Revision a98fdcef941e107eeabae622d85a1f476f25a160 authored by Oleg Nesterov on 14 January 2008, 21:02:37 UTC, committed by Linus Torvalds on 14 January 2008, 21:23:00 UTC
Commit 84427eaef1fb91704c7112bdb598c810003b99f3 (remove task_ppid_nr_ns) moved the task_tgid_nr_ns(task->real_parent) outside of lock_task_sighand(). This is wrong, ->real_parent could be freed/reused. Both ->parent/real_parent point to nothing after __exit_signal() because we remove the child from ->children list, and thus the child can't be reparented when its parent exits. rcu_read_lock() protects ->parent/real_parent, but _only_ if we know it was valid before we take rcu lock. Revert this part of the patch. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 4fd3670
nl80211.c
/*
* This is the new netlink-based wireless configuration interface.
*
* Copyright 2006, 2007 Johannes Berg <johannes@sipsolutions.net>
*/
#include <linux/if.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/if_ether.h>
#include <linux/ieee80211.h>
#include <linux/nl80211.h>
#include <linux/rtnetlink.h>
#include <linux/netlink.h>
#include <net/genetlink.h>
#include <net/cfg80211.h>
#include "core.h"
#include "nl80211.h"
/* the netlink family */
static struct genl_family nl80211_fam = {
.id = GENL_ID_GENERATE, /* don't bother with a hardcoded ID */
.name = "nl80211", /* have users key off the name instead */
.hdrsize = 0, /* no private header */
.version = 1, /* no particular meaning now */
.maxattr = NL80211_ATTR_MAX,
};
/* internal helper: get drv and dev */
static int get_drv_dev_by_info_ifindex(struct genl_info *info,
struct cfg80211_registered_device **drv,
struct net_device **dev)
{
int ifindex;
if (!info->attrs[NL80211_ATTR_IFINDEX])
return -EINVAL;
ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
*dev = dev_get_by_index(&init_net, ifindex);
if (!*dev)
return -ENODEV;
*drv = cfg80211_get_dev_from_ifindex(ifindex);
if (IS_ERR(*drv)) {
dev_put(*dev);
return PTR_ERR(*drv);
}
return 0;
}
/* policy for the attributes */
static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
[NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
[NL80211_ATTR_WIPHY_NAME] = { .type = NLA_NUL_STRING,
.len = BUS_ID_SIZE-1 },
[NL80211_ATTR_IFTYPE] = { .type = NLA_U32 },
[NL80211_ATTR_IFINDEX] = { .type = NLA_U32 },
[NL80211_ATTR_IFNAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ-1 },
};
/* message building helper */
static inline void *nl80211hdr_put(struct sk_buff *skb, u32 pid, u32 seq,
int flags, u8 cmd)
{
/* since there is no private header just add the generic one */
return genlmsg_put(skb, pid, seq, &nl80211_fam, flags, cmd);
}
/* netlink command implementations */
static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
struct cfg80211_registered_device *dev)
{
void *hdr;
hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_WIPHY);
if (!hdr)
return -1;
NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, dev->idx);
NLA_PUT_STRING(msg, NL80211_ATTR_WIPHY_NAME, wiphy_name(&dev->wiphy));
return genlmsg_end(msg, hdr);
nla_put_failure:
return genlmsg_cancel(msg, hdr);
}
static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
{
int idx = 0;
int start = cb->args[0];
struct cfg80211_registered_device *dev;
mutex_lock(&cfg80211_drv_mutex);
list_for_each_entry(dev, &cfg80211_drv_list, list) {
if (++idx < start)
continue;
if (nl80211_send_wiphy(skb, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
dev) < 0)
break;
}
mutex_unlock(&cfg80211_drv_mutex);
cb->args[0] = idx;
return skb->len;
}
static int nl80211_get_wiphy(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
struct cfg80211_registered_device *dev;
dev = cfg80211_get_dev_from_info(info);
if (IS_ERR(dev))
return PTR_ERR(dev);
msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!msg)
goto out_err;
if (nl80211_send_wiphy(msg, info->snd_pid, info->snd_seq, 0, dev) < 0)
goto out_free;
cfg80211_put_dev(dev);
return genlmsg_unicast(msg, info->snd_pid);
out_free:
nlmsg_free(msg);
out_err:
cfg80211_put_dev(dev);
return -ENOBUFS;
}
static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
{
struct cfg80211_registered_device *rdev;
int result;
if (!info->attrs[NL80211_ATTR_WIPHY_NAME])
return -EINVAL;
rdev = cfg80211_get_dev_from_info(info);
if (IS_ERR(rdev))
return PTR_ERR(rdev);
result = cfg80211_dev_rename(rdev, nla_data(info->attrs[NL80211_ATTR_WIPHY_NAME]));
cfg80211_put_dev(rdev);
return result;
}
static int nl80211_send_iface(struct sk_buff *msg, u32 pid, u32 seq, int flags,
struct net_device *dev)
{
void *hdr;
hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_INTERFACE);
if (!hdr)
return -1;
NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);
NLA_PUT_STRING(msg, NL80211_ATTR_IFNAME, dev->name);
/* TODO: interface type */
return genlmsg_end(msg, hdr);
nla_put_failure:
return genlmsg_cancel(msg, hdr);
}
static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *cb)
{
int wp_idx = 0;
int if_idx = 0;
int wp_start = cb->args[0];
int if_start = cb->args[1];
struct cfg80211_registered_device *dev;
struct wireless_dev *wdev;
mutex_lock(&cfg80211_drv_mutex);
list_for_each_entry(dev, &cfg80211_drv_list, list) {
if (++wp_idx < wp_start)
continue;
if_idx = 0;
mutex_lock(&dev->devlist_mtx);
list_for_each_entry(wdev, &dev->netdev_list, list) {
if (++if_idx < if_start)
continue;
if (nl80211_send_iface(skb, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
wdev->netdev) < 0)
break;
}
mutex_unlock(&dev->devlist_mtx);
}
mutex_unlock(&cfg80211_drv_mutex);
cb->args[0] = wp_idx;
cb->args[1] = if_idx;
return skb->len;
}
static int nl80211_get_interface(struct sk_buff *skb, struct genl_info *info)
{
struct sk_buff *msg;
struct cfg80211_registered_device *dev;
struct net_device *netdev;
int err;
err = get_drv_dev_by_info_ifindex(info, &dev, &netdev);
if (err)
return err;
msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!msg)
goto out_err;
if (nl80211_send_iface(msg, info->snd_pid, info->snd_seq, 0, netdev) < 0)
goto out_free;
dev_put(netdev);
cfg80211_put_dev(dev);
return genlmsg_unicast(msg, info->snd_pid);
out_free:
nlmsg_free(msg);
out_err:
dev_put(netdev);
cfg80211_put_dev(dev);
return -ENOBUFS;
}
static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
{
struct cfg80211_registered_device *drv;
int err, ifindex;
enum nl80211_iftype type;
struct net_device *dev;
if (info->attrs[NL80211_ATTR_IFTYPE]) {
type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
if (type > NL80211_IFTYPE_MAX)
return -EINVAL;
} else
return -EINVAL;
err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
if (err)
return err;
ifindex = dev->ifindex;
dev_put(dev);
if (!drv->ops->change_virtual_intf) {
err = -EOPNOTSUPP;
goto unlock;
}
rtnl_lock();
err = drv->ops->change_virtual_intf(&drv->wiphy, ifindex, type);
rtnl_unlock();
unlock:
cfg80211_put_dev(drv);
return err;
}
static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
{
struct cfg80211_registered_device *drv;
int err;
enum nl80211_iftype type = NL80211_IFTYPE_UNSPECIFIED;
if (!info->attrs[NL80211_ATTR_IFNAME])
return -EINVAL;
if (info->attrs[NL80211_ATTR_IFTYPE]) {
type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
if (type > NL80211_IFTYPE_MAX)
return -EINVAL;
}
drv = cfg80211_get_dev_from_info(info);
if (IS_ERR(drv))
return PTR_ERR(drv);
if (!drv->ops->add_virtual_intf) {
err = -EOPNOTSUPP;
goto unlock;
}
rtnl_lock();
err = drv->ops->add_virtual_intf(&drv->wiphy,
nla_data(info->attrs[NL80211_ATTR_IFNAME]), type);
rtnl_unlock();
unlock:
cfg80211_put_dev(drv);
return err;
}
static int nl80211_del_interface(struct sk_buff *skb, struct genl_info *info)
{
struct cfg80211_registered_device *drv;
int ifindex, err;
struct net_device *dev;
err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
if (err)
return err;
ifindex = dev->ifindex;
dev_put(dev);
if (!drv->ops->del_virtual_intf) {
err = -EOPNOTSUPP;
goto out;
}
rtnl_lock();
err = drv->ops->del_virtual_intf(&drv->wiphy, ifindex);
rtnl_unlock();
out:
cfg80211_put_dev(drv);
return err;
}
static struct genl_ops nl80211_ops[] = {
{
.cmd = NL80211_CMD_GET_WIPHY,
.doit = nl80211_get_wiphy,
.dumpit = nl80211_dump_wiphy,
.policy = nl80211_policy,
/* can be retrieved by unprivileged users */
},
{
.cmd = NL80211_CMD_SET_WIPHY,
.doit = nl80211_set_wiphy,
.policy = nl80211_policy,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = NL80211_CMD_GET_INTERFACE,
.doit = nl80211_get_interface,
.dumpit = nl80211_dump_interface,
.policy = nl80211_policy,
/* can be retrieved by unprivileged users */
},
{
.cmd = NL80211_CMD_SET_INTERFACE,
.doit = nl80211_set_interface,
.policy = nl80211_policy,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = NL80211_CMD_NEW_INTERFACE,
.doit = nl80211_new_interface,
.policy = nl80211_policy,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = NL80211_CMD_DEL_INTERFACE,
.doit = nl80211_del_interface,
.policy = nl80211_policy,
.flags = GENL_ADMIN_PERM,
},
};
/* multicast groups */
static struct genl_multicast_group nl80211_config_mcgrp = {
.name = "config",
};
/* notification functions */
void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev)
{
struct sk_buff *msg;
msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
if (!msg)
return;
if (nl80211_send_wiphy(msg, 0, 0, 0, rdev) < 0) {
nlmsg_free(msg);
return;
}
genlmsg_multicast(msg, 0, nl80211_config_mcgrp.id, GFP_KERNEL);
}
/* initialisation/exit functions */
int nl80211_init(void)
{
int err, i;
err = genl_register_family(&nl80211_fam);
if (err)
return err;
for (i = 0; i < ARRAY_SIZE(nl80211_ops); i++) {
err = genl_register_ops(&nl80211_fam, &nl80211_ops[i]);
if (err)
goto err_out;
}
err = genl_register_mc_group(&nl80211_fam, &nl80211_config_mcgrp);
if (err)
goto err_out;
return 0;
err_out:
genl_unregister_family(&nl80211_fam);
return err;
}
void nl80211_exit(void)
{
genl_unregister_family(&nl80211_fam);
}
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