commit d76dfc612b40b6a9de0a3fe57fe1fa3db7a1ae3b
author Seth Forshee <seth.forshee@canonical.com> Mon Feb 14 08:52:25 2011 -0600
committer John W. Linville <linville@tuxdriver.com> Mon Feb 14 15:50:17 2011 -0500
tree 169aca14bd1a3514452aeac5170214280937a6eb
parent a3dc5e881a8a5199bf371fdd4530cfa18280ca83

rt2x00: Check for errors from skb_pad() calls

Commit 739fd94 ("rt2x00: Pad beacon to multiple of 32 bits")
added calls to skb_pad() without checking the return value,
which could cause problems if any of those calls does happen
to fail. Add checks to prevent this from happening.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800lib.c

diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index c9bf074..7a68a67 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -773,13 +773,14 @@
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 	unsigned int beacon_base;
 	unsigned int padding_len;
-	u32 reg;
+	u32 orig_reg, reg;
 
 	/*
 	 * Disable beaconing while we are reloading the beacon data,
 	 * otherwise we might be sending out invalid data.
 	 */
 	rt2800_register_read(rt2x00dev, BCN_TIME_CFG, &reg);
+	orig_reg = reg;
 	rt2x00_set_field32(&reg, BCN_TIME_CFG_BEACON_GEN, 0);
 	rt2800_register_write(rt2x00dev, BCN_TIME_CFG, reg);
 
@@ -810,7 +811,14 @@
 	 * Write entire beacon with TXWI and padding to register.
 	 */
 	padding_len = roundup(entry->skb->len, 4) - entry->skb->len;
-	skb_pad(entry->skb, padding_len);
+	if (padding_len && skb_pad(entry->skb, padding_len)) {
+		ERROR(rt2x00dev, "Failure padding beacon, aborting\n");
+		/* skb freed by skb_pad() on failure */
+		entry->skb = NULL;
+		rt2800_register_write(rt2x00dev, BCN_TIME_CFG, orig_reg);
+		return;
+	}
+
 	beacon_base = HW_BEACON_OFFSET(entry->entry_idx);
 	rt2800_register_multiwrite(rt2x00dev, beacon_base, entry->skb->data,
 				   entry->skb->len + padding_len);