Patchwork [U-Boot] printenv show garbage on out-of-memory conditions

login
register
mail settings
Submitter Maxime Larocque
Date Sept. 28, 2012, 3 p.m.
Message ID <5065BB7D.3010806@yahoo.ca>
Download mbox | patch
Permalink /patch/188194/
State Accepted
Delegated to: Joe Hershberger
Headers show

Comments

Maxime Larocque - Sept. 28, 2012, 3 p.m.
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

Signed-off-by: Maxime Larocque <maxmtl2002@yahoo.ca>
Tom Rini - April 17, 2013, 3:36 p.m.
On Fri, Sep 28, 2012 at 05:00:13AM -0000, Maxime Larocque wrote:

> 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!

Patch

--- common/cmd_nvedit.c
+++ common/cmd_nvedit.c
@@ -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;