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| author | Xin Long <lucien.xin@gmail.com> | 2017-11-19 14:31:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-17 17:07:58 +0300 |
| commit | 29d631e5941366ee5eb50b3b592ca99186115a63 (patch) | |
| tree | 938103a4f850f7e4ad4f157351c0bedf937d1c59 /drivers/net/tun.c | |
| parent | 7afe2e668ee2b1f465dcccb942da9d8f8d873f20 (diff) | |
| download | linux-29d631e5941366ee5eb50b3b592ca99186115a63.tar.xz | |
tun: fix rcu_read_lock imbalance in tun_build_skb
[ Upstream commit 654d573845f35017dc397840fa03610fef3d08b0 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/tun.c')
| -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 a5c47db94846..d06f88312e1e 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1326,6 +1326,7 @@ 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; @@ -1358,7 +1359,7 @@ 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; } |