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| author | Eric Dumazet <edumazet@google.com> | 2024-08-20 16:08:58 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-08-29 17:36:00 +0200 |
| commit | 56efc253196751ece1fc535a5b582be127b0578a (patch) | |
| tree | c91f24e36a537cadf8bd0222f81e92359e30357f /net | |
| parent | e44bd76dd072756e674f45c5be00153f4ded68b2 (diff) | |
| download | linux-stable-56efc253196751ece1fc535a5b582be127b0578a.tar.gz linux-stable-56efc253196751ece1fc535a5b582be127b0578a.tar.bz2 linux-stable-56efc253196751ece1fc535a5b582be127b0578a.zip | |
ipv6: fix possible UAF in ip6_finish_output2()
[ Upstream commit da273b377ae0d9bd255281ed3c2adb228321687b ]
If skb_expand_head() returns NULL, skb has been freed
and associated dst/idev could also have been freed.
We need to hold rcu_read_lock() to make sure the dst and
associated idev are alive.
Fixes: 5796015fa968 ("ipv6: allocate enough headroom in ip6_finish_output2()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vasily Averin <vasily.averin@linux.dev>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20240820160859.3786976-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/ip6_output.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index d44ddce4c9f4..8778431acffd 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -70,11 +70,15 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * /* Be paranoid, rather than too clever. */ if (unlikely(hh_len > skb_headroom(skb)) && dev->header_ops) { + /* Make sure idev stays alive */ + rcu_read_lock(); skb = skb_expand_head(skb, hh_len); if (!skb) { IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); + rcu_read_unlock(); return -ENOMEM; } + rcu_read_unlock(); } hdr = ipv6_hdr(skb); |