Commit e5d69b9f authored by Denis V. Lunev's avatar Denis V. Lunev Committed by David S. Miller

[ATM]: Oops reading net/atm/arp

cat /proc/net/atm/arp causes the NULL pointer dereference in the
get_proc_net+0xc/0x3a. This happens as proc_get_net believes that the
parent proc dir entry contains struct net.

Fix this assumption for "net/atm" case.

The problem is introduced by the commit c0097b07abf5f92ab135d024dd41bd2aada1512f
from Eric W. Biederman/Daniel Lezcano.
Signed-off-by: default avatarDenis V. Lunev <den@openvz.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8cced9ef
......@@ -96,6 +96,17 @@ static struct proc_dir_entry *proc_net_shadow(struct task_struct *task,
return task->nsproxy->net_ns->proc_net;
}
struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
struct proc_dir_entry *parent)
{
struct proc_dir_entry *pde;
pde = proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
if (pde != NULL)
pde->data = net;
return pde;
}
EXPORT_SYMBOL_GPL(proc_net_mkdir);
static __net_init int proc_net_ns_init(struct net *net)
{
struct proc_dir_entry *root, *netd, *net_statd;
......@@ -107,18 +118,16 @@ static __net_init int proc_net_ns_init(struct net *net)
goto out;
err = -EEXIST;
netd = proc_mkdir("net", root);
netd = proc_net_mkdir(net, "net", root);
if (!netd)
goto free_root;
err = -EEXIST;
net_statd = proc_mkdir("stat", netd);
net_statd = proc_net_mkdir(net, "stat", netd);
if (!net_statd)
goto free_net;
root->data = net;
netd->data = net;
net_statd->data = net;
net->proc_net_root = root;
net->proc_net = netd;
......
......@@ -201,6 +201,8 @@ static inline struct proc_dir_entry *create_proc_info_entry(const char *name,
extern struct proc_dir_entry *proc_net_fops_create(struct net *net,
const char *name, mode_t mode, const struct file_operations *fops);
extern void proc_net_remove(struct net *net, const char *name);
extern struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
struct proc_dir_entry *parent);
#else
......
......@@ -476,7 +476,7 @@ static void atm_proc_dirs_remove(void)
if (e->dirent)
remove_proc_entry(e->name, atm_proc_root);
}
remove_proc_entry("atm", init_net.proc_net);
proc_net_remove(&init_net, "atm");
}
int __init atm_proc_init(void)
......@@ -484,7 +484,7 @@ int __init atm_proc_init(void)
static struct atm_proc_entry *e;
int ret;
atm_proc_root = proc_mkdir("atm", init_net.proc_net);
atm_proc_root = proc_net_mkdir(&init_net, "atm", init_net.proc_net);
if (!atm_proc_root)
goto err_out;
for (e = atm_proc_ents; e->name; e++) {
......
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