The 'state->im' value will always be non-zero after
the 'while' statement, so the check can be removed.

Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
---
 net/ipv6/mcast.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 714cdc9e2b8e..9696343d0aa9 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -3013,8 +3013,6 @@ static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_s
 				continue;
 			state->im = rcu_dereference(state->idev->mc_list);
 		}
-		if (!state->im)
-			break;
 		psf = rcu_dereference(state->im->mca_sources);
 	}
 out:
-- 
2.39.2

On 8/28/23 5:18 AM, Gavrilov Ilia wrote:
> The 'state->im' value will always be non-zero after
> the 'while' statement, so the check can be removed.
> 
> Found by InfoTeCS on behalf of Linux Verification Center
> (linuxtesting.org) with SVACE.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
> ---
>  net/ipv6/mcast.c | 2 --
>  1 file changed, 2 deletions(-)
> 
> diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
> index 714cdc9e2b8e..9696343d0aa9 100644
> --- a/net/ipv6/mcast.c
> +++ b/net/ipv6/mcast.c
> @@ -3013,8 +3013,6 @@ static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_s
>  				continue;
>  			state->im = rcu_dereference(state->idev->mc_list);
>  		}
> -		if (!state->im)
> -			break;
>  		psf = rcu_dereference(state->im->mca_sources);
>  	}
>  out:

agree the check is not needed, but I also believe it does not need to be
backported. Since net-next is closed, resubmit after 9/11.

--
pw-bot: defer

On 8/29/23 05:44, David Ahern wrote:
> On 8/28/23 5:18 AM, Gavrilov Ilia wrote:
>> The 'state->im' value will always be non-zero after
>> the 'while' statement, so the check can be removed.
>>
>> Found by InfoTeCS on behalf of Linux Verification Center
>> (linuxtesting.org) with SVACE.
>>
>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
>> Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
>> ---
>>   net/ipv6/mcast.c | 2 --
>>   1 file changed, 2 deletions(-)
>>
>> diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
>> index 714cdc9e2b8e..9696343d0aa9 100644
>> --- a/net/ipv6/mcast.c
>> +++ b/net/ipv6/mcast.c
>> @@ -3013,8 +3013,6 @@ static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_s
>>   				continue;
>>   			state->im = rcu_dereference(state->idev->mc_list);
>>   		}
>> -		if (!state->im)
>> -			break;
>>   		psf = rcu_dereference(state->im->mca_sources);
>>   	}
>>   out:
> 
> agree the check is not needed, but I also believe it does not need to be
> backported. Since net-next is closed, resubmit after 9/11.
> 
> --
> pw-bot: defer

I'll resend it after 9/11.
Thank you for the review!