[PATCH 5.15.y] fou: remove warn in gue_gro_receive on unsupported protocol

[PATCH 5.15.y] fou: remove warn in gue_gro_receive on unsupported protocol

[libo.chen.cn]

From: Willem de Bruijn <willemb@google.com>

[ Upstream commit dd89a81d850fa9a65f67b4527c0e420d15bf836c ]

Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is
not known or does not have a GRO handler.

Such a packet is easily constructed. Syzbot generates them and sets
off this warning.

Remove the warning as it is expected and not actionable.

The warning was previously reduced from WARN_ON to WARN_ON_ONCE in
commit 270136613bf7 ("fou: Do WARN_ON_ONCE in gue_gro_receive for bad
proto callbacks").

Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240614122552.1649044-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Libo Chen <libo.chen.cn@windriver.com>
---
 net/ipv4/fou.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index 1d67df4d8ed6..b1a8e4eec3f6 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -453,7 +453,7 @@ static struct sk_buff *gue_gro_receive(struct sock *sk,
 
 	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 	ops = rcu_dereference(offloads[proto]);
-	if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
+	if (!ops || !ops->callbacks.gro_receive)
 		goto out;
 
 	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
-- 
2.25.1

Re: [PATCH 5.15.y] fou: remove warn in gue_gro_receive on unsupported protocol

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: dd89a81d850fa9a65f67b4527c0e420d15bf836c

WARNING: Author mismatch between patch and upstream commit:
Backport author: libo.chen.cn@windriver.com
Commit author: Willem de Bruijn <willemb@google.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: 3db4395332e7)
6.1.y | Present (different SHA1: 5a2e37bc648a)
5.15.y | Not found

Note: The patch differs from the upstream commit:
---
1:  dd89a81d850fa ! 1:  9e6170db49f05 fou: remove warn in gue_gro_receive on unsupported protocol
    @@ Metadata
      ## Commit message ##
         fou: remove warn in gue_gro_receive on unsupported protocol
     
    +    [ Upstream commit dd89a81d850fa9a65f67b4527c0e420d15bf836c ]
    +
         Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is
         not known or does not have a GRO handler.
     
    @@ Commit message
         Reviewed-by: Eric Dumazet <edumazet@google.com>
         Link: https://lore.kernel.org/r/20240614122552.1649044-1-willemdebruijn.kernel@gmail.com
         Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    +    Signed-off-by: Libo Chen <libo.chen.cn@windriver.com>
     
    - ## net/ipv4/fou_core.c ##
    -@@ net/ipv4/fou_core.c: static struct sk_buff *gue_gro_receive(struct sock *sk,
    + ## net/ipv4/fou.c ##
    +@@ net/ipv4/fou.c: static struct sk_buff *gue_gro_receive(struct sock *sk,
      
      	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
      	ops = rcu_dereference(offloads[proto]);
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |

Re: [PATCH 5.15.y] fou: remove warn in gue_gro_receive on unsupported protocol

[Greg KH]

On Tue, Dec 10, 2024 at 02:25:50PM +0800, libo.chen.cn@windriver.com wrote:
> From: Willem de Bruijn <willemb@google.com>
> 
> [ Upstream commit dd89a81d850fa9a65f67b4527c0e420d15bf836c ]

Please cc: all relevant people on backports

[PATCH 5.15.y] fou: remove warn in gue_gro_receive on unsupported protocol

[libo.chen.cn]

From: Willem de Bruijn <willemb@google.com>

[ Upstream commit dd89a81d850fa9a65f67b4527c0e420d15bf836c ]

Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is
not known or does not have a GRO handler.

Such a packet is easily constructed. Syzbot generates them and sets
off this warning.

Remove the warning as it is expected and not actionable.

The warning was previously reduced from WARN_ON to WARN_ON_ONCE in
commit 270136613bf7 ("fou: Do WARN_ON_ONCE in gue_gro_receive for bad
proto callbacks").

Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240614122552.1649044-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Libo Chen <libo.chen.cn@windriver.com>
---
 net/ipv4/fou.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/fou.c b/net/ipv4/fou.c
index 1d67df4d8ed6..b1a8e4eec3f6 100644
--- a/net/ipv4/fou.c
+++ b/net/ipv4/fou.c
@@ -453,7 +453,7 @@ static struct sk_buff *gue_gro_receive(struct sock *sk,
 
 	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
 	ops = rcu_dereference(offloads[proto]);
-	if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
+	if (!ops || !ops->callbacks.gro_receive)
 		goto out;
 
 	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
-- 
2.25.1

Re: [PATCH 5.15.y] fou: remove warn in gue_gro_receive on unsupported protocol

[Sasha Levin]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: dd89a81d850fa9a65f67b4527c0e420d15bf836c

WARNING: Author mismatch between patch and upstream commit:
Backport author: libo.chen.cn@eng.windriver.com
Commit author: Willem de Bruijn <willemb@google.com>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.6.y | Present (different SHA1: 3db4395332e7)
6.1.y | Present (different SHA1: 5a2e37bc648a)
5.15.y | Not found

Note: The patch differs from the upstream commit:
---
1:  dd89a81d850fa ! 1:  2115d8ab02118 fou: remove warn in gue_gro_receive on unsupported protocol
    @@ Metadata
      ## Commit message ##
         fou: remove warn in gue_gro_receive on unsupported protocol
     
    +    [ Upstream commit dd89a81d850fa9a65f67b4527c0e420d15bf836c ]
    +
         Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is
         not known or does not have a GRO handler.
     
    @@ Commit message
         Reviewed-by: Eric Dumazet <edumazet@google.com>
         Link: https://lore.kernel.org/r/20240614122552.1649044-1-willemdebruijn.kernel@gmail.com
         Signed-off-by: Jakub Kicinski <kuba@kernel.org>
    +    Signed-off-by: Libo Chen <libo.chen.cn@windriver.com>
     
    - ## net/ipv4/fou_core.c ##
    -@@ net/ipv4/fou_core.c: static struct sk_buff *gue_gro_receive(struct sock *sk,
    + ## net/ipv4/fou.c ##
    +@@ net/ipv4/fou.c: static struct sk_buff *gue_gro_receive(struct sock *sk,
      
      	offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
      	ops = rcu_dereference(offloads[proto]);
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-5.15.y       |  Success    |  Success   |