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