]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
tuntap: synchronize through tfiles array instead of tun->numqueues
authorJason Wang <jasowang@redhat.com>
Thu, 9 May 2019 03:20:18 +0000 (23:20 -0400)
committerDavid S. Miller <davem@davemloft.net>
Thu, 9 May 2019 16:21:42 +0000 (09:21 -0700)
commit9871a9e47a2646fe30ae7fd2e67668a8d30912f6
tree06772218a11b4c05b06d31ed92c649cac61b6a8b
parenta35d310f03a692bf4798eb309a1950a06a150620
tuntap: synchronize through tfiles array instead of tun->numqueues

When a queue(tfile) is detached through __tun_detach(), we move the
last enabled tfile to the position where detached one sit but don't
NULL out last position. We expect to synchronize the datapath through
tun->numqueues. Unfortunately, this won't work since we're lacking
sufficient mechanism to order or synchronize the access to
tun->numqueues.

To fix this, NULL out the last position during detaching and check
RCU protected tfile against NULL instead of checking tun->numqueues in
datapath.

Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: weiyongjun (A) <weiyongjun1@huawei.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: c8d68e6be1c3b ("tuntap: multiqueue support")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/tun.c