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author | Xin Long <lucien.xin@gmail.com> | 2017-11-19 12:31:04 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-11-19 13:22:31 +0100 |
commit | 654d573845f35017dc397840fa03610fef3d08b0 (patch) | |
tree | ca78d6425d2624b845c0b57b34e1f740a5fda841 | |
parent | tcp: when scheduling TLP, time of RTO should account for current ACK (diff) | |
download | linux-654d573845f35017dc397840fa03610fef3d08b0.tar.xz linux-654d573845f35017dc397840fa03610fef3d08b0.zip |
tun: fix rcu_read_lock imbalance in tun_build_skb
rcu_read_lock in tun_build_skb is used to rcu_dereference tun->xdp_prog
safely, rcu_read_unlock should be done in every return path.
Now I could see one place missing it, where it returns NULL in switch-case
XDP_REDIRECT, another palce using rcu_read_lock wrongly, where it returns
NULL in if (xdp_xmit) chunk.
So fix both in this patch.
Fixes: 761876c857cb ("tap: XDP support")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r-- | drivers/net/tun.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 6bb1e604aadd..5a2ea78a008f 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1485,6 +1485,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, err = xdp_do_redirect(tun->dev, &xdp, xdp_prog); if (err) goto err_redirect; + rcu_read_unlock(); return NULL; case XDP_TX: xdp_xmit = true; @@ -1517,7 +1518,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, if (xdp_xmit) { skb->dev = tun->dev; generic_xdp_tx(skb, xdp_prog); - rcu_read_lock(); + rcu_read_unlock(); return NULL; } |