iMX/i2som-imx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

packet: read num_members once in packet_rcv_fanout()

Browse Source 
[ Upstream commit f98f4514d0 ]

We need to tell compiler it must not read f->num_members multiple
times. Otherwise testing if num is not zero is flaky, and we could
attempt an invalid divide by 0 in fanout_demux_cpu()

Note bug was present in packet_rcv_fanout_hash() and
packet_rcv_fanout_lb() but final 3.1 had a simple location
after commit 95ec3eb417 ("packet: Add 'cpu' fanout policy.")

Fixes: dc99f60069 ("packet: Add fanout support.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This commit is contained in:
Eric Dumazet
2015-06-16 07:59:11 -07:00
committed by Ben Hutchings
parent 41431e402f
commit f5a27902fd
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
net/packet/af_packet.c
View File

@ -1211,7 +1211,7 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
struct packet_fanout *f = pt->af_packet_priv;
unsigned int num = f->num_members;
unsigned int num = ACCESS_ONCE(f->num_members);
struct packet_sock *po;
struct sock *sk;