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v6.2
  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/proc_fs.h>
  3#include <linux/nsproxy.h>
  4#include <linux/ptrace.h>
  5#include <linux/namei.h>
  6#include <linux/file.h>
  7#include <linux/utsname.h>
  8#include <net/net_namespace.h>
  9#include <linux/ipc_namespace.h>
 10#include <linux/pid_namespace.h>
 11#include <linux/user_namespace.h>
 12#include "internal.h"
 13
 14
 15static const struct proc_ns_operations *ns_entries[] = {
 16#ifdef CONFIG_NET_NS
 17	&netns_operations,
 18#endif
 19#ifdef CONFIG_UTS_NS
 20	&utsns_operations,
 21#endif
 22#ifdef CONFIG_IPC_NS
 23	&ipcns_operations,
 24#endif
 25#ifdef CONFIG_PID_NS
 26	&pidns_operations,
 27	&pidns_for_children_operations,
 28#endif
 29#ifdef CONFIG_USER_NS
 30	&userns_operations,
 31#endif
 32	&mntns_operations,
 33#ifdef CONFIG_CGROUPS
 34	&cgroupns_operations,
 35#endif
 36#ifdef CONFIG_TIME_NS
 37	&timens_operations,
 38	&timens_for_children_operations,
 39#endif
 40};
 41
 42static const char *proc_ns_get_link(struct dentry *dentry,
 43				    struct inode *inode,
 44				    struct delayed_call *done)
 45{
 46	const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
 47	struct task_struct *task;
 48	struct path ns_path;
 49	int error = -EACCES;
 50
 51	if (!dentry)
 52		return ERR_PTR(-ECHILD);
 53
 54	task = get_proc_task(inode);
 55	if (!task)
 56		return ERR_PTR(-EACCES);
 57
 58	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
 59		goto out;
 60
 61	error = ns_get_path(&ns_path, task, ns_ops);
 62	if (error)
 63		goto out;
 64
 65	error = nd_jump_link(&ns_path);
 66out:
 67	put_task_struct(task);
 68	return ERR_PTR(error);
 69}
 70
 71static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 72{
 73	struct inode *inode = d_inode(dentry);
 74	const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
 75	struct task_struct *task;
 76	char name[50];
 77	int res = -EACCES;
 78
 79	task = get_proc_task(inode);
 80	if (!task)
 81		return res;
 82
 83	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
 84		res = ns_get_name(name, sizeof(name), task, ns_ops);
 85		if (res >= 0)
 86			res = readlink_copy(buffer, buflen, name);
 87	}
 88	put_task_struct(task);
 89	return res;
 90}
 91
 92static const struct inode_operations proc_ns_link_inode_operations = {
 93	.readlink	= proc_ns_readlink,
 94	.get_link	= proc_ns_get_link,
 95	.setattr	= proc_setattr,
 96};
 97
 98static struct dentry *proc_ns_instantiate(struct dentry *dentry,
 99	struct task_struct *task, const void *ptr)
100{
101	const struct proc_ns_operations *ns_ops = ptr;
102	struct inode *inode;
103	struct proc_inode *ei;
104
105	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | S_IRWXUGO);
106	if (!inode)
107		return ERR_PTR(-ENOENT);
108
109	ei = PROC_I(inode);
110	inode->i_op = &proc_ns_link_inode_operations;
111	ei->ns_ops = ns_ops;
112	pid_update_inode(task, inode);
113
114	d_set_d_op(dentry, &pid_dentry_operations);
115	return d_splice_alias(inode, dentry);
116}
117
118static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
119{
120	struct task_struct *task = get_proc_task(file_inode(file));
121	const struct proc_ns_operations **entry, **last;
122
123	if (!task)
124		return -ENOENT;
125
126	if (!dir_emit_dots(file, ctx))
127		goto out;
128	if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
129		goto out;
130	entry = ns_entries + (ctx->pos - 2);
131	last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
132	while (entry <= last) {
133		const struct proc_ns_operations *ops = *entry;
134		if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name),
135				     proc_ns_instantiate, task, ops))
136			break;
137		ctx->pos++;
138		entry++;
139	}
140out:
141	put_task_struct(task);
142	return 0;
143}
144
145const struct file_operations proc_ns_dir_operations = {
146	.read		= generic_read_dir,
147	.iterate_shared	= proc_ns_dir_readdir,
148	.llseek		= generic_file_llseek,
149};
150
151static struct dentry *proc_ns_dir_lookup(struct inode *dir,
152				struct dentry *dentry, unsigned int flags)
153{
154	struct task_struct *task = get_proc_task(dir);
155	const struct proc_ns_operations **entry, **last;
156	unsigned int len = dentry->d_name.len;
157	struct dentry *res = ERR_PTR(-ENOENT);
158
159	if (!task)
160		goto out_no_task;
161
162	last = &ns_entries[ARRAY_SIZE(ns_entries)];
163	for (entry = ns_entries; entry < last; entry++) {
164		if (strlen((*entry)->name) != len)
165			continue;
166		if (!memcmp(dentry->d_name.name, (*entry)->name, len))
167			break;
168	}
169	if (entry == last)
170		goto out;
171
172	res = proc_ns_instantiate(dentry, task, *entry);
173out:
174	put_task_struct(task);
175out_no_task:
176	return res;
177}
178
179const struct inode_operations proc_ns_dir_inode_operations = {
180	.lookup		= proc_ns_dir_lookup,
181	.getattr	= pid_getattr,
182	.setattr	= proc_setattr,
183};
v5.4
  1// SPDX-License-Identifier: GPL-2.0
  2#include <linux/proc_fs.h>
  3#include <linux/nsproxy.h>
  4#include <linux/ptrace.h>
  5#include <linux/namei.h>
  6#include <linux/file.h>
  7#include <linux/utsname.h>
  8#include <net/net_namespace.h>
  9#include <linux/ipc_namespace.h>
 10#include <linux/pid_namespace.h>
 11#include <linux/user_namespace.h>
 12#include "internal.h"
 13
 14
 15static const struct proc_ns_operations *ns_entries[] = {
 16#ifdef CONFIG_NET_NS
 17	&netns_operations,
 18#endif
 19#ifdef CONFIG_UTS_NS
 20	&utsns_operations,
 21#endif
 22#ifdef CONFIG_IPC_NS
 23	&ipcns_operations,
 24#endif
 25#ifdef CONFIG_PID_NS
 26	&pidns_operations,
 27	&pidns_for_children_operations,
 28#endif
 29#ifdef CONFIG_USER_NS
 30	&userns_operations,
 31#endif
 32	&mntns_operations,
 33#ifdef CONFIG_CGROUPS
 34	&cgroupns_operations,
 35#endif
 
 
 
 
 36};
 37
 38static const char *proc_ns_get_link(struct dentry *dentry,
 39				    struct inode *inode,
 40				    struct delayed_call *done)
 41{
 42	const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
 43	struct task_struct *task;
 44	struct path ns_path;
 45	void *error = ERR_PTR(-EACCES);
 46
 47	if (!dentry)
 48		return ERR_PTR(-ECHILD);
 49
 50	task = get_proc_task(inode);
 51	if (!task)
 52		return error;
 53
 54	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
 55		error = ns_get_path(&ns_path, task, ns_ops);
 56		if (!error)
 57			nd_jump_link(&ns_path);
 58	}
 
 
 
 
 59	put_task_struct(task);
 60	return error;
 61}
 62
 63static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
 64{
 65	struct inode *inode = d_inode(dentry);
 66	const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
 67	struct task_struct *task;
 68	char name[50];
 69	int res = -EACCES;
 70
 71	task = get_proc_task(inode);
 72	if (!task)
 73		return res;
 74
 75	if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
 76		res = ns_get_name(name, sizeof(name), task, ns_ops);
 77		if (res >= 0)
 78			res = readlink_copy(buffer, buflen, name);
 79	}
 80	put_task_struct(task);
 81	return res;
 82}
 83
 84static const struct inode_operations proc_ns_link_inode_operations = {
 85	.readlink	= proc_ns_readlink,
 86	.get_link	= proc_ns_get_link,
 87	.setattr	= proc_setattr,
 88};
 89
 90static struct dentry *proc_ns_instantiate(struct dentry *dentry,
 91	struct task_struct *task, const void *ptr)
 92{
 93	const struct proc_ns_operations *ns_ops = ptr;
 94	struct inode *inode;
 95	struct proc_inode *ei;
 96
 97	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK | S_IRWXUGO);
 98	if (!inode)
 99		return ERR_PTR(-ENOENT);
100
101	ei = PROC_I(inode);
102	inode->i_op = &proc_ns_link_inode_operations;
103	ei->ns_ops = ns_ops;
104	pid_update_inode(task, inode);
105
106	d_set_d_op(dentry, &pid_dentry_operations);
107	return d_splice_alias(inode, dentry);
108}
109
110static int proc_ns_dir_readdir(struct file *file, struct dir_context *ctx)
111{
112	struct task_struct *task = get_proc_task(file_inode(file));
113	const struct proc_ns_operations **entry, **last;
114
115	if (!task)
116		return -ENOENT;
117
118	if (!dir_emit_dots(file, ctx))
119		goto out;
120	if (ctx->pos >= 2 + ARRAY_SIZE(ns_entries))
121		goto out;
122	entry = ns_entries + (ctx->pos - 2);
123	last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
124	while (entry <= last) {
125		const struct proc_ns_operations *ops = *entry;
126		if (!proc_fill_cache(file, ctx, ops->name, strlen(ops->name),
127				     proc_ns_instantiate, task, ops))
128			break;
129		ctx->pos++;
130		entry++;
131	}
132out:
133	put_task_struct(task);
134	return 0;
135}
136
137const struct file_operations proc_ns_dir_operations = {
138	.read		= generic_read_dir,
139	.iterate_shared	= proc_ns_dir_readdir,
140	.llseek		= generic_file_llseek,
141};
142
143static struct dentry *proc_ns_dir_lookup(struct inode *dir,
144				struct dentry *dentry, unsigned int flags)
145{
146	struct task_struct *task = get_proc_task(dir);
147	const struct proc_ns_operations **entry, **last;
148	unsigned int len = dentry->d_name.len;
149	struct dentry *res = ERR_PTR(-ENOENT);
150
151	if (!task)
152		goto out_no_task;
153
154	last = &ns_entries[ARRAY_SIZE(ns_entries)];
155	for (entry = ns_entries; entry < last; entry++) {
156		if (strlen((*entry)->name) != len)
157			continue;
158		if (!memcmp(dentry->d_name.name, (*entry)->name, len))
159			break;
160	}
161	if (entry == last)
162		goto out;
163
164	res = proc_ns_instantiate(dentry, task, *entry);
165out:
166	put_task_struct(task);
167out_no_task:
168	return res;
169}
170
171const struct inode_operations proc_ns_dir_inode_operations = {
172	.lookup		= proc_ns_dir_lookup,
173	.getattr	= pid_getattr,
174	.setattr	= proc_setattr,
175};