Commit 2efe5c8f authored by Andrea Mayer's avatar Andrea Mayer Committed by Dong Chenchen
Browse files

ipv6: sr: fix missing sk_buff release in seg6_input_core 

mainline inclusion
from mainline-v6.10-rc1
commit 5447f9708d9e4c17a647b16a9cb29e9e02820bd9
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAC3N2
CVE: CVE-2024-39490

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5447f9708d9e4c17a647b16a9cb29e9e02820bd9



--------------------------------

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 af3b5158 ("ipv6: sr: fix BUG due
to headroom too small after SRH push") and persists even after commit
7a3f5b0d ("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: af3b5158 ("ipv6: sr: fix BUG due to headroom too small after SRH push")
Signed-off-by: default avatarAndrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Conflicts:
	net/ipv6/seg6_iptunnel.c
[commit 7a3f5b0d add seg6_input_core() to seg6_input() for netfilter
hooks of SRv6, which lead to context conflicts]
Signed-off-by: default avatarDong Chenchen <dongchenchen2@huawei.com>
parent 98dea376

net/ipv6/seg6_iptunnel.c

+6 −5
Original line number Diff line number Diff line
@@ -318,10 +318,8 @@ static int seg6_input(struct sk_buff *skb) 
	int err;



	err = seg6_do_srh(skb);

	if (unlikely(err)) {

		kfree_skb(skb);

		return err;

	}

	if (unlikely(err))

		goto drop;



	slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate);
@@ -346,9 +344,12 @@ static int seg6_input(struct sk_buff *skb) 


	err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev));

	if (unlikely(err))

		return err;

		goto drop;



	return dst_input(skb);

drop:

	kfree_skb(skb);

	return err;

}



static int seg6_output(struct net *net, struct sock *sk, struct sk_buff *skb)