netdev - Re: [PATCH net v2 1/4] ipv4: fix source address selection with route leak

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <cc29ed8c-f0b2-4e6d-8347-21bb13d0bbbc@6wind.com>
Date: Mon, 8 Jul 2024 20:13:56 +0200
From: Nicolas Dichtel <nicolas.dichtel@...nd.com>
To: David Ahern <dsahern@...nel.org>, "David S . Miller"
 <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Eric Dumazet <edumazet@...gle.com>
Cc: netdev@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH net v2 1/4] ipv4: fix source address selection with route
 leak

Le 07/07/2024 à 18:58, David Ahern a écrit :
> On 7/5/24 8:52 AM, Nicolas Dichtel wrote:
>> By default, an address assigned to the output interface is selected when
>> the source address is not specified. This is problematic when a route,
>> configured in a vrf, uses an interface from another vrf (aka route leak).
>> The original vrf does not own the selected source address.
>>
>> Let's add a check against the output interface and call the appropriate
>> function to select the source address.
>>
>> CC: stable@...r.kernel.org
>> Fixes: 8cbb512c923d ("net: Add source address lookup op for VRF")
>> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@...nd.com>
>> ---
>>  net/ipv4/fib_semantics.c | 11 +++++++++--
>>  1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
>> index f669da98d11d..459082f4936d 100644
>> --- a/net/ipv4/fib_semantics.c
>> +++ b/net/ipv4/fib_semantics.c
>> @@ -2270,6 +2270,13 @@ void fib_select_path(struct net *net, struct fib_result *res,
>>  		fib_select_default(fl4, res);
>>  
>>  check_saddr:
>> -	if (!fl4->saddr)
>> -		fl4->saddr = fib_result_prefsrc(net, res);
>> +	if (!fl4->saddr) {
>> +		struct net_device *l3mdev = dev_get_by_index_rcu(net, fl4->flowi4_l3mdev);
> 
> long line length. separate setting the value:
> 
> 		struct net_device *l3mdev;
> 
> 		l3mdev = dev_get_by_index_rcu(net, fl4->flowi4_l3mdev);
The checkpatch limit is 100-column.
If the 80-column limit needs to be enforced in net/, maybe a special case should
be added in checkpatch.


Regards,
Nicolas