diff mbox

powerpc:beyond ARRAY_SIZE of args.args

Message ID 4A15AF33.60100@gmail.com (mailing list archive)
State Rejected, archived
Headers show

Commit Message

roel kluin May 21, 2009, 7:44 p.m. UTC 
Do not go beyond ARRAY_SIZE of args.args

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
I'm quite sure the first is correct, but should maybe `args.nret'
and `nargs + args.nret' also be `>= ARRAY_SIZE(args.args)'?

Comments

Paul Mackerras May 21, 2009, 11:10 p.m. UTC | #1 
Roel Kluin writes:

> Do not go beyond ARRAY_SIZE of args.args
> 
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
> ---
> I'm quite sure the first is correct, but should maybe `args.nret'
> and `nargs + args.nret' also be `>= ARRAY_SIZE(args.args)'?

I don't think this change is needed, and it changes a user-visible
API, so I'm nacking it unless you can convince me there's really a
problem.

If nargs == ARRAY_SIZE(args.args), then args.nret must be zero, so
nothing will access *(args.rets).

Paul.
diff mbox

Patch

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 1f8505c..c94ab76 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -779,7 +779,7 @@  asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
 		return -EFAULT;
 
 	nargs = args.nargs;
-	if (nargs > ARRAY_SIZE(args.args)
+	if (nargs >= ARRAY_SIZE(args.args)
 	    || args.nret > ARRAY_SIZE(args.args)
 	    || nargs + args.nret > ARRAY_SIZE(args.args))
 		return -EINVAL;