Commit 35edfdc7 authored Jan 26, 2019 by Josh Elsasser Committed by David S. Miller Jan 29, 2019

net: set default network namespace in init_dummy_netdev()



Assign a default net namespace to netdevs created by init_dummy_netdev().
Fixes a NULL pointer dereference caused by busy-polling a socket bound to
an iwlwifi wireless device, which bumps the per-net BUSYPOLLRXPACKETS stat
if napi_poll() received packets:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000190
  IP: napi_busy_loop+0xd6/0x200
  Call Trace:
    sock_poll+0x5e/0x80
    do_sys_poll+0x324/0x5a0
    SyS_poll+0x6c/0xf0
    do_syscall_64+0x6b/0x1f0
    entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: 7db6b048 ("net: Commonize busy polling code to focus on napi_id instead of socket")
Signed-off-by: Josh Elsasser <jelsasser@appneta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 0f0ed828

net/core/dev.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -8712,6 +8712,9 @@ int init_dummy_netdev(struct net_device *dev)
		set_bit(__LINK_STATE_PRESENT, &dev->state);
		set_bit(__LINK_STATE_START, &dev->state);

		/* napi_busy_loop stats accounting wants this */
		dev_net_set(dev, &init_net);

		/* Note : We dont allocate pcpu_refcnt for dummy devices,
		* because users of this 'device' dont need to change
		* its refcount.

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