpvg0OZkd3Mu9+k0pKAUIpFHVbwO2BaiHLxrrYOljVCx+ZwBIYfDh13KXtQxDRDe9EpEGnoQ0g+mD0Mdis+wjChCFSkN+AdUSZ0miNHQLGj8bce4F1W1+BB/g/MzV/qPMXcu6srmBkTAwnTmS0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728732410; c=relaxed/simple; bh=n4puN3NXxZUnE6ck5tpzUeGwM7AWiitHgrBK4NNHBgI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=faRMBrlkONQIT8qp3OOLwADzGdKYe+ClBb/yaPqDai8JFK5U+ryFbJ3mE/VW3kcElNAk9RwIwN7VJZZ+RXM5WWEOHjlURt0/BsE0loWjDJ1sjEyulfdB7C61Q62o6STERAk3f8jAxl8EDYjOUVkWZ/T6IuFMyie8RcgKWTy3llg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=r8u6zS9h; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="r8u6zS9h" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8225C4CEC7; Sat, 12 Oct 2024 11:26:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728732409; bh=n4puN3NXxZUnE6ck5tpzUeGwM7AWiitHgrBK4NNHBgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r8u6zS9hHHYK12h5Y8tSgI//y7Rq4/RWFiyKI7Svl0f+Bf2caHlPu0ZTf7CYa61f+ aZK9c8cRj7MAoULASHKqrG0tdy1FsQNXEoyLowAh1Ld46x97pq5B33+GbqG+Y/9tFC Hf/TBoaSE7g/JuswJr1BNicfmSucnWaJckI1fQjZ3vxrGSyrJvDRDxrErOsClBW8iQ fFhWDVsG0u2xRPJfDHaGSuk8lx1sen9HFgik/0qxShO6Chilo0Rvjda4ZoIXkCYGao tH6UeYBzwJ9G/i16p9sU3kxWXLNAvAAe4rlZcYqy7zUYpiyZrFtcP3IHTgi77bBb8m 3xZFD8O/I2NZA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Pali=20Roh=C3=A1r?= , Paulo Alcantara , Steve French , Sasha Levin , sfrench@samba.org, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org Subject: [PATCH AUTOSEL 6.11 15/16] cifs: Validate content of NFS reparse point buffer Date: Sat, 12 Oct 2024 07:26:11 -0400 Message-ID: <20241012112619.1762860-15-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241012112619.1762860-1-sashal@kernel.org> References: <20241012112619.1762860-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-cifs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.11.3 Content-Transfer-Encoding: 8bit From: Pali Rohár [ Upstream commit 556ac52bb1e76cc28fd30aa117b42989965b3efd ] Symlink target location stored in DataBuffer is encoded in UTF-16. So check that symlink DataBuffer length is non-zero and even number. And check that DataBuffer does not contain UTF-16 null codepoint because Linux cannot process symlink with null byte. DataBuffer for char and block devices is 8 bytes long as it contains two 32-bit numbers (major and minor). Add check for this. DataBuffer buffer for sockets and fifos zero-length. Add checks for this. Signed-off-by: Pali Rohár Reviewed-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/smb/client/reparse.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c index ad0e0de9a165d..7429b96a6ae5e 100644 --- a/fs/smb/client/reparse.c +++ b/fs/smb/client/reparse.c @@ -330,6 +330,18 @@ static int parse_reparse_posix(struct reparse_posix_data *buf, switch ((type = le64_to_cpu(buf->InodeType))) { case NFS_SPECFILE_LNK: + if (len == 0 || (len % 2)) { + cifs_dbg(VFS, "srv returned malformed nfs symlink buffer\n"); + return -EIO; + } + /* + * Check that buffer does not contain UTF-16 null codepoint + * because Linux cannot process symlink with null byte. + */ + if (UniStrnlen((wchar_t *)buf->DataBuffer, len/2) != len/2) { + cifs_dbg(VFS, "srv returned null byte in nfs symlink target location\n"); + return -EIO; + } data->symlink_target = cifs_strndup_from_utf16(buf->DataBuffer, len, true, cifs_sb->local_nls); @@ -340,8 +352,19 @@ static int parse_reparse_posix(struct reparse_posix_data *buf, break; case NFS_SPECFILE_CHR: case NFS_SPECFILE_BLK: + /* DataBuffer for block and char devices contains two 32-bit numbers */ + if (len != 8) { + cifs_dbg(VFS, "srv returned malformed nfs buffer for type: 0x%llx\n", type); + return -EIO; + } + break; case NFS_SPECFILE_FIFO: case NFS_SPECFILE_SOCK: + /* DataBuffer for fifos and sockets is empty */ + if (len != 0) { + cifs_dbg(VFS, "srv returned malformed nfs buffer for type: 0x%llx\n", type); + return -EIO; + } break; default: cifs_dbg(VFS, "%s: unhandled inode type: 0x%llx\n", -- 2.43.0