kernel/sys.c: avoid argv_free(NULL)

If argv_split() failed, the code will end up calling argv_free(NULL). Fix it up and clean things up a bit. Addresses Coverity report 703573. Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Kees Cook <keescook@chromium.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Alan Cox <alan@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/sys.c: avoid argv_free(NULL)
If argv_split() failed, the code will end up calling argv_free(NULL). Fix it up and clean things up a bit. Addresses Coverity report 703573. Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Kees Cook <keescook@chromium.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: WANG Cong <xiyou.wangcong@gmail.com> Cc: Alan Cox <alan@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Morton · Linus Torvalds
1 parent 45226e944c
Showing 1 changed file with 25 additions and 19 deletions Side-by-side Diff
kernel/sys.c
@@ -2186,46 +2186,52 @@
 	argv_free(info->argv);
 }
  
-/**
- * orderly_poweroff - Trigger an orderly system poweroff
- * @force: force poweroff if command execution fails
- *
- * This may be called from any context to trigger a system shutdown.
- * If the orderly shutdown fails, it will force an immediate shutdown.
- */
-int orderly_poweroff(bool force)
+static int __orderly_poweroff(void)
 {
 	int argc;
-	char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
+	char **argv;
 	static char *envp[] = {
 		"HOME=/",
 		"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
 		NULL
 	};
-	int ret = -ENOMEM;
+	int ret;
  
+	argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
 	if (argv == NULL) {
 		printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
 		       __func__, poweroff_cmd);
-		goto out;
+		return -ENOMEM;
 	}
  
 	ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_NO_WAIT,
 				      NULL, argv_cleanup, NULL);
-out:
-	if (likely(!ret))
-		return 0;
-
 	if (ret == -ENOMEM)
 		argv_free(argv);
  
-	if (force) {
+	return ret;
+}
+
+/**
+ * orderly_poweroff - Trigger an orderly system poweroff
+ * @force: force poweroff if command execution fails
+ *
+ * This may be called from any context to trigger a system shutdown.
+ * If the orderly shutdown fails, it will force an immediate shutdown.
+ */
+int orderly_poweroff(bool force)
+{
+	int ret = __orderly_poweroff();
+
+	if (ret && force) {
 		printk(KERN_WARNING "Failed to start orderly shutdown: "
 		       "forcing the issue\n");
  
-		/* I guess this should try to kick off some daemon to
-		   sync and poweroff asap.  Or not even bother syncing
-		   if we're doing an emergency shutdown? */
+		/*
+		 * I guess this should try to kick off some daemon to sync and
+		 * poweroff asap.  Or not even bother syncing if we're doing an
+		 * emergency shutdown?
+		 */
 		emergency_sync();
 		kernel_power_off();
 	}
...	...	@@ -2186,46 +2186,52 @@
2186	2186	argv_free(info->argv);
2187	2187	}
2188	2188
2189		-/**
2190		- * orderly_poweroff - Trigger an orderly system poweroff
2191		- * @force: force poweroff if command execution fails
2192		- *
2193		- * This may be called from any context to trigger a system shutdown.
2194		- * If the orderly shutdown fails, it will force an immediate shutdown.
2195		- */
2196		-int orderly_poweroff(bool force)
	2189	+static int __orderly_poweroff(void)
2197	2190	{
2198	2191	int argc;
2199		- char **argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
	2192	+ char **argv;
2200	2193	static char *envp[] = {
2201	2194	"HOME=/",
2202	2195	"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
2203	2196	NULL
2204	2197	};
2205		- int ret = -ENOMEM;
	2198	+ int ret;
2206	2199
	2200	+ argv = argv_split(GFP_ATOMIC, poweroff_cmd, &argc);
2207	2201	if (argv == NULL) {
2208	2202	printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n",
2209	2203	__func__, poweroff_cmd);
2210		- goto out;
	2204	+ return -ENOMEM;
2211	2205	}
2212	2206
2213	2207	ret = call_usermodehelper_fns(argv[0], argv, envp, UMH_NO_WAIT,
2214	2208	NULL, argv_cleanup, NULL);
2215		-out:
2216		- if (likely(!ret))
2217		- return 0;
2218		-
2219	2209	if (ret == -ENOMEM)
2220	2210	argv_free(argv);
2221	2211
2222		- if (force) {
	2212	+ return ret;
	2213	+}
	2214	+
	2215	+/**
	2216	+ * orderly_poweroff - Trigger an orderly system poweroff
	2217	+ * @force: force poweroff if command execution fails
	2218	+ *
	2219	+ * This may be called from any context to trigger a system shutdown.
	2220	+ * If the orderly shutdown fails, it will force an immediate shutdown.
	2221	+ */
	2222	+int orderly_poweroff(bool force)
	2223	+{
	2224	+ int ret = __orderly_poweroff();
	2225	+
	2226	+ if (ret && force) {
2223	2227	printk(KERN_WARNING "Failed to start orderly shutdown: "
2224	2228	"forcing the issue\n");
2225	2229
2226		- /* I guess this should try to kick off some daemon to
2227		- sync and poweroff asap. Or not even bother syncing
2228		- if we're doing an emergency shutdown? */
	2230	+ /*
	2231	+ * I guess this should try to kick off some daemon to sync and
	2232	+ * poweroff asap. Or not even bother syncing if we're doing an
	2233	+ * emergency shutdown?
	2234	+ */
2229	2235	emergency_sync();
2230	2236	kernel_power_off();
2231	2237	}