Re: [PATCH net] Fix net/hsr/hsr_device to check for freed skb buffer.

[Sergei Shtylyov]

Hello!

On 4/20/2017 10:28 AM, Peter Heise wrote:


Fixed an unchecked call of skb_put_padto. Return value was ignored
before, however, skb_put_padto frees skb buffer in case of error.

As reported by Dan Carpenter on kernel-janitors.

Signed-off-by: Peter Heise 
---
 net/hsr/hsr_device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
index c73160fb11e7..22d693f213be 100644
--- a/net/hsr/hsr_device.c
+++ b/net/hsr/hsr_device.c
@@ -314,7 +314,8 @@ static void send_hsr_supervision_frame(struct hsr_port 
*master,
hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(struct hsr_sup_payload));
ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);

-   skb_put_padto(skb, ETH_ZLEN + HSR_HLEN);
+   if(skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))


   Need a space after *if*. Pleae run your patches thru scripts/checkpatch.pl 
before sending.



+   return;

hsr_forward_skb(skb, master);
return;


MBR, Seregi

[PATCH net] Fix net/hsr/hsr_device to check for freed skb buffer.

[Peter Heise]

Fixed an unchecked call of skb_put_padto. Return value was ignored
before, however, skb_put_padto frees skb buffer in case of error.

As reported by Dan Carpenter on kernel-janitors.

Signed-off-by: Peter Heise 
---
 net/hsr/hsr_device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c
index c73160fb11e7..22d693f213be 100644
--- a/net/hsr/hsr_device.c
+++ b/net/hsr/hsr_device.c
@@ -314,7 +314,8 @@ static void send_hsr_supervision_frame(struct hsr_port 
*master,
hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(struct hsr_sup_payload));
ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
 
-   skb_put_padto(skb, ETH_ZLEN + HSR_HLEN);
+   if(skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
+   return;
 
hsr_forward_skb(skb, master);
return;
-- 
2.11.0