[PATCH 2.6.25] [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: Denis V. Lunev <den@openvz.org> --- diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c index cfc4f6c..4823c96 100644 --- a/fs/proc/proc_net.c +++ b/fs/proc/proc_net.c @@ -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; diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index a531682..8f92546 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -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 diff --git a/net/atm/proc.c b/net/atm/proc.c index 5d9d5ff..565e75e 100644 --- a/net/atm/proc.c +++ b/net/atm/proc.c @@ -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++) {
Re: [PATCH 2.6.25] [ATM] Oops reading net/atm/arp
From: "Denis V. Lunev" <den@openvz.org> Date: Thu, 10 Jan 2008 14:28:53 +0300 > 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: Denis V. Lunev <den@openvz.org> Applied, thanks.