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* [PATCH 1/1] net: ipv4: fix return value check in esp_remove_trailer()
@ 2023-07-17 14:49 Yuanjun Gong
  2023-07-18 14:44 ` David Ahern
  0 siblings, 1 reply; 5+ messages in thread
From: Yuanjun Gong @ 2023-07-17 14:49 UTC (permalink / raw)
  To: Yuanjun Gong, Steffen Klassert, Herbert Xu, David Ahern, netdev

return an error number if an unexpected result is returned by
pskb_tirm() in esp_remove_trailer().

Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
---
 net/ipv4/esp4.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index ba06ed42e428..0660bf2bdbae 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -732,7 +732,10 @@ static inline int esp_remove_trailer(struct sk_buff *skb)
 		skb->csum = csum_block_sub(skb->csum, csumdiff,
 					   skb->len - trimlen);
 	}
-	pskb_trim(skb, skb->len - trimlen);
+	if (pskb_trim(skb, skb->len - trimlen)) {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	ret = nexthdr[1];
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/1] net: ipv4: fix return value check in esp_remove_trailer()
  2023-07-17 14:49 [PATCH 1/1] net: ipv4: fix return value check in esp_remove_trailer() Yuanjun Gong
@ 2023-07-18 14:44 ` David Ahern
  2023-07-25  6:40   ` [PATCH v2 " Yuanjun Gong
  0 siblings, 1 reply; 5+ messages in thread
From: David Ahern @ 2023-07-18 14:44 UTC (permalink / raw)
  To: Yuanjun Gong, Steffen Klassert, Herbert Xu, netdev

On 7/17/23 8:49 AM, Yuanjun Gong wrote:
> return an error number if an unexpected result is returned by
> pskb_tirm() in esp_remove_trailer().
> 
> Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
> ---
>  net/ipv4/esp4.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
> index ba06ed42e428..0660bf2bdbae 100644
> --- a/net/ipv4/esp4.c
> +++ b/net/ipv4/esp4.c
> @@ -732,7 +732,10 @@ static inline int esp_remove_trailer(struct sk_buff *skb)
>  		skb->csum = csum_block_sub(skb->csum, csumdiff,
>  					   skb->len - trimlen);
>  	}
> -	pskb_trim(skb, skb->len - trimlen);
> +	if (pskb_trim(skb, skb->len - trimlen)) {
> +		ret = -EINVAL;

pskb_trim returns the error from ___pskb_trim; use it instead of
changing it here.


> +		goto out;
> +	}
>  
>  	ret = nexthdr[1];
>  


^ permalink raw reply	[flat|nested] 5+ messages in thread

* [PATCH v2 1/1] net: ipv4: fix return value check in esp_remove_trailer()
  2023-07-18 14:44 ` David Ahern
@ 2023-07-25  6:40   ` Yuanjun Gong
  2023-07-25 17:44     ` Alexander H Duyck
  0 siblings, 1 reply; 5+ messages in thread
From: Yuanjun Gong @ 2023-07-25  6:40 UTC (permalink / raw)
  To: dsahern; +Cc: herbert, netdev, ruc_gongyuanjun, steffen.klassert

return an error number if an unexpected result is returned by
pskb_tirm() in esp_remove_trailer().

Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
---
 net/ipv4/esp4.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index ba06ed42e428..b435e3fe4dc6 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -732,7 +732,9 @@ static inline int esp_remove_trailer(struct sk_buff *skb)
 		skb->csum = csum_block_sub(skb->csum, csumdiff,
 					   skb->len - trimlen);
 	}
-	pskb_trim(skb, skb->len - trimlen);
+	ret = pskb_trim(skb, skb->len - trimlen);
+	if (ret)
+		goto out;
 
 	ret = nexthdr[1];
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH v2 1/1] net: ipv4: fix return value check in esp_remove_trailer()
  2023-07-25  6:40   ` [PATCH v2 " Yuanjun Gong
@ 2023-07-25 17:44     ` Alexander H Duyck
  2023-07-28 10:00       ` Herbert Xu
  0 siblings, 1 reply; 5+ messages in thread
From: Alexander H Duyck @ 2023-07-25 17:44 UTC (permalink / raw)
  To: Yuanjun Gong, dsahern; +Cc: herbert, netdev, steffen.klassert

On Tue, 2023-07-25 at 14:40 +0800, Yuanjun Gong wrote:
> return an error number if an unexpected result is returned by
> pskb_tirm() in esp_remove_trailer().
> 
> Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
> ---
>  net/ipv4/esp4.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
> index ba06ed42e428..b435e3fe4dc6 100644
> --- a/net/ipv4/esp4.c
> +++ b/net/ipv4/esp4.c
> @@ -732,7 +732,9 @@ static inline int esp_remove_trailer(struct sk_buff *skb)
>  		skb->csum = csum_block_sub(skb->csum, csumdiff,
>  					   skb->len - trimlen);
>  	}
> -	pskb_trim(skb, skb->len - trimlen);
> +	ret = pskb_trim(skb, skb->len - trimlen);
> +	if (ret)
> +		goto out;
>  
>  	ret = nexthdr[1];
>  

In what case would you encounter this error? From what I can tell it
looks like there are checks in the callers, specifically the call to
pskb_may_pull() at the start of esp_input() that will go through and
automatically eliminate all the potential reasons for this to fail. So
I am not sure what the point is in adding exception handling for an
exception that is already handled.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH v2 1/1] net: ipv4: fix return value check in esp_remove_trailer()
  2023-07-25 17:44     ` Alexander H Duyck
@ 2023-07-28 10:00       ` Herbert Xu
  0 siblings, 0 replies; 5+ messages in thread
From: Herbert Xu @ 2023-07-28 10:00 UTC (permalink / raw)
  To: Alexander H Duyck; +Cc: Yuanjun Gong, dsahern, netdev, steffen.klassert

On Tue, Jul 25, 2023 at 10:44:50AM -0700, Alexander H Duyck wrote:
> On Tue, 2023-07-25 at 14:40 +0800, Yuanjun Gong wrote:
> > return an error number if an unexpected result is returned by
> > pskb_tirm() in esp_remove_trailer().
> > 
> > Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@163.com>
> > ---
> >  net/ipv4/esp4.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
> > index ba06ed42e428..b435e3fe4dc6 100644
> > --- a/net/ipv4/esp4.c
> > +++ b/net/ipv4/esp4.c
> > @@ -732,7 +732,9 @@ static inline int esp_remove_trailer(struct sk_buff *skb)
> >  		skb->csum = csum_block_sub(skb->csum, csumdiff,
> >  					   skb->len - trimlen);
> >  	}
> > -	pskb_trim(skb, skb->len - trimlen);
> > +	ret = pskb_trim(skb, skb->len - trimlen);
> > +	if (ret)
> > +		goto out;
> >  
> >  	ret = nexthdr[1];
> >  
> 
> In what case would you encounter this error? From what I can tell it
> looks like there are checks in the callers, specifically the call to
> pskb_may_pull() at the start of esp_input() that will go through and
> automatically eliminate all the potential reasons for this to fail. So
> I am not sure what the point is in adding exception handling for an
> exception that is already handled.

Good point.  pskb_trim should never fail at this point because
we've already made the packet completely writeable.

Perhaps we could add a comment?

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2023-07-28 10:00 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-07-17 14:49 [PATCH 1/1] net: ipv4: fix return value check in esp_remove_trailer() Yuanjun Gong
2023-07-18 14:44 ` David Ahern
2023-07-25  6:40   ` [PATCH v2 " Yuanjun Gong
2023-07-25 17:44     ` Alexander H Duyck
2023-07-28 10:00       ` Herbert Xu

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