From 4f4178f3bb1f470d7fb863ec531e08e20a0fd51c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= Date: Sat, 3 May 2014 16:12:47 +0200 Subject: net: cdc_mbim: __vlan_find_dev_deep need rcu_read_lock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: [] dump_stack+0x4e/0x68 [] lockdep_rcu_suspicious+0xfa/0x103 [] __vlan_find_dev_deep+0x54/0x94 [] cdc_mbim_rx_fixup+0x379/0x66a [cdc_mbim] [] ? _raw_spin_unlock_irqrestore+0x3a/0x49 [] ? trace_hardirqs_on_caller+0x192/0x1a1 [] usbnet_bh+0x59/0x287 [usbnet] [] tasklet_action+0xbb/0xcd [] __do_softirq+0x14c/0x30d [] run_ksoftirqd+0x1f/0x50 [] smpboot_thread_fn+0x172/0x18e [] ? SyS_setgroups+0xdf/0xdf [] kthread+0xb5/0xbd [] ? __wait_for_common+0x13b/0x170 [] ? __kthread_parkme+0x5c/0x5c [] ret_from_fork+0x7c/0xb0 [] ? __kthread_parkme+0x5c/0x5c Fixes: 5b8f15f78e6f ("net: cdc_mbim: handle IPv6 Neigbor Solicitations") Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller --- drivers/net/usb/cdc_mbim.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) (limited to 'drivers/net/usb') diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c index c9f3281506af..13f7705fd679 100644 --- a/drivers/net/usb/cdc_mbim.c +++ b/drivers/net/usb/cdc_mbim.c @@ -204,17 +204,23 @@ static void do_neigh_solicit(struct usbnet *dev, u8 *buf, u16 tci) 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 usbnet *dev, u8 *buf, u16 tci) true /* solicited */, false /* override */, true /* inc_opt */); +out: + dev_put(netdev); } static bool is_neigh_solicit(u8 *buf, size_t len) -- cgit v1.2.3