Re: [PATCH] param_sysfs_builtin memchr argument fix

[WANG Cong]

On Mon, Oct 08, 2007 at 02:50:10PM +0800, Dave Young wrote:
>If memchr argument is longer than strlen(kp->name), there will be some
>weird result. 
>
>Signed-off-by: Dave Young <hidave.darkstar@xxxxxxxxx> 
>
>---
>params.c |   10 ++++++++--
>1 file changed, 8 insertions(+), 2 deletions(-)


Hmm, you used diffstat without -p1?


>
>diff -upr linux/kernel/params.c linux.new/kernel/params.c
>--- linux/kernel/params.c	2007-10-08 14:30:06.000000000 +0800
>+++ linux.new/kernel/params.c	2007-10-08 14:31:22.000000000 +0800
>@@ -592,15 +592,21 @@ static void __init param_sysfs_builtin(v
> 
> 	for (i=0; i < __stop___param - __start___param; i++) {
> 		char *dot;
>+		int kplen;
> 
> 		kp = &__start___param[i];
>+		kplen = strlen(kp->name);

strlen() returns a size_t value, which is unsigned. ;)

> 
> 		/* We do not handle args without periods. */
>-		dot = memchr(kp->name, '.', MAX_KBUILD_MODNAME);
>+		if (kplen > MAX_KBUILD_MODNAME) {
>+			DEBUGP("kernel parameter %s is too long\n", kp->name);
>+			continue;
>+		}
>+		dot = memchr(kp->name, '.', kplen);
> 		if (!dot) {
> 			DEBUGP("couldn't find period in %s\n", kp->name);
> 			continue;
>-		}
>+		} 

You add an extra whitespace in the end of the line.


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