From 877774af9162dde25e314ff99a427dd28435c26a Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>

Date: Wed, 10 Jun 2015 15:19:03 -0400

Subject: [PATCH] ima-setup: write policy one line at a time

ima_write_policy() expects data to be written as one or more

rules, no more than PAGE_SIZE at a time. Easiest way to ensure

that we are not splitting rules is to read and write one line at

a time.

https://bugzilla.redhat.com/show_bug.cgi?id=1226948

(cherry picked from commit 92994160afa888255a7ede525dd16e3f1e2ed10d)

Cherry-picked from: 9299416

Resolves: #1222517

---

 src/core/ima-setup.c | 41 +++++++++++++++++------------------------

 1 file changed, 17 insertions(+), 24 deletions(-)

diff --git a/src/core/ima-setup.c b/src/core/ima-setup.c

index 1d4acfa3b..81ce2cda9 100644

--- a/src/core/ima-setup.c

+++ b/src/core/ima-setup.c

@@ -24,11 +24,6 @@

 #include <unistd.h>

 #include <stdio.h>

 #include <errno.h>

-#include <sys/types.h>

-#include <sys/stat.h>

-#include <fcntl.h>

-#include <sys/stat.h>

-#include <sys/mman.h>

 #include "ima-setup.h"

 #include "util.h"

@@ -39,20 +34,19 @@

 #define IMA_POLICY_PATH "/etc/ima/ima-policy"

 int ima_setup(void) {

-        int r = 0;

-

 #ifdef HAVE_IMA

-        _cleanup_close_ int policyfd = -1, imafd = -1;

-        struct stat st;

-        char *policy;

+        _cleanup_fclose_ FILE *input = NULL;

+        _cleanup_close_ int imafd = -1;

+        unsigned lineno = 0;

+        char line[page_size()];

         if (access(IMA_SECFS_DIR, F_OK) < 0) {

                 log_debug("IMA support is disabled in the kernel, ignoring.");

                 return 0;

         }

-        policyfd = open(IMA_POLICY_PATH, O_RDONLY|O_CLOEXEC);

-        if (policyfd < 0) {

+        input = fopen(IMA_POLICY_PATH, "re");

+        if (!input) {

                 log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_WARNING, errno,

                                "Failed to open the IMA custom policy file "IMA_POLICY_PATH", ignoring: %m");

                 return 0;

@@ -69,20 +63,19 @@ int ima_setup(void) {

                 return 0;

         }

-        if (fstat(policyfd, &st) < 0)

-                return log_error_errno(errno, "Failed to fstat "IMA_POLICY_PATH": %m");

+        FOREACH_LINE(line, input,

+                     return log_error_errno(errno, "Failed to read the IMA custom policy file "IMA_POLICY_PATH": %m")) {

+                size_t len;

-        policy = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, policyfd, 0);

-        if (policy == MAP_FAILED)

-                return log_error_errno(errno, "Failed to mmap "IMA_POLICY_PATH": %m");

+                len = strlen(line);

+                lineno++;

-        r = loop_write(imafd, policy, (size_t) st.st_size, false);

-        if (r < 0)

-                log_error_errno(r, "Failed to load the IMA custom policy file "IMA_POLICY_PATH": %m");

-        else

-                log_info("Successfully loaded the IMA custom policy "IMA_POLICY_PATH".");

+                if (len > 0 && write(imafd, line, len) < 0)

+                        return log_error_errno(errno, "Failed to load the IMA custom policy file "IMA_POLICY_PATH"%u: %m",

+                                               lineno);

+        }

-        munmap(policy, st.st_size);

+        log_info("Successfully loaded the IMA custom policy "IMA_POLICY_PATH".");

 #endif /* HAVE_IMA */

-        return r;

+        return 0;

 }