| Message ID | 20240517164541.17733-1-andrea.mayer@uniroma2.it (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5447f9708d9e4c17a647b16a9cb29e9e02820bd9 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] ipv6: sr: fix missing sk_buff release in seg6_input_core | expand |
On Fri, May 17, 2024 at 06:45:41PM +0200, 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> Reviewed-by: Simon Horman <horms@kernel.org>
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>
* The message subject would have been a bit nicer with the key word “PATCH”.
* How do you think about to append parentheses to the function name?
…
> The proposed patch addresses the identified memory leak by …
Will a corresponding imperative wording be more desirable for
an improved change description?
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?h=v6.9#n94
Regards,
Markus
Hello: This patch was applied to netdev/net.git (main) by David S. Miller <davem@davemloft.net>: On Fri, 17 May 2024 18:45:41 +0200 you 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. > > [...] Here is the summary with links: - [net] ipv6: sr: fix missing sk_buff release in seg6_input_core https://git.kernel.org/netdev/net/c/5447f9708d9e You are awesome, thank you!
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c index 03b877ff4558..a75df2ec8db0 100644 --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -459,10 +459,8 @@ static int seg6_input_core(struct net *net, struct sock *sk, 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); @@ -486,7 +484,7 @@ static int seg6_input_core(struct net *net, struct sock *sk, err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) - return err; + goto drop; if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, @@ -494,6 +492,9 @@ static int seg6_input_core(struct net *net, struct sock *sk, skb_dst(skb)->dev, seg6_input_finish); return seg6_input_finish(dev_net(skb->dev), NULL, skb); +drop: + kfree_skb(skb); + return err; } static int seg6_input_nf(struct sk_buff *skb)
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(-)