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| author | Jakub Kicinski <kuba@kernel.org> | 2025-01-29 19:15:19 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-02-21 14:01:38 +0100 |
| commit | 5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a (patch) | |
| tree | cf1179993596f555a9c94cadcbb21ebcb67028ce | |
| parent | 4a855c5aec41bf84922224ab7a74e088776e3ac4 (diff) | |
| download | linux-5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a.tar.gz linux-5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a.tar.bz2 linux-5ab11a4e219e93b8b31a27f8ec98d42afadd8b7a.zip | |
net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels
[ Upstream commit 92191dd1073088753821b862b791dcc83e558e07 ]
Some lwtunnels have a dst cache for post-transformation dst.
If the packet destination did not change we may end up recording
a reference to the lwtunnel in its own cache, and the lwtunnel
state will never be freed.
Discovered by the ioam6.sh test, kmemleak was recently fixed
to catch per-cpu memory leaks. I'm not sure if rpl and seg6
can actually hit this, but in principle I don't see why not.
Fixes: 8cb3bf8bff3c ("ipv6: ioam: Add support for the ip6ip6 encapsulation")
Fixes: 6c8702c60b88 ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Fixes: a7a29f9c361f ("net: ipv6: add rpl sr tunnel")
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250130031519.2716843-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/ipv6/ioam6_iptunnel.c | 9 | ||||
| -rw-r--r-- | net/ipv6/rpl_iptunnel.c | 9 | ||||
| -rw-r--r-- | net/ipv6/seg6_iptunnel.c | 9 |
3 files changed, 18 insertions, 9 deletions
diff --git a/net/ipv6/ioam6_iptunnel.c b/net/ipv6/ioam6_iptunnel.c index e81b45b1f655..fb6cb540cd1b 100644 --- a/net/ipv6/ioam6_iptunnel.c +++ b/net/ipv6/ioam6_iptunnel.c @@ -413,9 +413,12 @@ do_encap: goto drop; } - local_bh_disable(); - dst_cache_set_ip6(&ilwt->cache, cache_dst, &fl6.saddr); - local_bh_enable(); + /* cache only if we don't create a dst reference loop */ + if (dst->lwtstate != cache_dst->lwtstate) { + local_bh_disable(); + dst_cache_set_ip6(&ilwt->cache, cache_dst, &fl6.saddr); + local_bh_enable(); + } err = skb_cow_head(skb, LL_RESERVED_SPACE(cache_dst->dev)); if (unlikely(err)) diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c index 7ba22d2f2bfe..be084089ec78 100644 --- a/net/ipv6/rpl_iptunnel.c +++ b/net/ipv6/rpl_iptunnel.c @@ -236,9 +236,12 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb) goto drop; } - local_bh_disable(); - dst_cache_set_ip6(&rlwt->cache, dst, &fl6.saddr); - local_bh_enable(); + /* cache only if we don't create a dst reference loop */ + if (orig_dst->lwtstate != dst->lwtstate) { + local_bh_disable(); + dst_cache_set_ip6(&rlwt->cache, dst, &fl6.saddr); + local_bh_enable(); + } err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c index 4bf937bfc263..316dbc2694f2 100644 --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -575,9 +575,12 @@ static int seg6_output_core(struct net *net, struct sock *sk, goto drop; } - local_bh_disable(); - dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr); - local_bh_enable(); + /* cache only if we don't create a dst reference loop */ + if (orig_dst->lwtstate != dst->lwtstate) { + local_bh_disable(); + dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr); + local_bh_enable(); + } err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) |