From patchwork Sun Sep 29 18:50:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Pali_Roh=C3=A1r?= X-Patchwork-Id: 13815200 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 8DBBD55E53; Sun, 29 Sep 2024 18:51:04 +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=1727635864; cv=none; b=CPKU4JIBzqnKm+FbVD+9ZInU5RZ2Mz2VbarcL3yK+QnC8QCxTX/ARvh7EX5Cc0AycwZXlOEbWq+Be/KsmOinqtUyeF0X6gh0KMD7nPOmTIbdRQPYfukUTKZEiximX9c3CBl4s4Lq7RLHaMofy5WX/pu1fXnXt5ccJKO8IcWj9l4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727635864; c=relaxed/simple; bh=Smyda09QytiOgtvr5vHjvB5Eoa2wj8kkQxDlMltOPVc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=dgMzePpfK05sYtk7GaJO07CarK4YWTTGs0mTQ8XpEbZRJSwyJFJLVxhT+T9bb1a6xShnWZZjG4YHxTK7t2/uCj3jQtXWmyzf4ZfwP4jToU8EKX80bPFOPhoG/xQPuCRTOVPYRFY16fI+DXgzOJBlNH+wmKzqA8rBYJQm0tbh8ZY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O/cO4g/P; 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="O/cO4g/P" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 505D0C4CED3; Sun, 29 Sep 2024 18:51:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727635864; bh=Smyda09QytiOgtvr5vHjvB5Eoa2wj8kkQxDlMltOPVc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O/cO4g/Preg7vgqyLNL0va0+bR5lIBuPmwau3eVoDZE6OBjEvYRdM/3yROaG2aRfH TRWHXuWBUhIqsdB+4JUF4C/HcgAd4vE6ghFAvG0BQHggy7Eo6C8jx7v6AZ4ud0hhvW ZfePehDszOswj9dh9ZqcO4wYsdeASoC1En9mrhZo1UF6HifTDFKYRWdSdnvMO1qCLT DIaWNBffj6XzAD2t24hVuI8l6QRGAxLX2Gvd5vQSO1QXUlOQBRnOooQr0CAi2hubAJ g5reDm/G/DeEO7DUxe44B7QTYdcGq4Dff17gxst13u0PRlJpcN/wY9JtkQ6Dvd9sqq vLb/K6oQ8sxLw== Received: by pali.im (Postfix) id 07ACFD48; Sun, 29 Sep 2024 20:50:58 +0200 (CEST) From: =?utf-8?q?Pali_Roh=C3=A1r?= To: Steve French , Paulo Alcantara , Ronnie Sahlberg Cc: linux-cifs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 6/7] cifs: Validate content of native symlink Date: Sun, 29 Sep 2024 20:50:52 +0200 Message-Id: <20240929185053.10554-7-pali@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20240929185053.10554-1-pali@kernel.org> References: <20240929185053.10554-1-pali@kernel.org> Precedence: bulk X-Mailing-List: linux-cifs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Check that buffer does not contain UTF-16 null codepoint because Linux cannot process symlink with null byte. Signed-off-by: Pali Rohár --- fs/smb/client/reparse.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/smb/client/reparse.c b/fs/smb/client/reparse.c index 5a738f65b190..ca4f96c43508 100644 --- a/fs/smb/client/reparse.c +++ b/fs/smb/client/reparse.c @@ -509,6 +509,16 @@ int smb2_parse_native_symlink(char **target, const char *buf, unsigned int len, int rc; int i; + /* + * Check that buffer does not contain UTF-16 null codepoint + * because Linux cannot process symlink with null byte. + */ + if (unicode && UniStrnlen((wchar_t *)buf, len/2) != len/2) { + cifs_dbg(VFS, "srv returned null byte in native symlink target location\n"); + rc = -EIO; + goto out; + } + smb_target = cifs_strndup_from_utf16(buf, len, unicode, cifs_sb->local_nls); if (!smb_target) { rc = -ENOMEM;