Re: Missing skb_pad() return value checks in rt2x00 driver
From: Ivo Van Doorn <hidden>
Date: 2011-02-14 16:38:42
Hi,
From 0de24c34fc6f59d1d557a3cb16adcc32414d4c46 Mon Sep 17 00:00:00 2001
From: Seth Forshee <redacted>
Date: Mon, 14 Feb 2011 08:52:25 -0600
Subject: [PATCH] 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 <redacted>Acked-by: Ivo van Doorn <redacted>
quoted hunk ↗ jump to hunk
--- drivers/net/wireless/rt2x00/rt2800lib.c | 12 ++++++++++-- drivers/net/wireless/rt2x00/rt61pci.c | 12 ++++++++++-- drivers/net/wireless/rt2x00/rt73usb.c | 12 ++++++++++-- 3 files changed, 30 insertions(+), 6 deletions(-)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 @@ void rt2800_write_beacon(struct queue_entry *entry, struct txentry_desc *txdesc)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, ®); + orig_reg = reg; rt2x00_set_field32(®, BCN_TIME_CFG_BEACON_GEN, 0); rt2800_register_write(rt2x00dev, BCN_TIME_CFG, reg);@@ -810,7 +811,14 @@ void rt2800_write_beacon(struct queue_entry *entry, struct txentry_desc *txdesc)* 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);diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c index dd2164d..927a4a3 100644 --- a/drivers/net/wireless/rt2x00/rt61pci.c +++ b/drivers/net/wireless/rt2x00/rt61pci.c@@ -1978,13 +1978,14 @@ static void rt61pci_write_beacon(struct queue_entry *entry,struct queue_entry_priv_pci *entry_priv = entry->priv_data; 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. */ rt2x00pci_register_read(rt2x00dev, TXRX_CSR9, ®); + orig_reg = reg; rt2x00_set_field32(®, TXRX_CSR9_BEACON_GEN, 0); rt2x00pci_register_write(rt2x00dev, TXRX_CSR9, reg);@@ -2002,7 +2003,14 @@ static void rt61pci_write_beacon(struct queue_entry *entry,* Write entire beacon with descriptor 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; + rt2x00pci_register_write(rt2x00dev, TXRX_CSR9, orig_reg); + return; + } + beacon_base = HW_BEACON_OFFSET(entry->entry_idx); rt2x00pci_register_multiwrite(rt2x00dev, beacon_base, entry_priv->desc, TXINFO_SIZE);diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c index 5ff72de..6e9981a 100644 --- a/drivers/net/wireless/rt2x00/rt73usb.c +++ b/drivers/net/wireless/rt2x00/rt73usb.c@@ -1533,13 +1533,14 @@ static void rt73usb_write_beacon(struct queue_entry *entry,struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev; 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. */ rt2x00usb_register_read(rt2x00dev, TXRX_CSR9, ®); + orig_reg = reg; rt2x00_set_field32(®, TXRX_CSR9_BEACON_GEN, 0); rt2x00usb_register_write(rt2x00dev, TXRX_CSR9, reg);@@ -1563,7 +1564,14 @@ static void rt73usb_write_beacon(struct queue_entry *entry,* Write entire beacon with descriptor 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; + rt2x00usb_register_write(rt2x00dev, TXRX_CSR9, orig_reg); + return; + } + beacon_base = HW_BEACON_OFFSET(entry->entry_idx); rt2x00usb_register_multiwrite(rt2x00dev, beacon_base, entry->skb->data, entry->skb->len + padding_len); -- 1.7.1