Subject: [PATCH 2.6.25][resend] rndis_host: fix oops when query for OID_GEN_PHYSICAL_MEDIUM fails

From: Jussi Kivilinna <[email-masked]>
Date: Sun, 23 Mar 2008 12:45:44 +0200

From: Jussi Kivilinna <[email-masked]>

When query for OID_GEN_PHYSICAL_MEDIUM fails, uninitialized pointer
'phym' is being accessed in generic_rndis_bind(), resulting OOPS.
Patch fixes phym to be initialized and setup correctly when
rndis_query() for physical medium fails.

Bug was introduced by following commit:
commit 039ee17d1baabaa21783a0d5ab3e8c6d8c794bdf
Author: Jussi Kivilinna <[email-masked]>
Date:   Sun Jan 27 23:34:33 2008 +0200

Reported-by: Dmitri Monakhov <[email-masked]>
Signed-off-by: Jussi Kivilinna <[email-masked]>
Acked-by: David Brownell <[email-masked]>
---

 drivers/net/usb/rndis_host.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/usb/rndis_host.c b/drivers/net/usb/rndis_host.c
index a613247..1b810ab 100644
--- a/drivers/net/usb/rndis_host.c
+++ b/drivers/net/usb/rndis_host.c
@@ -287,7 +287,7 @@ generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
 		struct rndis_set_c	*set_c;
 		struct rndis_halt	*halt;
 	} u;
-	u32			tmp, *phym;
+	u32			tmp, phym_unspec, *phym;
 	int			reply_len;
 	unsigned char		*bp;
 
@@ -359,12 +359,15 @@ generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
 		goto halt_fail_and_release;
 
 	/* Check physical medium */
+	phym = NULL;
 	reply_len = sizeof *phym;
 	retval = rndis_query(dev, intf, u.buf, OID_GEN_PHYSICAL_MEDIUM,
 			0, (void **) &phym, &reply_len);
-	if (retval != 0)
+	if (retval != 0 || !phym) {
 		/* OID is optional so don't fail here. */
-		*phym = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
+		phym_unspec = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
+		phym = &phym_unspec;
+	}
 	if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
 			*phym != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
 		if (netif_msg_probe(dev))