drivers/net/niu.c: possible array overflows

drivers/net/niu.c: possible array overflows

[Adrian Bunk]

The Coverity checker spotted the following in drivers/net/niu.c:

<--  snip  -->

...
static int __devinit niu_pci_probe_sprom(struct niu *np)
{
...
        val = nr64(ESPC_MOD_STR_LEN);
        niudbg(PROBE, "SPROM: MOD_STR_LEN[%llu]\n",
               (unsigned long long) val);
        if (val > 8 * 4)
                return -EINVAL;

        for (i = 0; i < val; i += 4) {
                u64 tmp = nr64(ESPC_NCR(5 + (i / 4)));

                np->vpd.model[i + 3] = (tmp >>  0) & 0xff;
                np->vpd.model[i + 2] = (tmp >>  8) & 0xff;
                np->vpd.model[i + 1] = (tmp >> 16) & 0xff;
                np->vpd.model[i + 0] = (tmp >> 24) & 0xff;
        }
        np->vpd.model[val] = '\0';

        val = nr64(ESPC_BD_MOD_STR_LEN);
        niudbg(PROBE, "SPROM: BD_MOD_STR_LEN[%llu]\n",
               (unsigned long long) val);
        if (val > 4 * 4)
                return -EINVAL;

        for (i = 0; i < val; i += 4) {
                u64 tmp = nr64(ESPC_NCR(14 + (i / 4)));

                np->vpd.board_model[i + 3] = (tmp >>  0) & 0xff;
                np->vpd.board_model[i + 2] = (tmp >>  8) & 0xff;
                np->vpd.board_model[i + 1] = (tmp >> 16) & 0xff;
                np->vpd.board_model[i + 0] = (tmp >> 24) & 0xff;
        }
        np->vpd.board_model[val] = '\0';
...

<--  snip  -->

Check where the '\0's get written if "val" has the maximum non-EINVAL 
value.

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: drivers/net/niu.c: possible array overflows

[David Miller]

From: Adrian Bunk <bunk@kernel.org>
Date: Sun, 14 Oct 2007 19:50:24 +0200

> The Coverity checker spotted the following in drivers/net/niu.c:

Thanks for the report Adrian, I'll fix it like this:

commit 503211a947ab13fb44d920f78f1e19057efc277f
Author: David S. Miller <davem@sunset.davemloft.net>
Date:   Mon Oct 15 01:36:24 2007 -0700

    [NIU]: Fix write past end of array in niu_pci_probe_sprom().
    
    Noticed by Coverity checker and reported by Adrian Bunk.
    
    Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/niu.c b/drivers/net/niu.c
index 43bfe7e..54166bd 100644
--- a/drivers/net/niu.c
+++ b/drivers/net/niu.c
@@ -6213,7 +6213,7 @@ static int __devinit niu_pci_probe_sprom(struct niu *np)
 	val = nr64(ESPC_MOD_STR_LEN);
 	niudbg(PROBE, "SPROM: MOD_STR_LEN[%llu]\n",
 	       (unsigned long long) val);
-	if (val > 8 * 4)
+	if (val >= 8 * 4)
 		return -EINVAL;
 
 	for (i = 0; i < val; i += 4) {
@@ -6229,7 +6229,7 @@ static int __devinit niu_pci_probe_sprom(struct niu *np)
 	val = nr64(ESPC_BD_MOD_STR_LEN);
 	niudbg(PROBE, "SPROM: BD_MOD_STR_LEN[%llu]\n",
 	       (unsigned long long) val);
-	if (val > 4 * 4)
+	if (val >= 4 * 4)
 		return -EINVAL;
 
 	for (i = 0; i < val; i += 4) {