Re: [PATCH 1/1] When timestamping is enabled, stmmac_tx_clean willcall stmmac_get_tx_hwtstamp to get tx TS. It's possible that skb is NULLbecause there are other network frames that use several descriptors. So wemust return immediately in stmmac_get_tx_hwtstamp if skb is NULL to avoidsystem crash.
From: Daniel Borkmann
Date: Sun Jan 12 2014 - 06:38:46 EST
On 01/12/2014 10:39 AM, Bruce Liu wrote:
When timestamping is enabled, stmmac_tx_clean will call stmmac_get_tx_hwtstamp to get tx TS.
It's possible that skb is NULL because there are other network frames that use several descriptors.
So we must return immediately in stmmac_get_tx_hwtstamp if skb is NULL to avoid system crash.
Signed-off-by: Bruce Liu <damuzi000@xxxxxxxxx>
Please see Documentation/SubmittingPatches +489
You subject line is way too long and should just be something like:
[PATCH net-next] net: stmmac: fix NULL pointer dereference in stmmac_get_tx_hwtstamp
Don't indent your actual commit message with whitespaces as prefix,
and do a line break after around 70 chars.
Btw, I mentioned net-next in the subject since merge window will
open soon anyway.
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 797b56a..47f2287 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -332,7 +332,7 @@ static void stmmac_get_tx_hwtstamp(struct stmmac_priv *priv,
return;
/* exit if skb doesn't support hw tstamp */
- if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)))
+ if (likely(!skb || !(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)))
return;
if (priv->adv_ts)
--
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