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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/file.h>
3#include <linux/mount.h>
4#include <linux/namei.h>
5#include <linux/utime.h>
6#include <linux/syscalls.h>
7#include <linux/uaccess.h>
8#include <linux/compat.h>
9#include <asm/unistd.h>
10
11static bool nsec_valid(long nsec)
12{
13 if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
14 return true;
15
16 return nsec >= 0 && nsec <= 999999999;
17}
18
19int vfs_utimes(const struct path *path, struct timespec64 *times)
20{
21 int error;
22 struct iattr newattrs;
23 struct inode *inode = path->dentry->d_inode;
24 struct inode *delegated_inode = NULL;
25
26 if (times) {
27 if (!nsec_valid(times[0].tv_nsec) ||
28 !nsec_valid(times[1].tv_nsec))
29 return -EINVAL;
30 if (times[0].tv_nsec == UTIME_NOW &&
31 times[1].tv_nsec == UTIME_NOW)
32 times = NULL;
33 }
34
35 error = mnt_want_write(path->mnt);
36 if (error)
37 goto out;
38
39 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
40 if (times) {
41 if (times[0].tv_nsec == UTIME_OMIT)
42 newattrs.ia_valid &= ~ATTR_ATIME;
43 else if (times[0].tv_nsec != UTIME_NOW) {
44 newattrs.ia_atime = times[0];
45 newattrs.ia_valid |= ATTR_ATIME_SET;
46 }
47
48 if (times[1].tv_nsec == UTIME_OMIT)
49 newattrs.ia_valid &= ~ATTR_MTIME;
50 else if (times[1].tv_nsec != UTIME_NOW) {
51 newattrs.ia_mtime = times[1];
52 newattrs.ia_valid |= ATTR_MTIME_SET;
53 }
54 /*
55 * Tell setattr_prepare(), that this is an explicit time
56 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
57 * were used.
58 */
59 newattrs.ia_valid |= ATTR_TIMES_SET;
60 } else {
61 newattrs.ia_valid |= ATTR_TOUCH;
62 }
63retry_deleg:
64 inode_lock(inode);
65 error = notify_change(mnt_user_ns(path->mnt), path->dentry, &newattrs,
66 &delegated_inode);
67 inode_unlock(inode);
68 if (delegated_inode) {
69 error = break_deleg_wait(&delegated_inode);
70 if (!error)
71 goto retry_deleg;
72 }
73
74 mnt_drop_write(path->mnt);
75out:
76 return error;
77}
78
79static int do_utimes_path(int dfd, const char __user *filename,
80 struct timespec64 *times, int flags)
81{
82 struct path path;
83 int lookup_flags = 0, error;
84
85 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
86 return -EINVAL;
87
88 if (!(flags & AT_SYMLINK_NOFOLLOW))
89 lookup_flags |= LOOKUP_FOLLOW;
90 if (flags & AT_EMPTY_PATH)
91 lookup_flags |= LOOKUP_EMPTY;
92
93retry:
94 error = user_path_at(dfd, filename, lookup_flags, &path);
95 if (error)
96 return error;
97
98 error = vfs_utimes(&path, times);
99 path_put(&path);
100 if (retry_estale(error, lookup_flags)) {
101 lookup_flags |= LOOKUP_REVAL;
102 goto retry;
103 }
104
105 return error;
106}
107
108static int do_utimes_fd(int fd, struct timespec64 *times, int flags)
109{
110 struct fd f;
111 int error;
112
113 if (flags)
114 return -EINVAL;
115
116 f = fdget(fd);
117 if (!f.file)
118 return -EBADF;
119 error = vfs_utimes(&f.file->f_path, times);
120 fdput(f);
121 return error;
122}
123
124/*
125 * do_utimes - change times on filename or file descriptor
126 * @dfd: open file descriptor, -1 or AT_FDCWD
127 * @filename: path name or NULL
128 * @times: new times or NULL
129 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
130 *
131 * If filename is NULL and dfd refers to an open file, then operate on
132 * the file. Otherwise look up filename, possibly using dfd as a
133 * starting point.
134 *
135 * If times==NULL, set access and modification to current time,
136 * must be owner or have write permission.
137 * Else, update from *times, must be owner or super user.
138 */
139long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
140 int flags)
141{
142 if (filename == NULL && dfd != AT_FDCWD)
143 return do_utimes_fd(dfd, times, flags);
144 return do_utimes_path(dfd, filename, times, flags);
145}
146
147SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
148 struct __kernel_timespec __user *, utimes, int, flags)
149{
150 struct timespec64 tstimes[2];
151
152 if (utimes) {
153 if ((get_timespec64(&tstimes[0], &utimes[0]) ||
154 get_timespec64(&tstimes[1], &utimes[1])))
155 return -EFAULT;
156
157 /* Nothing to do, we must not even check the path. */
158 if (tstimes[0].tv_nsec == UTIME_OMIT &&
159 tstimes[1].tv_nsec == UTIME_OMIT)
160 return 0;
161 }
162
163 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
164}
165
166#ifdef __ARCH_WANT_SYS_UTIME
167/*
168 * futimesat(), utimes() and utime() are older versions of utimensat()
169 * that are provided for compatibility with traditional C libraries.
170 * On modern architectures, we always use libc wrappers around
171 * utimensat() instead.
172 */
173static long do_futimesat(int dfd, const char __user *filename,
174 struct __kernel_old_timeval __user *utimes)
175{
176 struct __kernel_old_timeval times[2];
177 struct timespec64 tstimes[2];
178
179 if (utimes) {
180 if (copy_from_user(×, utimes, sizeof(times)))
181 return -EFAULT;
182
183 /* This test is needed to catch all invalid values. If we
184 would test only in do_utimes we would miss those invalid
185 values truncated by the multiplication with 1000. Note
186 that we also catch UTIME_{NOW,OMIT} here which are only
187 valid for utimensat. */
188 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
189 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
190 return -EINVAL;
191
192 tstimes[0].tv_sec = times[0].tv_sec;
193 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
194 tstimes[1].tv_sec = times[1].tv_sec;
195 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
196 }
197
198 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
199}
200
201
202SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
203 struct __kernel_old_timeval __user *, utimes)
204{
205 return do_futimesat(dfd, filename, utimes);
206}
207
208SYSCALL_DEFINE2(utimes, char __user *, filename,
209 struct __kernel_old_timeval __user *, utimes)
210{
211 return do_futimesat(AT_FDCWD, filename, utimes);
212}
213
214SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
215{
216 struct timespec64 tv[2];
217
218 if (times) {
219 if (get_user(tv[0].tv_sec, ×->actime) ||
220 get_user(tv[1].tv_sec, ×->modtime))
221 return -EFAULT;
222 tv[0].tv_nsec = 0;
223 tv[1].tv_nsec = 0;
224 }
225 return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
226}
227#endif
228
229#ifdef CONFIG_COMPAT_32BIT_TIME
230/*
231 * Not all architectures have sys_utime, so implement this in terms
232 * of sys_utimes.
233 */
234#ifdef __ARCH_WANT_SYS_UTIME32
235SYSCALL_DEFINE2(utime32, const char __user *, filename,
236 struct old_utimbuf32 __user *, t)
237{
238 struct timespec64 tv[2];
239
240 if (t) {
241 if (get_user(tv[0].tv_sec, &t->actime) ||
242 get_user(tv[1].tv_sec, &t->modtime))
243 return -EFAULT;
244 tv[0].tv_nsec = 0;
245 tv[1].tv_nsec = 0;
246 }
247 return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
248}
249#endif
250
251SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user *, filename, struct old_timespec32 __user *, t, int, flags)
252{
253 struct timespec64 tv[2];
254
255 if (t) {
256 if (get_old_timespec32(&tv[0], &t[0]) ||
257 get_old_timespec32(&tv[1], &t[1]))
258 return -EFAULT;
259
260 if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
261 return 0;
262 }
263 return do_utimes(dfd, filename, t ? tv : NULL, flags);
264}
265
266#ifdef __ARCH_WANT_SYS_UTIME32
267static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
268 struct old_timeval32 __user *t)
269{
270 struct timespec64 tv[2];
271
272 if (t) {
273 if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
274 get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
275 get_user(tv[1].tv_sec, &t[1].tv_sec) ||
276 get_user(tv[1].tv_nsec, &t[1].tv_usec))
277 return -EFAULT;
278 if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
279 tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
280 return -EINVAL;
281 tv[0].tv_nsec *= 1000;
282 tv[1].tv_nsec *= 1000;
283 }
284 return do_utimes(dfd, filename, t ? tv : NULL, 0);
285}
286
287SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd,
288 const char __user *, filename,
289 struct old_timeval32 __user *, t)
290{
291 return do_compat_futimesat(dfd, filename, t);
292}
293
294SYSCALL_DEFINE2(utimes_time32, const char __user *, filename, struct old_timeval32 __user *, t)
295{
296 return do_compat_futimesat(AT_FDCWD, filename, t);
297}
298#endif
299#endif
1// SPDX-License-Identifier: GPL-2.0
2#include <linux/file.h>
3#include <linux/mount.h>
4#include <linux/namei.h>
5#include <linux/utime.h>
6#include <linux/syscalls.h>
7#include <linux/uaccess.h>
8#include <linux/compat.h>
9#include <asm/unistd.h>
10
11static bool nsec_valid(long nsec)
12{
13 if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
14 return true;
15
16 return nsec >= 0 && nsec <= 999999999;
17}
18
19int vfs_utimes(const struct path *path, struct timespec64 *times)
20{
21 int error;
22 struct iattr newattrs;
23 struct inode *inode = path->dentry->d_inode;
24 struct inode *delegated_inode = NULL;
25
26 if (times) {
27 if (!nsec_valid(times[0].tv_nsec) ||
28 !nsec_valid(times[1].tv_nsec))
29 return -EINVAL;
30 if (times[0].tv_nsec == UTIME_NOW &&
31 times[1].tv_nsec == UTIME_NOW)
32 times = NULL;
33 }
34
35 error = mnt_want_write(path->mnt);
36 if (error)
37 goto out;
38
39 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
40 if (times) {
41 if (times[0].tv_nsec == UTIME_OMIT)
42 newattrs.ia_valid &= ~ATTR_ATIME;
43 else if (times[0].tv_nsec != UTIME_NOW) {
44 newattrs.ia_atime = times[0];
45 newattrs.ia_valid |= ATTR_ATIME_SET;
46 }
47
48 if (times[1].tv_nsec == UTIME_OMIT)
49 newattrs.ia_valid &= ~ATTR_MTIME;
50 else if (times[1].tv_nsec != UTIME_NOW) {
51 newattrs.ia_mtime = times[1];
52 newattrs.ia_valid |= ATTR_MTIME_SET;
53 }
54 /*
55 * Tell setattr_prepare(), that this is an explicit time
56 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
57 * were used.
58 */
59 newattrs.ia_valid |= ATTR_TIMES_SET;
60 } else {
61 newattrs.ia_valid |= ATTR_TOUCH;
62 }
63retry_deleg:
64 inode_lock(inode);
65 error = notify_change(mnt_user_ns(path->mnt), path->dentry, &newattrs,
66 &delegated_inode);
67 inode_unlock(inode);
68 if (delegated_inode) {
69 error = break_deleg_wait(&delegated_inode);
70 if (!error)
71 goto retry_deleg;
72 }
73
74 mnt_drop_write(path->mnt);
75out:
76 return error;
77}
78
79static int do_utimes_path(int dfd, const char __user *filename,
80 struct timespec64 *times, int flags)
81{
82 struct path path;
83 int lookup_flags = 0, error;
84
85 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
86 return -EINVAL;
87
88 if (!(flags & AT_SYMLINK_NOFOLLOW))
89 lookup_flags |= LOOKUP_FOLLOW;
90 if (flags & AT_EMPTY_PATH)
91 lookup_flags |= LOOKUP_EMPTY;
92
93retry:
94 error = user_path_at(dfd, filename, lookup_flags, &path);
95 if (error)
96 return error;
97
98 error = vfs_utimes(&path, times);
99 path_put(&path);
100 if (retry_estale(error, lookup_flags)) {
101 lookup_flags |= LOOKUP_REVAL;
102 goto retry;
103 }
104
105 return error;
106}
107
108static int do_utimes_fd(int fd, struct timespec64 *times, int flags)
109{
110 struct fd f;
111 int error;
112
113 if (flags)
114 return -EINVAL;
115
116 f = fdget(fd);
117 if (!f.file)
118 return -EBADF;
119 error = vfs_utimes(&f.file->f_path, times);
120 fdput(f);
121 return error;
122}
123
124/*
125 * do_utimes - change times on filename or file descriptor
126 * @dfd: open file descriptor, -1 or AT_FDCWD
127 * @filename: path name or NULL
128 * @times: new times or NULL
129 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
130 *
131 * If filename is NULL and dfd refers to an open file, then operate on
132 * the file. Otherwise look up filename, possibly using dfd as a
133 * starting point.
134 *
135 * If times==NULL, set access and modification to current time,
136 * must be owner or have write permission.
137 * Else, update from *times, must be owner or super user.
138 */
139long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
140 int flags)
141{
142 if (filename == NULL && dfd != AT_FDCWD)
143 return do_utimes_fd(dfd, times, flags);
144 return do_utimes_path(dfd, filename, times, flags);
145}
146
147SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
148 struct __kernel_timespec __user *, utimes, int, flags)
149{
150 struct timespec64 tstimes[2];
151
152 if (utimes) {
153 if ((get_timespec64(&tstimes[0], &utimes[0]) ||
154 get_timespec64(&tstimes[1], &utimes[1])))
155 return -EFAULT;
156
157 /* Nothing to do, we must not even check the path. */
158 if (tstimes[0].tv_nsec == UTIME_OMIT &&
159 tstimes[1].tv_nsec == UTIME_OMIT)
160 return 0;
161 }
162
163 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
164}
165
166#ifdef __ARCH_WANT_SYS_UTIME
167/*
168 * futimesat(), utimes() and utime() are older versions of utimensat()
169 * that are provided for compatibility with traditional C libraries.
170 * On modern architectures, we always use libc wrappers around
171 * utimensat() instead.
172 */
173static long do_futimesat(int dfd, const char __user *filename,
174 struct __kernel_old_timeval __user *utimes)
175{
176 struct __kernel_old_timeval times[2];
177 struct timespec64 tstimes[2];
178
179 if (utimes) {
180 if (copy_from_user(×, utimes, sizeof(times)))
181 return -EFAULT;
182
183 /* This test is needed to catch all invalid values. If we
184 would test only in do_utimes we would miss those invalid
185 values truncated by the multiplication with 1000. Note
186 that we also catch UTIME_{NOW,OMIT} here which are only
187 valid for utimensat. */
188 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
189 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
190 return -EINVAL;
191
192 tstimes[0].tv_sec = times[0].tv_sec;
193 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
194 tstimes[1].tv_sec = times[1].tv_sec;
195 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
196 }
197
198 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
199}
200
201
202SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
203 struct __kernel_old_timeval __user *, utimes)
204{
205 return do_futimesat(dfd, filename, utimes);
206}
207
208SYSCALL_DEFINE2(utimes, char __user *, filename,
209 struct __kernel_old_timeval __user *, utimes)
210{
211 return do_futimesat(AT_FDCWD, filename, utimes);
212}
213
214SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
215{
216 struct timespec64 tv[2];
217
218 if (times) {
219 if (get_user(tv[0].tv_sec, ×->actime) ||
220 get_user(tv[1].tv_sec, ×->modtime))
221 return -EFAULT;
222 tv[0].tv_nsec = 0;
223 tv[1].tv_nsec = 0;
224 }
225 return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
226}
227#endif
228
229#ifdef CONFIG_COMPAT_32BIT_TIME
230/*
231 * Not all architectures have sys_utime, so implement this in terms
232 * of sys_utimes.
233 */
234#ifdef __ARCH_WANT_SYS_UTIME32
235SYSCALL_DEFINE2(utime32, const char __user *, filename,
236 struct old_utimbuf32 __user *, t)
237{
238 struct timespec64 tv[2];
239
240 if (t) {
241 if (get_user(tv[0].tv_sec, &t->actime) ||
242 get_user(tv[1].tv_sec, &t->modtime))
243 return -EFAULT;
244 tv[0].tv_nsec = 0;
245 tv[1].tv_nsec = 0;
246 }
247 return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
248}
249#endif
250
251SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user *, filename, struct old_timespec32 __user *, t, int, flags)
252{
253 struct timespec64 tv[2];
254
255 if (t) {
256 if (get_old_timespec32(&tv[0], &t[0]) ||
257 get_old_timespec32(&tv[1], &t[1]))
258 return -EFAULT;
259
260 if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
261 return 0;
262 }
263 return do_utimes(dfd, filename, t ? tv : NULL, flags);
264}
265
266#ifdef __ARCH_WANT_SYS_UTIME32
267static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
268 struct old_timeval32 __user *t)
269{
270 struct timespec64 tv[2];
271
272 if (t) {
273 if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
274 get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
275 get_user(tv[1].tv_sec, &t[1].tv_sec) ||
276 get_user(tv[1].tv_nsec, &t[1].tv_usec))
277 return -EFAULT;
278 if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
279 tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
280 return -EINVAL;
281 tv[0].tv_nsec *= 1000;
282 tv[1].tv_nsec *= 1000;
283 }
284 return do_utimes(dfd, filename, t ? tv : NULL, 0);
285}
286
287SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd,
288 const char __user *, filename,
289 struct old_timeval32 __user *, t)
290{
291 return do_compat_futimesat(dfd, filename, t);
292}
293
294SYSCALL_DEFINE2(utimes_time32, const char __user *, filename, struct old_timeval32 __user *, t)
295{
296 return do_compat_futimesat(AT_FDCWD, filename, t);
297}
298#endif
299#endif