From d000375944e8ec965486cf019c3f75f4c06a4e10 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20=C4=8Cern=C3=BD?= <jcerny@redhat.com>
Date: Thu, 3 Feb 2022 14:14:21 +0100
Subject: [PATCH 1/5] Prevent file permissions errors
The sysctl setting `fs.protected_regular` doesn't allow `O_CREAT` open
on regular files that we don't own in world writable sticky directories
(think `/tmp`). This causes permission denied error when writing HTML
report to a temporary files created by the `mktemp` command executed as
a normal user and then executing `sudo oscap`.
See https://bugzilla.redhat.com/show_bug.cgi?id=2048571
If OpenSCAP fails to open the file because of permissions, it will retry
to open the file without O_CREAT flag.
This fixes only creation of the HTML report using the `--report` option,
We will have to create a similar patch also for other output options
such as `--results` or `--results-arf`.
---
src/source/xslt.c | 40 ++++++++++++++++++++++++++++------------
1 file changed, 28 insertions(+), 12 deletions(-)
diff --git a/src/source/xslt.c b/src/source/xslt.c
index 24c4c46e9..7a3a3f328 100644
--- a/src/source/xslt.c
+++ b/src/source/xslt.c
@@ -22,6 +22,7 @@
#include <config.h>
#endif
+#include <fcntl.h>
#include <libxml/parser.h>
#include <libxslt/xslt.h>
#include <libxslt/xsltInternals.h>
@@ -82,23 +83,38 @@ static int xccdf_ns_xslt_workaround(xmlDocPtr doc, xmlNodePtr node)
static inline int save_stylesheet_result_to_file(xmlDoc *resulting_doc, xsltStylesheet *stylesheet, const char *outfile)
{
- FILE *f = NULL;
- if (outfile)
- f = fopen(outfile, "w");
- else
- f = stdout;
-
- if (f == NULL) {
- oscap_seterr(OSCAP_EFAMILY_OSCAP, "Could not open output file '%s'", outfile ? outfile : "stdout");
- return -1;
+ int fd = STDOUT_FILENO;
+ if (outfile) {
+#ifdef OS_WINDOWS
+ fd = open(outfile, O_WRONLY|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE);
+#else
+ fd = open(outfile, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
+#endif
+ if (fd == -1) {
+ if (errno == EACCES) {
+ /* File already exists and we aren't allowed to create a new one
+ with the same name */
+#ifdef OS_WINDOWS
+ fd = open(outfile, O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE);
+#else
+ fd = open(outfile, O_WRONLY|O_TRUNC, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
+#endif
+ }
+ if (fd == -1) {
+ oscap_seterr(OSCAP_EFAMILY_OSCAP,
+ "Could not open output file '%s': %s",
+ outfile, strerror(errno));
+ return -1;
+ }
+ }
}
- int ret = xsltSaveResultToFile(f, resulting_doc, stylesheet);
+ int ret = xsltSaveResultToFd(fd, resulting_doc, stylesheet);
if (ret < 0) {
oscap_seterr(OSCAP_EFAMILY_OSCAP, "Could not save result document");
}
- if (outfile && f)
- fclose(f);
+ if (fd != STDOUT_FILENO)
+ close(fd);
return ret;
}
From ad3c89a72c0aeb6c6ceab0873c51b07deba45701 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20=C4=8Cern=C3=BD?= <jcerny@redhat.com>
Date: Thu, 3 Feb 2022 15:08:52 +0100
Subject: [PATCH 2/5] Prevent permission access issues
Very similar to the previous commit, but this time for saving XML
documents.
---
src/common/elements.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/src/common/elements.c b/src/common/elements.c
index e512f5e3d..d0d9170f1 100644
--- a/src/common/elements.c
+++ b/src/common/elements.c
@@ -233,9 +233,22 @@ int oscap_xml_save_filename(const char *filename, xmlDocPtr doc)
int fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY,
S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
#endif
- if (fd < 0) {
- oscap_seterr(OSCAP_EFAMILY_GLIBC, "%s '%s'", strerror(errno), filename);
- return -1;
+ if (fd == -1) {
+ if (errno == EACCES) {
+ /* File already exists and we aren't allowed to create a new one
+ with the same name */
+#ifdef OS_WINDOWS
+ fd = open(filename, O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE);
+#else
+ fd = open(filename, O_WRONLY|O_TRUNC,
+ S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
+#endif
+ }
+ if (fd == -1) {
+ oscap_seterr(OSCAP_EFAMILY_GLIBC,
+ "%s '%s'", strerror(errno), filename);
+ return -1;
+ }
}
buff = xmlOutputBufferCreateFd(fd, NULL);
From b2dc90fb80419e30d05676660a2069050693078d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20=C4=8Cern=C3=BD?= <jcerny@redhat.com>
Date: Thu, 3 Feb 2022 15:37:31 +0100
Subject: [PATCH 3/5] Add a missing include
---
src/source/xslt.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/src/source/xslt.c b/src/source/xslt.c
index 7a3a3f328..a763d6b59 100644
--- a/src/source/xslt.c
+++ b/src/source/xslt.c
@@ -30,6 +30,8 @@
#include <libxslt/xsltutils.h>
#include <libexslt/exslt.h>
#include <string.h>
+#include <sys/stat.h>
+
#ifdef OS_WINDOWS
#include <io.h>
#else
From 13ff98bd744ea542bc782e388fdedb5b7f66e54b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20=C4=8Cern=C3=BD?= <jcerny@redhat.com>
Date: Thu, 3 Feb 2022 16:22:56 +0100
Subject: [PATCH 4/5] Fix missing STDOUT_FILENO on Windows
---
src/source/xslt.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/src/source/xslt.c b/src/source/xslt.c
index a763d6b59..799d5170d 100644
--- a/src/source/xslt.c
+++ b/src/source/xslt.c
@@ -85,7 +85,11 @@ static int xccdf_ns_xslt_workaround(xmlDocPtr doc, xmlNodePtr node)
static inline int save_stylesheet_result_to_file(xmlDoc *resulting_doc, xsltStylesheet *stylesheet, const char *outfile)
{
+#ifdef OS_WINDOWS
+ int fd = _fileno(stdout);
+#else
int fd = STDOUT_FILENO;
+#endif
if (outfile) {
#ifdef OS_WINDOWS
fd = open(outfile, O_WRONLY|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE);
@@ -115,7 +119,11 @@ static inline int save_stylesheet_result_to_file(xmlDoc *resulting_doc, xsltStyl
if (ret < 0) {
oscap_seterr(OSCAP_EFAMILY_OSCAP, "Could not save result document");
}
+#ifdef OS_WINDOWS
+ if (fd != _fileno(stdout))
+#else
if (fd != STDOUT_FILENO)
+#endif
close(fd);
return ret;
}
From f00831513ec2cdde13c12820ff6cc0eef8105c65 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20=C4=8Cern=C3=BD?= <jcerny@redhat.com>
Date: Fri, 4 Feb 2022 12:19:50 +0100
Subject: [PATCH 5/5] Refactor: extract function oscap_open_writable
---
src/common/elements.c | 26 ++--------------
src/common/util.c | 31 +++++++++++++++++++
src/common/util.h | 14 ++++++++-
src/source/xslt.c | 27 ++--------------
tests/API/XCCDF/unittests/CMakeLists.txt | 2 ++
tests/API/XCCDF/unittests/test_oscap_common.c | 1 +
6 files changed, 53 insertions(+), 48 deletions(-)
diff --git a/src/common/elements.c b/src/common/elements.c
index d0d9170f1..de4be88f1 100644
--- a/src/common/elements.c
+++ b/src/common/elements.c
@@ -227,29 +227,9 @@ int oscap_xml_save_filename(const char *filename, xmlDocPtr doc)
xmlCode = xmlSaveFormatFileEnc(filename, doc, "UTF-8", 1);
}
else {
-#ifdef OS_WINDOWS
- int fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY, S_IREAD|S_IWRITE);
-#else
- int fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY,
- S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
-#endif
- if (fd == -1) {
- if (errno == EACCES) {
- /* File already exists and we aren't allowed to create a new one
- with the same name */
-#ifdef OS_WINDOWS
- fd = open(filename, O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE);
-#else
- fd = open(filename, O_WRONLY|O_TRUNC,
- S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
-#endif
- }
- if (fd == -1) {
- oscap_seterr(OSCAP_EFAMILY_GLIBC,
- "%s '%s'", strerror(errno), filename);
- return -1;
- }
- }
+ int fd = oscap_open_writable(filename);
+ if (fd == -1)
+ return -1;
buff = xmlOutputBufferCreateFd(fd, NULL);
if (buff == NULL) {
diff --git a/src/common/util.c b/src/common/util.c
index 8f9f751e2..8ca2ad130 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -25,12 +25,14 @@
#include <config.h>
#endif
+#include <fcntl.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#include <stdarg.h>
#include <math.h>
#include <pcre.h>
+#include <sys/stat.h>
#include "util.h"
#include "_error.h"
@@ -482,3 +484,32 @@ char *oscap_windows_error_message(unsigned long error_code)
return error_message;
}
#endif
+
+int oscap_open_writable(const char *filename)
+{
+#ifdef OS_WINDOWS
+ int fd = open(filename, O_WRONLY|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE);
+#else
+ int fd = open(filename, O_WRONLY|O_CREAT|O_TRUNC,
+ S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
+#endif
+ if (fd == -1) {
+ if (errno == EACCES) {
+ /* File already exists and we aren't allowed to create a new one
+ with the same name */
+#ifdef OS_WINDOWS
+ fd = open(filename, O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE);
+#else
+ fd = open(filename, O_WRONLY|O_TRUNC,
+ S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
+#endif
+ }
+ if (fd == -1) {
+ oscap_seterr(OSCAP_EFAMILY_OSCAP,
+ "Could not open output file '%s': %s",
+ filename, strerror(errno));
+ return -1;
+ }
+ }
+ return fd;
+}
diff --git a/src/common/util.h b/src/common/util.h
index c48d92a52..5712f2f0b 100644
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -524,4 +524,16 @@ wchar_t *oscap_windows_str_to_wstr(const char *str);
char *oscap_windows_error_message(unsigned long error_code);
#endif
-#endif /* OSCAP_UTIL_H_ */
+/**
+ * Open a file for writing.
+ * The main difference from fopen() is that if the file exists but its opening
+ * for writing fails as permission denied, it will attempt to open it again
+ * without the O_CREAT flag. This is useful when writing to world-writeable
+ * directories with sticky bit such as /tmp on systems with fs.protected_regular
+ * turned on.
+ * @param filename name of the file to be opened
+ * @return file descriptor or -1 on error
+ */
+int oscap_open_writable(const char *filename);
+
+#endif /* OSCAP_UTIL_H_ */
diff --git a/src/source/xslt.c b/src/source/xslt.c
index 799d5170d..906bfabdb 100644
--- a/src/source/xslt.c
+++ b/src/source/xslt.c
@@ -22,7 +22,6 @@
#include <config.h>
#endif
-#include <fcntl.h>
#include <libxml/parser.h>
#include <libxslt/xslt.h>
#include <libxslt/xsltInternals.h>
@@ -30,7 +29,6 @@
#include <libxslt/xsltutils.h>
#include <libexslt/exslt.h>
#include <string.h>
-#include <sys/stat.h>
#ifdef OS_WINDOWS
#include <io.h>
@@ -91,29 +89,10 @@ static inline int save_stylesheet_result_to_file(xmlDoc *resulting_doc, xsltStyl
int fd = STDOUT_FILENO;
#endif
if (outfile) {
-#ifdef OS_WINDOWS
- fd = open(outfile, O_WRONLY|O_CREAT|O_TRUNC, S_IREAD|S_IWRITE);
-#else
- fd = open(outfile, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
-#endif
- if (fd == -1) {
- if (errno == EACCES) {
- /* File already exists and we aren't allowed to create a new one
- with the same name */
-#ifdef OS_WINDOWS
- fd = open(outfile, O_WRONLY|O_TRUNC, S_IREAD|S_IWRITE);
-#else
- fd = open(outfile, O_WRONLY|O_TRUNC, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH);
-#endif
- }
- if (fd == -1) {
- oscap_seterr(OSCAP_EFAMILY_OSCAP,
- "Could not open output file '%s': %s",
- outfile, strerror(errno));
- return -1;
- }
- }
+ fd = oscap_open_writable(outfile);
}
+ if (fd == -1)
+ return -1;
int ret = xsltSaveResultToFd(fd, resulting_doc, stylesheet);
if (ret < 0) {
diff --git a/tests/API/XCCDF/unittests/CMakeLists.txt b/tests/API/XCCDF/unittests/CMakeLists.txt
index 97e1ab09f..a1c7da67f 100644
--- a/tests/API/XCCDF/unittests/CMakeLists.txt
+++ b/tests/API/XCCDF/unittests/CMakeLists.txt
@@ -2,6 +2,8 @@ add_oscap_test_executable(test_oscap_common
"test_oscap_common.c"
${CMAKE_SOURCE_DIR}/src/common/util.c
${CMAKE_SOURCE_DIR}/src/common/list.c
+ ${CMAKE_SOURCE_DIR}/src/common/error.c
+ ${CMAKE_SOURCE_DIR}/src/common/err_queue.c
)
add_oscap_test_executable(test_xccdf_overrides
diff --git a/tests/API/XCCDF/unittests/test_oscap_common.c b/tests/API/XCCDF/unittests/test_oscap_common.c
index 26ff51d48..939ba8750 100644
--- a/tests/API/XCCDF/unittests/test_oscap_common.c
+++ b/tests/API/XCCDF/unittests/test_oscap_common.c
@@ -28,6 +28,7 @@
#include <string.h>
#include "common/list.h"
#include "common/util.h"
+#include "common/_error.h"
#include "oscap_assert.h"
#define SEEN_LEN 9