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Message-ID: <5516f2af-cc92-408a-89ce-f571bcc998d6@kernel.org>
Date: Fri, 17 May 2024 16:04:14 -0600
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Subject: Re: [net] ipv6: sr: fix missing sk_buff release in seg6_input_core
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To: Andrea Mayer <andrea.mayer@uniroma2.it>,
 "David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>,
 Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
 David Lebrun <david.lebrun@uclouvain.be>, netdev@vger.kernel.org,
 linux-kernel@vger.kernel.org
Cc: Stefano Salsano <stefano.salsano@uniroma2.it>,
 Paolo Lungaroni <paolo.lungaroni@uniroma2.it>,
 Ahmed Abdelsalam <ahabdels.dev@gmail.com>
References: <20240517164541.17733-1-andrea.mayer@uniroma2.it>
From: David Ahern <dsahern@kernel.org>
In-Reply-To: <20240517164541.17733-1-andrea.mayer@uniroma2.it>
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On 5/17/24 10:45 AM, Andrea Mayer wrote:
> The seg6_input() function is responsible for adding the SRH into a
> packet, delegating the operation to the seg6_input_core(). This function
> uses the skb_cow_head() to ensure that there is sufficient headroom in
> the sk_buff for accommodating the link-layer header.
> In the event that the skb_cow_header() function fails, the
> seg6_input_core() catches the error but it does not release the sk_buff,
> which will result in a memory leak.
> 
> This issue was introduced in commit af3b5158b89d ("ipv6: sr: fix BUG due
> to headroom too small after SRH push") and persists even after commit
> 7a3f5b0de364 ("netfilter: add netfilter hooks to SRv6 data plane"),
> where the entire seg6_input() code was refactored to deal with netfilter
> hooks.
> 
> The proposed patch addresses the identified memory leak by requiring the
> seg6_input_core() function to release the sk_buff in the event that
> skb_cow_head() fails.
> 
> Fixes: af3b5158b89d ("ipv6: sr: fix BUG due to headroom too small after SRH push")
> Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
> ---
>  net/ipv6/seg6_iptunnel.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 

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