3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@xxxxxxx> [ Upstream commit 4f4178f3bb1f470d7fb863ec531e08e20a0fd51c ] Fixes this warning introduced by commit 5b8f15f78e6f ("net: cdc_mbim: handle IPv6 Neigbor Solicitations"): =============================== [ INFO: suspicious RCU usage. ] 3.15.0-rc3 #213 Tainted: G W O ------------------------------- net/8021q/vlan_core.c:69 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 1 no locks held by ksoftirqd/0/3. stack backtrace: CPU: 0 PID: 3 Comm: ksoftirqd/0 Tainted: G W O 3.15.0-rc3 #213 Hardware name: LENOVO 2776LEG/2776LEG, BIOS 6EET55WW (3.15 ) 12/19/2011 0000000000000001 ffff880232533bf0 ffffffff813a5ee6 0000000000000006 ffff880232530090 ffff880232533c20 ffffffff81076b94 0000000000000081 0000000000000000 ffff8802085ac000 ffff88007fc8ea00 ffff880232533c50 Call Trace: [<ffffffff813a5ee6>] dump_stack+0x4e/0x68 [<ffffffff81076b94>] lockdep_rcu_suspicious+0xfa/0x103 [<ffffffff813978a6>] __vlan_find_dev_deep+0x54/0x94 [<ffffffffa04a1938>] cdc_mbim_rx_fixup+0x379/0x66a [cdc_mbim] [<ffffffff813ab76f>] ? _raw_spin_unlock_irqrestore+0x3a/0x49 [<ffffffff81079671>] ? trace_hardirqs_on_caller+0x192/0x1a1 [<ffffffffa059bd10>] usbnet_bh+0x59/0x287 [usbnet] [<ffffffff8104067d>] tasklet_action+0xbb/0xcd [<ffffffff81040057>] __do_softirq+0x14c/0x30d [<ffffffff81040237>] run_ksoftirqd+0x1f/0x50 [<ffffffff8105f13e>] smpboot_thread_fn+0x172/0x18e [<ffffffff8105efcc>] ? SyS_setgroups+0xdf/0xdf [<ffffffff810594b0>] kthread+0xb5/0xbd [<ffffffff813a84b1>] ? __wait_for_common+0x13b/0x170 [<ffffffff810593fb>] ? __kthread_parkme+0x5c/0x5c [<ffffffff813b147c>] ret_from_fork+0x7c/0xb0 [<ffffffff810593fb>] ? __kthread_parkme+0x5c/0x5c Fixes: 5b8f15f78e6f ("net: cdc_mbim: handle IPv6 Neigbor Solicitations") Signed-off-by: Bj�ork <bjorn@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/usb/cdc_mbim.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) --- a/drivers/net/usb/cdc_mbim.c +++ b/drivers/net/usb/cdc_mbim.c @@ -204,17 +204,23 @@ static void do_neigh_solicit(struct usbn return; /* need to send the NA on the VLAN dev, if any */ - if (tci) + rcu_read_lock(); + if (tci) { netdev = __vlan_find_dev_deep(dev->net, htons(ETH_P_8021Q), tci); - else + if (!netdev) { + rcu_read_unlock(); + return; + } + } else { netdev = dev->net; - if (!netdev) - return; + } + dev_hold(netdev); + rcu_read_unlock(); in6_dev = in6_dev_get(netdev); if (!in6_dev) - return; + goto out; is_router = !!in6_dev->cnf.forwarding; in6_dev_put(in6_dev); @@ -224,6 +230,8 @@ static void do_neigh_solicit(struct usbn true /* solicited */, false /* override */, true /* inc_opt */); +out: + dev_put(netdev); } static bool is_neigh_solicit(u8 *buf, size_t len) -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html