4.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 0e1d6eca5113858ed2caea61a5adc03c595f6096 ]
We have an impressive number of syzkaller bugs that are linked to the fact that syzbot was able to create a networking device with millions of TX (or RX) queues.
Let's limit the number of RX/TX queues to 4096, this really should cover all known cases.
A separate patch will add various cond_resched() in the loops handling sysfs entries at device creation and dismantle.
Tested:
lpaa6:~# ip link add gre-4097 numtxqueues 4097 numrxqueues 4097 type ip6gretap RTNETLINK answers: Invalid argument
lpaa6:~# time ip link add gre-4096 numtxqueues 4096 numrxqueues 4096 type ip6gretap
real 0m0.180s user 0m0.000s sys 0m0.107s
Fixes: 76ff5cc91935 ("rtnl: allow to specify number of rx and tx queues on device creation") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/core/rtnetlink.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2116,6 +2116,12 @@ struct net_device *rtnl_create_link(stru else if (ops->get_num_rx_queues) num_rx_queues = ops->get_num_rx_queues();
+ if (num_tx_queues < 1 || num_tx_queues > 4096) + return ERR_PTR(-EINVAL); + + if (num_rx_queues < 1 || num_rx_queues > 4096) + return ERR_PTR(-EINVAL); + err = -ENOMEM; dev = alloc_netdev_mqs(ops->priv_size, ifname, name_assign_type, ops->setup, num_tx_queues, num_rx_queues);