diff options
| author | Bjørn Mork <bjorn@mork.no> | 2015-12-06 21:25:50 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-12-06 22:27:35 -0500 |
| commit | 6c730080e663b1d629f8aa89348291fbcdc46cd9 (patch) | |
| tree | 90a5cf927ada728cf12e4100ec58afdc2cd49b9b /drivers/net/usb | |
| parent | 6633d3815c099a0aaf28e4853f7a8994331b8c05 (diff) | |
| download | linux-6c730080e663b1d629f8aa89348291fbcdc46cd9.tar.bz2 | |
net: qmi_wwan: should hold RTNL while changing netdev type
The notifier calls were thrown in as a last-minute fix for an
imagined "this device could be part of a bridge" problem. That
revealed a certain lack of locking. Not to mention testing...
Avoid this splat:
RTNL: assertion failed at net/core/dev.c (1639)
CPU: 0 PID: 4293 Comm: bash Not tainted 4.4.0-rc3+ #358
Hardware name: LENOVO 2776LEG/2776LEG, BIOS 6EET55WW (3.15 ) 12/19/2011
0000000000000000 ffff8800ad253d60 ffffffff8122f7cf ffff8800ad253d98
ffff8800ad253d88 ffffffff813833ab 0000000000000002 ffff880230f48560
ffff880230a12900 ffff8800ad253da0 ffffffff813833da 0000000000000002
Call Trace:
[<ffffffff8122f7cf>] dump_stack+0x4b/0x63
[<ffffffff813833ab>] call_netdevice_notifiers_info+0x3d/0x59
[<ffffffff813833da>] call_netdevice_notifiers+0x13/0x15
[<ffffffffa09be227>] raw_ip_store+0x81/0x193 [qmi_wwan]
[<ffffffff8131e149>] dev_attr_store+0x20/0x22
[<ffffffff811d858b>] sysfs_kf_write+0x49/0x50
[<ffffffff811d8027>] kernfs_fop_write+0x10a/0x151
[<ffffffff8117249a>] __vfs_write+0x26/0xa5
[<ffffffff81085ed4>] ? percpu_down_read+0x53/0x7f
[<ffffffff81174c9e>] ? __sb_start_write+0x5f/0xb0
[<ffffffff81174c9e>] ? __sb_start_write+0x5f/0xb0
[<ffffffff81172c37>] vfs_write+0xa3/0xe7
[<ffffffff811734ad>] SyS_write+0x50/0x7e
[<ffffffff8145c517>] entry_SYSCALL_64_fastpath+0x12/0x6f
Fixes: 32f7adf633b9 ("net: qmi_wwan: support "raw IP" mode")
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/usb')
| -rw-r--r-- | drivers/net/usb/qmi_wwan.c | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c index 98add3bf8821..babc84a3946c 100644 --- a/drivers/net/usb/qmi_wwan.c +++ b/drivers/net/usb/qmi_wwan.c @@ -16,6 +16,7 @@ #include <linux/etherdevice.h> #include <linux/if_arp.h> #include <linux/mii.h> +#include <linux/rtnetlink.h> #include <linux/usb.h> #include <linux/usb/cdc.h> #include <linux/usb/usbnet.h> @@ -92,7 +93,7 @@ static ssize_t raw_ip_store(struct device *d, struct device_attribute *attr, co struct usbnet *dev = netdev_priv(to_net_dev(d)); struct qmi_wwan_state *info = (void *)&dev->data; bool enable; - int err; + int ret; if (strtobool(buf, &enable)) return -EINVAL; @@ -101,18 +102,22 @@ static ssize_t raw_ip_store(struct device *d, struct device_attribute *attr, co if (enable == (info->flags & QMI_WWAN_FLAG_RAWIP)) return len; + if (!rtnl_trylock()) + return restart_syscall(); + /* we don't want to modify a running netdev */ if (netif_running(dev->net)) { netdev_err(dev->net, "Cannot change a running device\n"); - return -EBUSY; + ret = -EBUSY; + goto err; } /* let other drivers deny the change */ - err = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE, dev->net); - err = notifier_to_errno(err); - if (err) { + ret = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE, dev->net); + ret = notifier_to_errno(ret); + if (ret) { netdev_err(dev->net, "Type change was refused\n"); - return err; + goto err; } if (enable) @@ -121,7 +126,10 @@ static ssize_t raw_ip_store(struct device *d, struct device_attribute *attr, co info->flags &= ~QMI_WWAN_FLAG_RAWIP; qmi_wwan_netdev_setup(dev->net); call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev->net); - return len; + ret = len; +err: + rtnl_unlock(); + return ret; } static DEVICE_ATTR_RW(raw_ip); |