lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

inet: add RCU protection to inet->opt

Browse Source 
We lack proper synchronization to manipulate inet->opt ip_options

Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.

Another thread can change inet->opt pointer and free old one under us.

Use RCU to protect inet->opt (changed to inet->inet_opt).

Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.

We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2011-04-21 09:45:37 +00:00
committed by David S. Miller
parent 0a14842f5a
commit f6d8bd051c
17 changed files with 241 additions and 168 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
net/ipv6/tcp_ipv6.c
View File

@@ -1469,7 +1469,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
First: no IPv4 options.
*/
newinet->opt = NULL;
newinet->inet_opt = NULL;
newnp->ipv6_fl_list = NULL;
/* Clone RX bits */