[PATCH v2] net: ipv4: Avoid bounds check warning

[PATCH v2] net: ipv4: Avoid bounds check warning

[zhanggenjian]

From: huhai <huhai@kylinos.cn>

Fix the following build warning when CONFIG_IPV6 is not set:

In function ‘fortify_memcpy_chk’,
    inlined from ‘tcp_md5_do_add’ at net/ipv4/tcp_ipv4.c:1210:2:
./include/linux/fortify-string.h:328:4: error: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
  328 |    __write_overflow_field(p_size_field, size);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: huhai <huhai@kylinos.cn>
---
 net/ipv4/tcp_ipv4.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 457f5b5d5d4a..46ae9d535086 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1208,8 +1208,8 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
 	key->l3index = l3index;
 	key->flags = flags;
 	memcpy(&key->addr, addr,
-	       (family == AF_INET6) ? sizeof(struct in6_addr) :
-				      sizeof(struct in_addr));
+	       (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6) ? sizeof(struct in6_addr) :
+								 sizeof(struct in_addr));
 	hlist_add_head_rcu(&key->node, &md5sig->head);
 	return 0;
 }
-- 
2.27.0

Re: [PATCH v2] net: ipv4: Avoid bounds check warning

[David Ahern]

On 5/26/22 4:12 AM, zhanggenjian wrote:
> From: huhai <huhai@kylinos.cn>
> 
> Fix the following build warning when CONFIG_IPV6 is not set:
> 
> In function ‘fortify_memcpy_chk’,
>     inlined from ‘tcp_md5_do_add’ at net/ipv4/tcp_ipv4.c:1210:2:
> ./include/linux/fortify-string.h:328:4: error: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>   328 |    __write_overflow_field(p_size_field, size);
>       |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Suggested-by: Paolo Abeni <pabeni@redhat.com>
> Signed-off-by: huhai <huhai@kylinos.cn>
> ---
>  net/ipv4/tcp_ipv4.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>

Re: [PATCH v2] net: ipv4: Avoid bounds check warning

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 26 May 2022 18:12:13 +0800 you wrote:
> From: huhai <huhai@kylinos.cn>
> 
> Fix the following build warning when CONFIG_IPV6 is not set:
> 
> In function ‘fortify_memcpy_chk’,
>     inlined from ‘tcp_md5_do_add’ at net/ipv4/tcp_ipv4.c:1210:2:
> ./include/linux/fortify-string.h:328:4: error: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>   328 |    __write_overflow_field(p_size_field, size);
>       |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> [...]

Here is the summary with links:
  - [v2] net: ipv4: Avoid bounds check warning
    https://git.kernel.org/netdev/net/c/3a2cd89bfbeb

You are awesome, thank you!
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