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printenv show garbage on out-of-memory conditions

PATCH In review Maxime Larocque 2 participants 2 messages Sep 28, 2012 – Apr 17, 2013

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PATCH 1/1 printenv show garbage on out-of-memory conditions

Hello,

In common/cmd_nvedit.c, en env_print(), the wrong type is used for len. hexport_r() returns -1 on error (like OOM), which is converted to 0xffffffff when put in an unsigned. Said value is obviously bigger then 0, and as a result an uninitialized string is then displayed. Other usages of hexport_r() in the code correctly uses ssize_t to keep its return value.

Does not seem to be critical, but it is misleading when debugging a OOM error...

I have added a printf to display something in case of error; I'll leave it to the committer to keep it or remove it.

Found in U-Boot 2011.12, but still present in current git.

Maxime Larocque

cmd_nvedit.c +4 -1
@@ -110,7 +110,7 @@
  static int env_print(char *name)
  {
  	char *res = NULL;
-	size_t len;
+	ssize_t len;
  
  	if (name) {		/* print a single name */
  		ENTRY e, *ep;
@@ -132,6 +132,9 @@
  		free(res);
  		return len;
  	}
+	else {
+		printf("## Error: cannot export environment\n");
+	}
  
  	/* should never happen */
  	return 0;
#1 lore raw
Quoted 8 lines · Maxime Larocque

Hello,

In common/cmd_nvedit.c, en env_print(), the wrong type is used for len. hexport_r() returns -1 on error (like OOM), which is converted to 0xffffffff when put in an unsigned. Said value is obviously bigger then 0, and as a result an uninitialized string is then displayed. Other usages of hexport_r() in the code correctly uses ssize_t to keep its return value.

Applied to u-boot/master, with some minor fixups for application. Thanks!

Signature · 8 lines
Tom
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