diff options
| author | Alexei Starovoitov <ast@plumgrid.com> | 2015-10-07 20:55:41 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-10-11 14:40:05 +0300 |
| commit | ff936a04e5f28b7e0455be0e7fa91334f89e4b44 (patch) | |
| tree | f23b1f44945600ce2631560eb1f93364606b62b6 /net/packet | |
| parent | d49ae37c613f7cc1f4c1fd6ef073d60c32e000dd (diff) | |
| download | linux-ff936a04e5f28b7e0455be0e7fa91334f89e4b44.tar.xz | |
bpf: fix cb access in socket filter programs
eBPF socket filter programs may see junk in 'u32 cb[5]' area,
since it could have been used by protocol layers earlier.
For socket filter programs used in af_packet we need to clean
20 bytes of skb->cb area if it could be used by the program.
For programs attached to TCP/UDP sockets we need to save/restore
these 20 bytes, since it's used by protocol layers.
Remove SK_RUN_FILTER macro, since it's no longer used.
Long term we may move this bpf cb area to per-cpu scratch, but that
requires addition of new 'per-cpu load/store' instructions,
so not suitable as a short term fix.
Fixes: d691f9e8d440 ("bpf: allow programs to write to certain skb fields")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/packet')
| -rw-r--r-- | net/packet/af_packet.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 81c900fbc4a4..104910f7d1fb 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1423,7 +1423,7 @@ static unsigned int fanout_demux_bpf(struct packet_fanout *f, rcu_read_lock(); prog = rcu_dereference(f->bpf_prog); if (prog) - ret = BPF_PROG_RUN(prog, skb) % num; + ret = bpf_prog_run_clear_cb(prog, skb) % num; rcu_read_unlock(); return ret; @@ -1939,16 +1939,16 @@ out_free: return err; } -static unsigned int run_filter(const struct sk_buff *skb, - const struct sock *sk, - unsigned int res) +static unsigned int run_filter(struct sk_buff *skb, + const struct sock *sk, + unsigned int res) { struct sk_filter *filter; rcu_read_lock(); filter = rcu_dereference(sk->sk_filter); if (filter != NULL) - res = SK_RUN_FILTER(filter, skb); + res = bpf_prog_run_clear_cb(filter->prog, skb); rcu_read_unlock(); return res; |