Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
3f07c014 | 2 | #include <linux/sched/signal.h> |
faf60af1 CG |
3 | #include <linux/errno.h> |
4 | #include <linux/dcache.h> | |
5 | #include <linux/path.h> | |
6 | #include <linux/fdtable.h> | |
7 | #include <linux/namei.h> | |
8 | #include <linux/pid.h> | |
9 | #include <linux/security.h> | |
ddd3e077 CG |
10 | #include <linux/file.h> |
11 | #include <linux/seq_file.h> | |
6c8c9031 | 12 | #include <linux/fs.h> |
faf60af1 CG |
13 | |
14 | #include <linux/proc_fs.h> | |
15 | ||
49d063cb | 16 | #include "../mount.h" |
faf60af1 CG |
17 | #include "internal.h" |
18 | #include "fd.h" | |
19 | ||
ddd3e077 | 20 | static int seq_show(struct seq_file *m, void *v) |
faf60af1 | 21 | { |
faf60af1 | 22 | struct files_struct *files = NULL; |
ddd3e077 CG |
23 | int f_flags = 0, ret = -ENOENT; |
24 | struct file *file = NULL; | |
25 | struct task_struct *task; | |
26 | ||
27 | task = get_proc_task(m->private); | |
28 | if (!task) | |
29 | return -ENOENT; | |
30 | ||
31 | files = get_files_struct(task); | |
32 | put_task_struct(task); | |
faf60af1 | 33 | |
faf60af1 | 34 | if (files) { |
771187d6 | 35 | unsigned int fd = proc_fd(m->private); |
ddd3e077 | 36 | |
faf60af1 CG |
37 | spin_lock(&files->file_lock); |
38 | file = fcheck_files(files, fd); | |
39 | if (file) { | |
ddd3e077 | 40 | struct fdtable *fdt = files_fdtable(files); |
faf60af1 | 41 | |
c6f3d811 | 42 | f_flags = file->f_flags; |
faf60af1 CG |
43 | if (close_on_exec(fd, fdt)) |
44 | f_flags |= O_CLOEXEC; | |
45 | ||
ddd3e077 CG |
46 | get_file(file); |
47 | ret = 0; | |
faf60af1 CG |
48 | } |
49 | spin_unlock(&files->file_lock); | |
50 | put_files_struct(files); | |
51 | } | |
ddd3e077 | 52 | |
6c8c9031 AV |
53 | if (ret) |
54 | return ret; | |
55 | ||
56 | seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n", | |
57 | (long long)file->f_pos, f_flags, | |
58 | real_mount(file->f_path.mnt)->mnt_id); | |
59 | ||
60 | show_fd_locks(m, file, files); | |
61 | if (seq_has_overflowed(m)) | |
62 | goto out; | |
63 | ||
64 | if (file->f_op->show_fdinfo) | |
65 | file->f_op->show_fdinfo(m, file); | |
ddd3e077 | 66 | |
6c8c9031 AV |
67 | out: |
68 | fput(file); | |
69 | return 0; | |
faf60af1 CG |
70 | } |
71 | ||
ddd3e077 CG |
72 | static int seq_fdinfo_open(struct inode *inode, struct file *file) |
73 | { | |
74 | return single_open(file, seq_show, inode); | |
75 | } | |
76 | ||
77 | static const struct file_operations proc_fdinfo_file_operations = { | |
78 | .open = seq_fdinfo_open, | |
79 | .read = seq_read, | |
80 | .llseek = seq_lseek, | |
81 | .release = single_release, | |
82 | }; | |
83 | ||
faf60af1 CG |
84 | static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags) |
85 | { | |
86 | struct files_struct *files; | |
87 | struct task_struct *task; | |
faf60af1 | 88 | struct inode *inode; |
771187d6 | 89 | unsigned int fd; |
faf60af1 CG |
90 | |
91 | if (flags & LOOKUP_RCU) | |
92 | return -ECHILD; | |
93 | ||
2b0143b5 | 94 | inode = d_inode(dentry); |
faf60af1 CG |
95 | task = get_proc_task(inode); |
96 | fd = proc_fd(inode); | |
97 | ||
98 | if (task) { | |
99 | files = get_files_struct(task); | |
100 | if (files) { | |
101 | struct file *file; | |
102 | ||
103 | rcu_read_lock(); | |
104 | file = fcheck_files(files, fd); | |
105 | if (file) { | |
106 | unsigned f_mode = file->f_mode; | |
107 | ||
108 | rcu_read_unlock(); | |
109 | put_files_struct(files); | |
110 | ||
68eb94f1 | 111 | task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid); |
faf60af1 CG |
112 | |
113 | if (S_ISLNK(inode->i_mode)) { | |
114 | unsigned i_mode = S_IFLNK; | |
115 | if (f_mode & FMODE_READ) | |
116 | i_mode |= S_IRUSR | S_IXUSR; | |
117 | if (f_mode & FMODE_WRITE) | |
118 | i_mode |= S_IWUSR | S_IXUSR; | |
119 | inode->i_mode = i_mode; | |
120 | } | |
121 | ||
122 | security_task_to_inode(task, inode); | |
123 | put_task_struct(task); | |
124 | return 1; | |
125 | } | |
126 | rcu_read_unlock(); | |
127 | put_files_struct(files); | |
128 | } | |
129 | put_task_struct(task); | |
130 | } | |
faf60af1 CG |
131 | return 0; |
132 | } | |
133 | ||
134 | static const struct dentry_operations tid_fd_dentry_operations = { | |
135 | .d_revalidate = tid_fd_revalidate, | |
136 | .d_delete = pid_delete_dentry, | |
137 | }; | |
138 | ||
139 | static int proc_fd_link(struct dentry *dentry, struct path *path) | |
140 | { | |
ddd3e077 CG |
141 | struct files_struct *files = NULL; |
142 | struct task_struct *task; | |
143 | int ret = -ENOENT; | |
144 | ||
2b0143b5 | 145 | task = get_proc_task(d_inode(dentry)); |
ddd3e077 CG |
146 | if (task) { |
147 | files = get_files_struct(task); | |
148 | put_task_struct(task); | |
149 | } | |
150 | ||
151 | if (files) { | |
771187d6 | 152 | unsigned int fd = proc_fd(d_inode(dentry)); |
ddd3e077 CG |
153 | struct file *fd_file; |
154 | ||
155 | spin_lock(&files->file_lock); | |
156 | fd_file = fcheck_files(files, fd); | |
157 | if (fd_file) { | |
158 | *path = fd_file->f_path; | |
159 | path_get(&fd_file->f_path); | |
160 | ret = 0; | |
161 | } | |
162 | spin_unlock(&files->file_lock); | |
163 | put_files_struct(files); | |
164 | } | |
165 | ||
166 | return ret; | |
faf60af1 CG |
167 | } |
168 | ||
c52a47ac | 169 | static int |
faf60af1 CG |
170 | proc_fd_instantiate(struct inode *dir, struct dentry *dentry, |
171 | struct task_struct *task, const void *ptr) | |
172 | { | |
faf60af1 CG |
173 | unsigned fd = (unsigned long)ptr; |
174 | struct proc_inode *ei; | |
175 | struct inode *inode; | |
176 | ||
db978da8 | 177 | inode = proc_pid_make_inode(dir->i_sb, task, S_IFLNK); |
faf60af1 CG |
178 | if (!inode) |
179 | goto out; | |
180 | ||
181 | ei = PROC_I(inode); | |
182 | ei->fd = fd; | |
183 | ||
faf60af1 CG |
184 | inode->i_op = &proc_pid_link_inode_operations; |
185 | inode->i_size = 64; | |
186 | ||
187 | ei->op.proc_get_link = proc_fd_link; | |
188 | ||
189 | d_set_d_op(dentry, &tid_fd_dentry_operations); | |
190 | d_add(dentry, inode); | |
191 | ||
192 | /* Close the race of the process dying before we return the dentry */ | |
193 | if (tid_fd_revalidate(dentry, 0)) | |
c52a47ac | 194 | return 0; |
faf60af1 | 195 | out: |
c52a47ac | 196 | return -ENOENT; |
faf60af1 CG |
197 | } |
198 | ||
199 | static struct dentry *proc_lookupfd_common(struct inode *dir, | |
200 | struct dentry *dentry, | |
201 | instantiate_t instantiate) | |
202 | { | |
203 | struct task_struct *task = get_proc_task(dir); | |
c52a47ac | 204 | int result = -ENOENT; |
dbcdb504 | 205 | unsigned fd = name_to_int(&dentry->d_name); |
faf60af1 CG |
206 | |
207 | if (!task) | |
208 | goto out_no_task; | |
209 | if (fd == ~0U) | |
210 | goto out; | |
211 | ||
212 | result = instantiate(dir, dentry, task, (void *)(unsigned long)fd); | |
213 | out: | |
214 | put_task_struct(task); | |
215 | out_no_task: | |
c52a47ac | 216 | return ERR_PTR(result); |
faf60af1 CG |
217 | } |
218 | ||
f0c3b509 AV |
219 | static int proc_readfd_common(struct file *file, struct dir_context *ctx, |
220 | instantiate_t instantiate) | |
faf60af1 | 221 | { |
f0c3b509 | 222 | struct task_struct *p = get_proc_task(file_inode(file)); |
faf60af1 | 223 | struct files_struct *files; |
f0c3b509 | 224 | unsigned int fd; |
faf60af1 | 225 | |
faf60af1 | 226 | if (!p) |
f0c3b509 | 227 | return -ENOENT; |
faf60af1 | 228 | |
f0c3b509 AV |
229 | if (!dir_emit_dots(file, ctx)) |
230 | goto out; | |
231 | files = get_files_struct(p); | |
232 | if (!files) | |
233 | goto out; | |
234 | ||
235 | rcu_read_lock(); | |
236 | for (fd = ctx->pos - 2; | |
237 | fd < files_fdtable(files)->max_fds; | |
238 | fd++, ctx->pos++) { | |
e3912ac3 | 239 | char name[10 + 1]; |
f0c3b509 AV |
240 | int len; |
241 | ||
242 | if (!fcheck_files(files, fd)) | |
243 | continue; | |
244 | rcu_read_unlock(); | |
245 | ||
771187d6 | 246 | len = snprintf(name, sizeof(name), "%u", fd); |
f0c3b509 AV |
247 | if (!proc_fill_cache(file, ctx, |
248 | name, len, instantiate, p, | |
249 | (void *)(unsigned long)fd)) | |
250 | goto out_fd_loop; | |
3cc4a84e | 251 | cond_resched(); |
f0c3b509 | 252 | rcu_read_lock(); |
faf60af1 | 253 | } |
f0c3b509 AV |
254 | rcu_read_unlock(); |
255 | out_fd_loop: | |
256 | put_files_struct(files); | |
faf60af1 CG |
257 | out: |
258 | put_task_struct(p); | |
f0c3b509 | 259 | return 0; |
faf60af1 CG |
260 | } |
261 | ||
f0c3b509 | 262 | static int proc_readfd(struct file *file, struct dir_context *ctx) |
faf60af1 | 263 | { |
f0c3b509 | 264 | return proc_readfd_common(file, ctx, proc_fd_instantiate); |
faf60af1 CG |
265 | } |
266 | ||
267 | const struct file_operations proc_fd_operations = { | |
268 | .read = generic_read_dir, | |
f50752ea AV |
269 | .iterate_shared = proc_readfd, |
270 | .llseek = generic_file_llseek, | |
faf60af1 CG |
271 | }; |
272 | ||
273 | static struct dentry *proc_lookupfd(struct inode *dir, struct dentry *dentry, | |
274 | unsigned int flags) | |
275 | { | |
276 | return proc_lookupfd_common(dir, dentry, proc_fd_instantiate); | |
277 | } | |
278 | ||
279 | /* | |
280 | * /proc/pid/fd needs a special permission handler so that a process can still | |
281 | * access /proc/self/fd after it has executed a setuid(). | |
282 | */ | |
283 | int proc_fd_permission(struct inode *inode, int mask) | |
284 | { | |
54708d28 ON |
285 | struct task_struct *p; |
286 | int rv; | |
287 | ||
288 | rv = generic_permission(inode, mask); | |
faf60af1 | 289 | if (rv == 0) |
54708d28 ON |
290 | return rv; |
291 | ||
292 | rcu_read_lock(); | |
293 | p = pid_task(proc_pid(inode), PIDTYPE_PID); | |
294 | if (p && same_thread_group(p, current)) | |
faf60af1 | 295 | rv = 0; |
54708d28 ON |
296 | rcu_read_unlock(); |
297 | ||
faf60af1 CG |
298 | return rv; |
299 | } | |
300 | ||
301 | const struct inode_operations proc_fd_inode_operations = { | |
302 | .lookup = proc_lookupfd, | |
303 | .permission = proc_fd_permission, | |
304 | .setattr = proc_setattr, | |
305 | }; | |
306 | ||
c52a47ac | 307 | static int |
faf60af1 CG |
308 | proc_fdinfo_instantiate(struct inode *dir, struct dentry *dentry, |
309 | struct task_struct *task, const void *ptr) | |
310 | { | |
faf60af1 CG |
311 | unsigned fd = (unsigned long)ptr; |
312 | struct proc_inode *ei; | |
313 | struct inode *inode; | |
314 | ||
db978da8 | 315 | inode = proc_pid_make_inode(dir->i_sb, task, S_IFREG | S_IRUSR); |
faf60af1 CG |
316 | if (!inode) |
317 | goto out; | |
318 | ||
319 | ei = PROC_I(inode); | |
320 | ei->fd = fd; | |
321 | ||
faf60af1 CG |
322 | inode->i_fop = &proc_fdinfo_file_operations; |
323 | ||
324 | d_set_d_op(dentry, &tid_fd_dentry_operations); | |
325 | d_add(dentry, inode); | |
326 | ||
327 | /* Close the race of the process dying before we return the dentry */ | |
328 | if (tid_fd_revalidate(dentry, 0)) | |
c52a47ac | 329 | return 0; |
faf60af1 | 330 | out: |
c52a47ac | 331 | return -ENOENT; |
faf60af1 CG |
332 | } |
333 | ||
334 | static struct dentry * | |
335 | proc_lookupfdinfo(struct inode *dir, struct dentry *dentry, unsigned int flags) | |
336 | { | |
337 | return proc_lookupfd_common(dir, dentry, proc_fdinfo_instantiate); | |
338 | } | |
339 | ||
f0c3b509 | 340 | static int proc_readfdinfo(struct file *file, struct dir_context *ctx) |
faf60af1 | 341 | { |
f0c3b509 | 342 | return proc_readfd_common(file, ctx, |
faf60af1 CG |
343 | proc_fdinfo_instantiate); |
344 | } | |
345 | ||
346 | const struct inode_operations proc_fdinfo_inode_operations = { | |
347 | .lookup = proc_lookupfdinfo, | |
348 | .setattr = proc_setattr, | |
349 | }; | |
350 | ||
351 | const struct file_operations proc_fdinfo_operations = { | |
352 | .read = generic_read_dir, | |
f50752ea AV |
353 | .iterate_shared = proc_readfdinfo, |
354 | .llseek = generic_file_llseek, | |
faf60af1 | 355 | }; |