tg3: fix tigon3_dma_hwbug_workaround()
Ari got kernel panics using tg3 NIC, and bisected to 2669069aacc9 "tg3:
enable transmit time stamping."
This is because tigon3_dma_hwbug_workaround() might alloc a new skb and
free the original. We panic when skb_tx_timestamp() is called on freed
skb.
Reported-by: Ari Savolainen <ari.m.savolainen@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index c11a2b8..d469004 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -6029,12 +6029,12 @@
/* Workaround 4GB and 40-bit hardware DMA bugs. */
static int tigon3_dma_hwbug_workaround(struct tg3_napi *tnapi,
- struct sk_buff *skb,
+ struct sk_buff **pskb,
u32 *entry, u32 *budget,
u32 base_flags, u32 mss, u32 vlan)
{
struct tg3 *tp = tnapi->tp;
- struct sk_buff *new_skb;
+ struct sk_buff *new_skb, *skb = *pskb;
dma_addr_t new_addr = 0;
int ret = 0;
@@ -6076,7 +6076,7 @@
}
dev_kfree_skb(skb);
-
+ *pskb = new_skb;
return ret;
}
@@ -6305,7 +6305,7 @@
*/
entry = tnapi->tx_prod;
budget = tg3_tx_avail(tnapi);
- if (tigon3_dma_hwbug_workaround(tnapi, skb, &entry, &budget,
+ if (tigon3_dma_hwbug_workaround(tnapi, &skb, &entry, &budget,
base_flags, mss, vlan))
goto out_unlock;
}