diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-04-21 09:45:37 +0000 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2013-06-10 11:43:31 +0200 |
| commit | b8710128e201bc0d628d9644454585925a6e59fd (patch) | |
| tree | c52c86fc99f70c902f927811d494b681604a67e5 /fs/splice.c | |
| parent | 66096e8915ce1ff5daa23362dc890651b160be7d (diff) | |
inet: add RCU protection to inet->opt
commit f6d8bd051c391c1c0458a30b2a7abcd939329259 upstream.
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>
[dannf/bwh: backported to Debian's 2.6.32]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'fs/splice.c')
0 files changed, 0 insertions, 0 deletions