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| author | David Ahern <dsahern@gmail.com> | 2018-01-10 13:00:39 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-01-15 13:50:07 -0500 |
| commit | cbbdf8433a5f117b1a2119ea30fc651b61ef7570 (patch) | |
| tree | f8db54b9ab381bbde880ab1d2b869730c48a3eaf /net/netlink | |
| parent | 59b36613e85fb16ebf9feaf914570879cd5c2a21 (diff) | |
| download | lwn-cbbdf8433a5f117b1a2119ea30fc651b61ef7570.tar.gz lwn-cbbdf8433a5f117b1a2119ea30fc651b61ef7570.zip | |
netlink: extack needs to be reset each time through loop
syzbot triggered the WARN_ON in netlink_ack testing the bad_attr value.
The problem is that netlink_rcv_skb loops over the skb repeatedly invoking
the callback and without resetting the extack leaving potentially stale
data. Initializing each time through avoids the WARN_ON.
Fixes: 2d4bc93368f5a ("netlink: extended ACK reporting")
Reported-by: syzbot+315fa6766d0f7c359327@syzkaller.appspotmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink')
| -rw-r--r-- | net/netlink/af_netlink.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 79cc1bf36e4a..47ef2d8683d6 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2384,7 +2384,7 @@ int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, struct nlmsghdr *, struct netlink_ext_ack *)) { - struct netlink_ext_ack extack = {}; + struct netlink_ext_ack extack; struct nlmsghdr *nlh; int err; @@ -2405,6 +2405,7 @@ int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, if (nlh->nlmsg_type < NLMSG_MIN_TYPE) goto ack; + memset(&extack, 0, sizeof(extack)); err = cb(skb, nlh, &extack); if (err == -EINTR) goto skip; |