From a48e5fafecfb9c0c807d7e7284b5ff884dfb7a3a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 2 Jul 2014 02:25:15 -0700 Subject: [PATCH] vlan: free percpu stats in device destructor Madalin-Cristian reported crashs happening after a recent commit (5a4ae5f6e7d4 "vlan: unnecessary to check if vlan_pcpu_stats is NULL") ----------------------------------------------------------------------- root@p5040ds:~# vconfig add eth8 1 root@p5040ds:~# vconfig rem eth8.1 Unable to handle kernel paging request for data at address 0x2bc88028 Faulting instruction address: 0xc058e950 Oops: Kernel access of bad area, sig: 11 [#1] SMP NR_CPUS=8 CoreNet Generic Modules linked in: CPU: 3 PID: 2167 Comm: vconfig Tainted: G W 3.16.0-rc3-00346-g65e85bf #2 task: e7264d90 ti: e2c2c000 task.ti: e2c2c000 NIP: c058e950 LR: c058ea30 CTR: c058e900 REGS: e2c2db20 TRAP: 0300 Tainted: G W (3.16.0-rc3-00346-g65e85bf) MSR: 00029002 CR: 48000428 XER: 20000000 DEAR: 2bc88028 ESR: 00000000 GPR00: c047299c e2c2dbd0 e7264d90 00000000 2bc88000 00000000 ffffffff 00000000 GPR08: 0000000f 00000000 000000ff 00000000 28000422 10121928 10100000 10100000 GPR16: 10100000 00000000 c07c5968 00000000 00000000 00000000 e2c2dc48 e7838000 GPR24: c07c5bac c07c58a8 e77290cc c07b0000 00000000 c05de6c0 e7838000 e2c2dc48 NIP [c058e950] vlan_dev_get_stats64+0x50/0x170 LR [c058ea30] vlan_dev_get_stats64+0x130/0x170 Call Trace: [e2c2dbd0] [ffffffea] 0xffffffea (unreliable) [e2c2dc20] [c047299c] dev_get_stats+0x4c/0x140 [e2c2dc40] [c0488ca8] rtnl_fill_ifinfo+0x3d8/0x960 [e2c2dd70] [c0489f4c] rtmsg_ifinfo+0x6c/0x110 [e2c2dd90] [c04731d4] rollback_registered_many+0x344/0x3b0 [e2c2ddd0] [c047332c] rollback_registered+0x2c/0x50 [e2c2ddf0] [c0476058] unregister_netdevice_queue+0x78/0xf0 [e2c2de00] [c058d800] unregister_vlan_dev+0xc0/0x160 [e2c2de20] [c058e360] vlan_ioctl_handler+0x1c0/0x550 [e2c2de90] [c045d11c] sock_ioctl+0x28c/0x2f0 [e2c2deb0] [c010d070] do_vfs_ioctl+0x90/0x7b0 [e2c2df20] [c010d7d0] SyS_ioctl+0x40/0x80 [e2c2df40] [c000f924] ret_from_syscall+0x0/0x3c Fix this problem by freeing percpu stats from dev->destructor() instead of ndo_uninit() Reported-by: Madalin-Cristian Bucur Signed-off-by: Eric Dumazet Tested-by: Madalin-Cristian Bucur Fixes: 5a4ae5f6e7d4 ("vlan: unnecessary to check if vlan_pcpu_stats is NULL") Cc: Li RongQing Signed-off-by: David S. Miller --- net/8021q/vlan_dev.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index ad2ac3c00398..dd11f612e03e 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -627,8 +627,6 @@ static void vlan_dev_uninit(struct net_device *dev) struct vlan_dev_priv *vlan = vlan_dev_priv(dev); int i; - free_percpu(vlan->vlan_pcpu_stats); - vlan->vlan_pcpu_stats = NULL; for (i = 0; i < ARRAY_SIZE(vlan->egress_priority_map); i++) { while ((pm = vlan->egress_priority_map[i]) != NULL) { vlan->egress_priority_map[i] = pm->next; @@ -785,6 +783,15 @@ static const struct net_device_ops vlan_netdev_ops = { .ndo_get_lock_subclass = vlan_dev_get_lock_subclass, }; +static void vlan_dev_free(struct net_device *dev) +{ + struct vlan_dev_priv *vlan = vlan_dev_priv(dev); + + free_percpu(vlan->vlan_pcpu_stats); + vlan->vlan_pcpu_stats = NULL; + free_netdev(dev); +} + void vlan_setup(struct net_device *dev) { ether_setup(dev); @@ -794,7 +801,7 @@ void vlan_setup(struct net_device *dev) dev->tx_queue_len = 0; dev->netdev_ops = &vlan_netdev_ops; - dev->destructor = free_netdev; + dev->destructor = vlan_dev_free; dev->ethtool_ops = &vlan_ethtool_ops; memset(dev->broadcast, 0, ETH_ALEN); -- 2.20.1