From: Jiri Bohac Date: Thu, 29 Oct 2009 05:23:54 +0000 (-0700) Subject: bonding: fix a race condition in calls to slave MII ioctls X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d9d5283228d0c752f199c901fff6e1405dc91bcb;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git bonding: fix a race condition in calls to slave MII ioctls In mii monitor mode, bond_check_dev_link() calls the the ioctl handler of slave devices. It stores the ndo_do_ioctl function pointer to a static (!) ioctl variable and later uses it to call the handler with the IOCTL macro. If another thread executes bond_check_dev_link() at the same time (even with a different bond, which none of the locks prevent), a race condition occurs. If the two racing slaves have different drivers, this may result in one driver's ioctl handler being called with a pointer to a net_device controlled with a different driver, resulting in unpredictable breakage. Unless I am overlooking something, the "static" must be a copy'n'paste error (?). Signed-off-by: Jiri Bohac Signed-off-by: David S. Miller --- diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 3f05267b2cfd..40fb5eefc72e 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -691,7 +691,7 @@ static int bond_check_dev_link(struct bonding *bond, struct net_device *slave_dev, int reporting) { const struct net_device_ops *slave_ops = slave_dev->netdev_ops; - static int (*ioctl)(struct net_device *, struct ifreq *, int); + int (*ioctl)(struct net_device *, struct ifreq *, int); struct ifreq ifr; struct mii_ioctl_data *mii;