diff options
Diffstat (limited to 'target/linux/generic/patches-4.4/099-0003-net-qmi_wwan-should-hold-RTNL-while-changing-netdev-.patch')
| -rw-r--r-- | target/linux/generic/patches-4.4/099-0003-net-qmi_wwan-should-hold-RTNL-while-changing-netdev-.patch | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.4/099-0003-net-qmi_wwan-should-hold-RTNL-while-changing-netdev-.patch b/target/linux/generic/patches-4.4/099-0003-net-qmi_wwan-should-hold-RTNL-while-changing-netdev-.patch new file mode 100644 index 0000000000..48f7141efb --- /dev/null +++ b/target/linux/generic/patches-4.4/099-0003-net-qmi_wwan-should-hold-RTNL-while-changing-netdev-.patch @@ -0,0 +1,107 @@ +From 6c730080e663b1d629f8aa89348291fbcdc46cd9 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no> +Date: Sun, 6 Dec 2015 21:25:50 +0100 +Subject: [PATCH] net: qmi_wwan: should hold RTNL while changing netdev type +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +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> +--- + drivers/net/usb/qmi_wwan.c | 22 +++++++++++++++------- + 1 file 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); +-- +2.7.4 + |