From bd07063dd11f6fda903802a5868960be3690d327 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 23 Oct 2023 08:23:41 -0700 Subject: net: don't use input buffer of __dev_alloc_name() as a scratch space Callers of __dev_alloc_name() want to pass dev->name as the output buffer. Make __dev_alloc_name() not clobber that buffer on failure, and remove the workarounds in callers. dev_alloc_name_ns() is now completely unnecessary. The extra strscpy() added here will be gone by the end of the patch series. Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20231023152346.3639749-2-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/core/dev.c | 33 ++++++++------------------------- 1 file changed, 8 insertions(+), 25 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 1025dc79bc49..874c7daa81f5 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1057,7 +1057,7 @@ EXPORT_SYMBOL(dev_valid_name); * __dev_alloc_name - allocate a name for a device * @net: network namespace to allocate the device name in * @name: name format string - * @buf: scratch buffer and result name string + * @res: result name string * * Passed a format string - eg "lt%d" it will try and find a suitable * id. It scans list of devices to build up a free map, then chooses @@ -1068,13 +1068,14 @@ EXPORT_SYMBOL(dev_valid_name); * Returns the number of the unit assigned or a negative errno code. */ -static int __dev_alloc_name(struct net *net, const char *name, char *buf) +static int __dev_alloc_name(struct net *net, const char *name, char *res) { int i = 0; const char *p; const int max_netdevices = 8*PAGE_SIZE; unsigned long *inuse; struct net_device *d; + char buf[IFNAMSIZ]; if (!dev_valid_name(name)) return -EINVAL; @@ -1124,8 +1125,10 @@ static int __dev_alloc_name(struct net *net, const char *name, char *buf) } snprintf(buf, IFNAMSIZ, name, i); - if (!netdev_name_in_use(net, buf)) + if (!netdev_name_in_use(net, buf)) { + strscpy(res, buf, IFNAMSIZ); return i; + } /* It is possible to run out of possible slots * when the name is long and there isn't enough space left @@ -1154,20 +1157,6 @@ static int dev_prep_valid_name(struct net *net, struct net_device *dev, return 0; } -static int dev_alloc_name_ns(struct net *net, - struct net_device *dev, - const char *name) -{ - char buf[IFNAMSIZ]; - int ret; - - BUG_ON(!net); - ret = __dev_alloc_name(net, name, buf); - if (ret >= 0) - strscpy(dev->name, buf, IFNAMSIZ); - return ret; -} - /** * dev_alloc_name - allocate a name for a device * @dev: device @@ -1184,20 +1173,14 @@ static int dev_alloc_name_ns(struct net *net, int dev_alloc_name(struct net_device *dev, const char *name) { - return dev_alloc_name_ns(dev_net(dev), dev, name); + return __dev_alloc_name(dev_net(dev), name, dev->name); } EXPORT_SYMBOL(dev_alloc_name); static int dev_get_valid_name(struct net *net, struct net_device *dev, const char *name) { - char buf[IFNAMSIZ]; - int ret; - - ret = dev_prep_valid_name(net, dev, name, buf); - if (ret >= 0) - strscpy(dev->name, buf, IFNAMSIZ); - return ret; + return dev_prep_valid_name(net, dev, name, dev->name); } /** -- cgit