diff options
Diffstat (limited to 'security/commoncap.c')
-rw-r--r-- | security/commoncap.c | 830 |
1 files changed, 537 insertions, 293 deletions
diff --git a/security/commoncap.c b/security/commoncap.c index 3976613db829..79713545cd63 100644 --- a/security/commoncap.c +++ b/security/commoncap.c | |||
@@ -8,6 +8,7 @@ | |||
8 | */ | 8 | */ |
9 | 9 | ||
10 | #include <linux/capability.h> | 10 | #include <linux/capability.h> |
11 | #include <linux/audit.h> | ||
11 | #include <linux/module.h> | 12 | #include <linux/module.h> |
12 | #include <linux/init.h> | 13 | #include <linux/init.h> |
13 | #include <linux/kernel.h> | 14 | #include <linux/kernel.h> |
@@ -29,7 +30,7 @@ | |||
29 | 30 | ||
30 | int cap_netlink_send(struct sock *sk, struct sk_buff *skb) | 31 | int cap_netlink_send(struct sock *sk, struct sk_buff *skb) |
31 | { | 32 | { |
32 | NETLINK_CB(skb).eff_cap = current->cap_effective; | 33 | NETLINK_CB(skb).eff_cap = current_cap(); |
33 | return 0; | 34 | return 0; |
34 | } | 35 | } |
35 | 36 | ||
@@ -39,23 +40,41 @@ int cap_netlink_recv(struct sk_buff *skb, int cap) | |||
39 | return -EPERM; | 40 | return -EPERM; |
40 | return 0; | 41 | return 0; |
41 | } | 42 | } |
42 | |||
43 | EXPORT_SYMBOL(cap_netlink_recv); | 43 | EXPORT_SYMBOL(cap_netlink_recv); |
44 | 44 | ||
45 | /* | 45 | /** |
46 | * cap_capable - Determine whether a task has a particular effective capability | ||
47 | * @tsk: The task to query | ||
48 | * @cap: The capability to check for | ||
49 | * @audit: Whether to write an audit message or not | ||
50 | * | ||
51 | * Determine whether the nominated task has the specified capability amongst | ||
52 | * its effective set, returning 0 if it does, -ve if it does not. | ||
53 | * | ||
46 | * NOTE WELL: cap_capable() cannot be used like the kernel's capable() | 54 | * NOTE WELL: cap_capable() cannot be used like the kernel's capable() |
47 | * function. That is, it has the reverse semantics: cap_capable() | 55 | * function. That is, it has the reverse semantics: cap_capable() returns 0 |
48 | * returns 0 when a task has a capability, but the kernel's capable() | 56 | * when a task has a capability, but the kernel's capable() returns 1 for this |
49 | * returns 1 for this case. | 57 | * case. |
50 | */ | 58 | */ |
51 | int cap_capable (struct task_struct *tsk, int cap) | 59 | int cap_capable(struct task_struct *tsk, int cap, int audit) |
52 | { | 60 | { |
61 | __u32 cap_raised; | ||
62 | |||
53 | /* Derived from include/linux/sched.h:capable. */ | 63 | /* Derived from include/linux/sched.h:capable. */ |
54 | if (cap_raised(tsk->cap_effective, cap)) | 64 | rcu_read_lock(); |
55 | return 0; | 65 | cap_raised = cap_raised(__task_cred(tsk)->cap_effective, cap); |
56 | return -EPERM; | 66 | rcu_read_unlock(); |
67 | return cap_raised ? 0 : -EPERM; | ||
57 | } | 68 | } |
58 | 69 | ||
70 | /** | ||
71 | * cap_settime - Determine whether the current process may set the system clock | ||
72 | * @ts: The time to set | ||
73 | * @tz: The timezone to set | ||
74 | * | ||
75 | * Determine whether the current process may set the system clock and timezone | ||
76 | * information, returning 0 if permission granted, -ve if denied. | ||
77 | */ | ||
59 | int cap_settime(struct timespec *ts, struct timezone *tz) | 78 | int cap_settime(struct timespec *ts, struct timezone *tz) |
60 | { | 79 | { |
61 | if (!capable(CAP_SYS_TIME)) | 80 | if (!capable(CAP_SYS_TIME)) |
@@ -63,121 +82,157 @@ int cap_settime(struct timespec *ts, struct timezone *tz) | |||
63 | return 0; | 82 | return 0; |
64 | } | 83 | } |
65 | 84 | ||
85 | /** | ||
86 | * cap_ptrace_may_access - Determine whether the current process may access | ||
87 | * another | ||
88 | * @child: The process to be accessed | ||
89 | * @mode: The mode of attachment. | ||
90 | * | ||
91 | * Determine whether a process may access another, returning 0 if permission | ||
92 | * granted, -ve if denied. | ||
93 | */ | ||
66 | int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) | 94 | int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) |
67 | { | 95 | { |
68 | /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ | 96 | int ret = 0; |
69 | if (cap_issubset(child->cap_permitted, current->cap_permitted)) | 97 | |
70 | return 0; | 98 | rcu_read_lock(); |
71 | if (capable(CAP_SYS_PTRACE)) | 99 | if (!cap_issubset(__task_cred(child)->cap_permitted, |
72 | return 0; | 100 | current_cred()->cap_permitted) && |
73 | return -EPERM; | 101 | !capable(CAP_SYS_PTRACE)) |
102 | ret = -EPERM; | ||
103 | rcu_read_unlock(); | ||
104 | return ret; | ||
74 | } | 105 | } |
75 | 106 | ||
107 | /** | ||
108 | * cap_ptrace_traceme - Determine whether another process may trace the current | ||
109 | * @parent: The task proposed to be the tracer | ||
110 | * | ||
111 | * Determine whether the nominated task is permitted to trace the current | ||
112 | * process, returning 0 if permission is granted, -ve if denied. | ||
113 | */ | ||
76 | int cap_ptrace_traceme(struct task_struct *parent) | 114 | int cap_ptrace_traceme(struct task_struct *parent) |
77 | { | 115 | { |
78 | /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ | 116 | int ret = 0; |
79 | if (cap_issubset(current->cap_permitted, parent->cap_permitted)) | 117 | |
80 | return 0; | 118 | rcu_read_lock(); |
81 | if (has_capability(parent, CAP_SYS_PTRACE)) | 119 | if (!cap_issubset(current_cred()->cap_permitted, |
82 | return 0; | 120 | __task_cred(parent)->cap_permitted) && |
83 | return -EPERM; | 121 | !has_capability(parent, CAP_SYS_PTRACE)) |
122 | ret = -EPERM; | ||
123 | rcu_read_unlock(); | ||
124 | return ret; | ||
84 | } | 125 | } |
85 | 126 | ||
86 | int cap_capget (struct task_struct *target, kernel_cap_t *effective, | 127 | /** |
87 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | 128 | * cap_capget - Retrieve a task's capability sets |
129 | * @target: The task from which to retrieve the capability sets | ||
130 | * @effective: The place to record the effective set | ||
131 | * @inheritable: The place to record the inheritable set | ||
132 | * @permitted: The place to record the permitted set | ||
133 | * | ||
134 | * This function retrieves the capabilities of the nominated task and returns | ||
135 | * them to the caller. | ||
136 | */ | ||
137 | int cap_capget(struct task_struct *target, kernel_cap_t *effective, | ||
138 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | ||
88 | { | 139 | { |
140 | const struct cred *cred; | ||
141 | |||
89 | /* Derived from kernel/capability.c:sys_capget. */ | 142 | /* Derived from kernel/capability.c:sys_capget. */ |
90 | *effective = target->cap_effective; | 143 | rcu_read_lock(); |
91 | *inheritable = target->cap_inheritable; | 144 | cred = __task_cred(target); |
92 | *permitted = target->cap_permitted; | 145 | *effective = cred->cap_effective; |
146 | *inheritable = cred->cap_inheritable; | ||
147 | *permitted = cred->cap_permitted; | ||
148 | rcu_read_unlock(); | ||
93 | return 0; | 149 | return 0; |
94 | } | 150 | } |
95 | 151 | ||
96 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | 152 | /* |
97 | 153 | * Determine whether the inheritable capabilities are limited to the old | |
98 | static inline int cap_block_setpcap(struct task_struct *target) | 154 | * permitted set. Returns 1 if they are limited, 0 if they are not. |
99 | { | 155 | */ |
100 | /* | ||
101 | * No support for remote process capability manipulation with | ||
102 | * filesystem capability support. | ||
103 | */ | ||
104 | return (target != current); | ||
105 | } | ||
106 | |||
107 | static inline int cap_inh_is_capped(void) | 156 | static inline int cap_inh_is_capped(void) |
108 | { | 157 | { |
109 | /* | 158 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES |
110 | * Return 1 if changes to the inheritable set are limited | ||
111 | * to the old permitted set. That is, if the current task | ||
112 | * does *not* possess the CAP_SETPCAP capability. | ||
113 | */ | ||
114 | return (cap_capable(current, CAP_SETPCAP) != 0); | ||
115 | } | ||
116 | |||
117 | static inline int cap_limit_ptraced_target(void) { return 1; } | ||
118 | |||
119 | #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ | ||
120 | 159 | ||
121 | static inline int cap_block_setpcap(struct task_struct *t) { return 0; } | 160 | /* they are so limited unless the current task has the CAP_SETPCAP |
122 | static inline int cap_inh_is_capped(void) { return 1; } | 161 | * capability |
123 | static inline int cap_limit_ptraced_target(void) | 162 | */ |
124 | { | 163 | if (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0) |
125 | return !capable(CAP_SETPCAP); | 164 | return 0; |
165 | #endif | ||
166 | return 1; | ||
126 | } | 167 | } |
127 | 168 | ||
128 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | 169 | /** |
129 | 170 | * cap_capset - Validate and apply proposed changes to current's capabilities | |
130 | int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, | 171 | * @new: The proposed new credentials; alterations should be made here |
131 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | 172 | * @old: The current task's current credentials |
132 | { | 173 | * @effective: A pointer to the proposed new effective capabilities set |
133 | if (cap_block_setpcap(target)) { | 174 | * @inheritable: A pointer to the proposed new inheritable capabilities set |
134 | return -EPERM; | 175 | * @permitted: A pointer to the proposed new permitted capabilities set |
135 | } | 176 | * |
136 | if (cap_inh_is_capped() | 177 | * This function validates and applies a proposed mass change to the current |
137 | && !cap_issubset(*inheritable, | 178 | * process's capability sets. The changes are made to the proposed new |
138 | cap_combine(target->cap_inheritable, | 179 | * credentials, and assuming no error, will be committed by the caller of LSM. |
139 | current->cap_permitted))) { | 180 | */ |
181 | int cap_capset(struct cred *new, | ||
182 | const struct cred *old, | ||
183 | const kernel_cap_t *effective, | ||
184 | const kernel_cap_t *inheritable, | ||
185 | const kernel_cap_t *permitted) | ||
186 | { | ||
187 | if (cap_inh_is_capped() && | ||
188 | !cap_issubset(*inheritable, | ||
189 | cap_combine(old->cap_inheritable, | ||
190 | old->cap_permitted))) | ||
140 | /* incapable of using this inheritable set */ | 191 | /* incapable of using this inheritable set */ |
141 | return -EPERM; | 192 | return -EPERM; |
142 | } | 193 | |
143 | if (!cap_issubset(*inheritable, | 194 | if (!cap_issubset(*inheritable, |
144 | cap_combine(target->cap_inheritable, | 195 | cap_combine(old->cap_inheritable, |
145 | current->cap_bset))) { | 196 | old->cap_bset))) |
146 | /* no new pI capabilities outside bounding set */ | 197 | /* no new pI capabilities outside bounding set */ |
147 | return -EPERM; | 198 | return -EPERM; |
148 | } | ||
149 | 199 | ||
150 | /* verify restrictions on target's new Permitted set */ | 200 | /* verify restrictions on target's new Permitted set */ |
151 | if (!cap_issubset (*permitted, | 201 | if (!cap_issubset(*permitted, old->cap_permitted)) |
152 | cap_combine (target->cap_permitted, | ||
153 | current->cap_permitted))) { | ||
154 | return -EPERM; | 202 | return -EPERM; |
155 | } | ||
156 | 203 | ||
157 | /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ | 204 | /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ |
158 | if (!cap_issubset (*effective, *permitted)) { | 205 | if (!cap_issubset(*effective, *permitted)) |
159 | return -EPERM; | 206 | return -EPERM; |
160 | } | ||
161 | 207 | ||
208 | new->cap_effective = *effective; | ||
209 | new->cap_inheritable = *inheritable; | ||
210 | new->cap_permitted = *permitted; | ||
162 | return 0; | 211 | return 0; |
163 | } | 212 | } |
164 | 213 | ||
165 | void cap_capset_set (struct task_struct *target, kernel_cap_t *effective, | 214 | /* |
166 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | 215 | * Clear proposed capability sets for execve(). |
167 | { | 216 | */ |
168 | target->cap_effective = *effective; | ||
169 | target->cap_inheritable = *inheritable; | ||
170 | target->cap_permitted = *permitted; | ||
171 | } | ||
172 | |||
173 | static inline void bprm_clear_caps(struct linux_binprm *bprm) | 217 | static inline void bprm_clear_caps(struct linux_binprm *bprm) |
174 | { | 218 | { |
175 | cap_clear(bprm->cap_post_exec_permitted); | 219 | cap_clear(bprm->cred->cap_permitted); |
176 | bprm->cap_effective = false; | 220 | bprm->cap_effective = false; |
177 | } | 221 | } |
178 | 222 | ||
179 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | 223 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES |
180 | 224 | ||
225 | /** | ||
226 | * cap_inode_need_killpriv - Determine if inode change affects privileges | ||
227 | * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV | ||
228 | * | ||
229 | * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV | ||
230 | * affects the security markings on that inode, and if it is, should | ||
231 | * inode_killpriv() be invoked or the change rejected? | ||
232 | * | ||
233 | * Returns 0 if granted; +ve if granted, but inode_killpriv() is required; and | ||
234 | * -ve to deny the change. | ||
235 | */ | ||
181 | int cap_inode_need_killpriv(struct dentry *dentry) | 236 | int cap_inode_need_killpriv(struct dentry *dentry) |
182 | { | 237 | { |
183 | struct inode *inode = dentry->d_inode; | 238 | struct inode *inode = dentry->d_inode; |
@@ -192,6 +247,14 @@ int cap_inode_need_killpriv(struct dentry *dentry) | |||
192 | return 1; | 247 | return 1; |
193 | } | 248 | } |
194 | 249 | ||
250 | /** | ||
251 | * cap_inode_killpriv - Erase the security markings on an inode | ||
252 | * @dentry: The inode/dentry to alter | ||
253 | * | ||
254 | * Erase the privilege-enhancing security markings on an inode. | ||
255 | * | ||
256 | * Returns 0 if successful, -ve on error. | ||
257 | */ | ||
195 | int cap_inode_killpriv(struct dentry *dentry) | 258 | int cap_inode_killpriv(struct dentry *dentry) |
196 | { | 259 | { |
197 | struct inode *inode = dentry->d_inode; | 260 | struct inode *inode = dentry->d_inode; |
@@ -202,19 +265,75 @@ int cap_inode_killpriv(struct dentry *dentry) | |||
202 | return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); | 265 | return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); |
203 | } | 266 | } |
204 | 267 | ||
205 | static inline int cap_from_disk(struct vfs_cap_data *caps, | 268 | /* |
206 | struct linux_binprm *bprm, unsigned size) | 269 | * Calculate the new process capability sets from the capability sets attached |
270 | * to a file. | ||
271 | */ | ||
272 | static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, | ||
273 | struct linux_binprm *bprm, | ||
274 | bool *effective) | ||
275 | { | ||
276 | struct cred *new = bprm->cred; | ||
277 | unsigned i; | ||
278 | int ret = 0; | ||
279 | |||
280 | if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE) | ||
281 | *effective = true; | ||
282 | |||
283 | CAP_FOR_EACH_U32(i) { | ||
284 | __u32 permitted = caps->permitted.cap[i]; | ||
285 | __u32 inheritable = caps->inheritable.cap[i]; | ||
286 | |||
287 | /* | ||
288 | * pP' = (X & fP) | (pI & fI) | ||
289 | */ | ||
290 | new->cap_permitted.cap[i] = | ||
291 | (new->cap_bset.cap[i] & permitted) | | ||
292 | (new->cap_inheritable.cap[i] & inheritable); | ||
293 | |||
294 | if (permitted & ~new->cap_permitted.cap[i]) | ||
295 | /* insufficient to execute correctly */ | ||
296 | ret = -EPERM; | ||
297 | } | ||
298 | |||
299 | /* | ||
300 | * For legacy apps, with no internal support for recognizing they | ||
301 | * do not have enough capabilities, we return an error if they are | ||
302 | * missing some "forced" (aka file-permitted) capabilities. | ||
303 | */ | ||
304 | return *effective ? ret : 0; | ||
305 | } | ||
306 | |||
307 | /* | ||
308 | * Extract the on-exec-apply capability sets for an executable file. | ||
309 | */ | ||
310 | int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) | ||
207 | { | 311 | { |
312 | struct inode *inode = dentry->d_inode; | ||
208 | __u32 magic_etc; | 313 | __u32 magic_etc; |
209 | unsigned tocopy, i; | 314 | unsigned tocopy, i; |
210 | int ret; | 315 | int size; |
316 | struct vfs_cap_data caps; | ||
317 | |||
318 | memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); | ||
319 | |||
320 | if (!inode || !inode->i_op || !inode->i_op->getxattr) | ||
321 | return -ENODATA; | ||
322 | |||
323 | size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps, | ||
324 | XATTR_CAPS_SZ); | ||
325 | if (size == -ENODATA || size == -EOPNOTSUPP) | ||
326 | /* no data, that's ok */ | ||
327 | return -ENODATA; | ||
328 | if (size < 0) | ||
329 | return size; | ||
211 | 330 | ||
212 | if (size < sizeof(magic_etc)) | 331 | if (size < sizeof(magic_etc)) |
213 | return -EINVAL; | 332 | return -EINVAL; |
214 | 333 | ||
215 | magic_etc = le32_to_cpu(caps->magic_etc); | 334 | cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc); |
216 | 335 | ||
217 | switch ((magic_etc & VFS_CAP_REVISION_MASK)) { | 336 | switch (magic_etc & VFS_CAP_REVISION_MASK) { |
218 | case VFS_CAP_REVISION_1: | 337 | case VFS_CAP_REVISION_1: |
219 | if (size != XATTR_CAPS_SZ_1) | 338 | if (size != XATTR_CAPS_SZ_1) |
220 | return -EINVAL; | 339 | return -EINVAL; |
@@ -229,77 +348,48 @@ static inline int cap_from_disk(struct vfs_cap_data *caps, | |||
229 | return -EINVAL; | 348 | return -EINVAL; |
230 | } | 349 | } |
231 | 350 | ||
232 | if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) { | ||
233 | bprm->cap_effective = true; | ||
234 | } else { | ||
235 | bprm->cap_effective = false; | ||
236 | } | ||
237 | |||
238 | ret = 0; | ||
239 | |||
240 | CAP_FOR_EACH_U32(i) { | 351 | CAP_FOR_EACH_U32(i) { |
241 | __u32 value_cpu; | 352 | if (i >= tocopy) |
242 | 353 | break; | |
243 | if (i >= tocopy) { | 354 | cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted); |
244 | /* | 355 | cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable); |
245 | * Legacy capability sets have no upper bits | ||
246 | */ | ||
247 | bprm->cap_post_exec_permitted.cap[i] = 0; | ||
248 | continue; | ||
249 | } | ||
250 | /* | ||
251 | * pP' = (X & fP) | (pI & fI) | ||
252 | */ | ||
253 | value_cpu = le32_to_cpu(caps->data[i].permitted); | ||
254 | bprm->cap_post_exec_permitted.cap[i] = | ||
255 | (current->cap_bset.cap[i] & value_cpu) | | ||
256 | (current->cap_inheritable.cap[i] & | ||
257 | le32_to_cpu(caps->data[i].inheritable)); | ||
258 | if (value_cpu & ~bprm->cap_post_exec_permitted.cap[i]) { | ||
259 | /* | ||
260 | * insufficient to execute correctly | ||
261 | */ | ||
262 | ret = -EPERM; | ||
263 | } | ||
264 | } | 356 | } |
265 | 357 | ||
266 | /* | 358 | return 0; |
267 | * For legacy apps, with no internal support for recognizing they | ||
268 | * do not have enough capabilities, we return an error if they are | ||
269 | * missing some "forced" (aka file-permitted) capabilities. | ||
270 | */ | ||
271 | return bprm->cap_effective ? ret : 0; | ||
272 | } | 359 | } |
273 | 360 | ||
274 | /* Locate any VFS capabilities: */ | 361 | /* |
275 | static int get_file_caps(struct linux_binprm *bprm) | 362 | * Attempt to get the on-exec apply capability sets for an executable file from |
363 | * its xattrs and, if present, apply them to the proposed credentials being | ||
364 | * constructed by execve(). | ||
365 | */ | ||
366 | static int get_file_caps(struct linux_binprm *bprm, bool *effective) | ||
276 | { | 367 | { |
277 | struct dentry *dentry; | 368 | struct dentry *dentry; |
278 | int rc = 0; | 369 | int rc = 0; |
279 | struct vfs_cap_data vcaps; | 370 | struct cpu_vfs_cap_data vcaps; |
280 | struct inode *inode; | ||
281 | 371 | ||
282 | bprm_clear_caps(bprm); | 372 | bprm_clear_caps(bprm); |
283 | 373 | ||
374 | if (!file_caps_enabled) | ||
375 | return 0; | ||
376 | |||
284 | if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) | 377 | if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) |
285 | return 0; | 378 | return 0; |
286 | 379 | ||
287 | dentry = dget(bprm->file->f_dentry); | 380 | dentry = dget(bprm->file->f_dentry); |
288 | inode = dentry->d_inode; | ||
289 | if (!inode->i_op || !inode->i_op->getxattr) | ||
290 | goto out; | ||
291 | 381 | ||
292 | rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &vcaps, | 382 | rc = get_vfs_caps_from_disk(dentry, &vcaps); |
293 | XATTR_CAPS_SZ); | 383 | if (rc < 0) { |
294 | if (rc == -ENODATA || rc == -EOPNOTSUPP) { | 384 | if (rc == -EINVAL) |
295 | /* no data, that's ok */ | 385 | printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n", |
296 | rc = 0; | 386 | __func__, rc, bprm->filename); |
387 | else if (rc == -ENODATA) | ||
388 | rc = 0; | ||
297 | goto out; | 389 | goto out; |
298 | } | 390 | } |
299 | if (rc < 0) | ||
300 | goto out; | ||
301 | 391 | ||
302 | rc = cap_from_disk(&vcaps, bprm, rc); | 392 | rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective); |
303 | if (rc == -EINVAL) | 393 | if (rc == -EINVAL) |
304 | printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", | 394 | printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", |
305 | __func__, rc, bprm->filename); | 395 | __func__, rc, bprm->filename); |
@@ -323,18 +413,57 @@ int cap_inode_killpriv(struct dentry *dentry) | |||
323 | return 0; | 413 | return 0; |
324 | } | 414 | } |
325 | 415 | ||
326 | static inline int get_file_caps(struct linux_binprm *bprm) | 416 | int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) |
417 | { | ||
418 | memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); | ||
419 | return -ENODATA; | ||
420 | } | ||
421 | |||
422 | static inline int get_file_caps(struct linux_binprm *bprm, bool *effective) | ||
327 | { | 423 | { |
328 | bprm_clear_caps(bprm); | 424 | bprm_clear_caps(bprm); |
329 | return 0; | 425 | return 0; |
330 | } | 426 | } |
331 | #endif | 427 | #endif |
332 | 428 | ||
333 | int cap_bprm_set_security (struct linux_binprm *bprm) | 429 | /* |
430 | * Determine whether a exec'ing process's new permitted capabilities should be | ||
431 | * limited to just what it already has. | ||
432 | * | ||
433 | * This prevents processes that are being ptraced from gaining access to | ||
434 | * CAP_SETPCAP, unless the process they're tracing already has it, and the | ||
435 | * binary they're executing has filecaps that elevate it. | ||
436 | * | ||
437 | * Returns 1 if they should be limited, 0 if they are not. | ||
438 | */ | ||
439 | static inline int cap_limit_ptraced_target(void) | ||
440 | { | ||
441 | #ifndef CONFIG_SECURITY_FILE_CAPABILITIES | ||
442 | if (capable(CAP_SETPCAP)) | ||
443 | return 0; | ||
444 | #endif | ||
445 | return 1; | ||
446 | } | ||
447 | |||
448 | /** | ||
449 | * cap_bprm_set_creds - Set up the proposed credentials for execve(). | ||
450 | * @bprm: The execution parameters, including the proposed creds | ||
451 | * | ||
452 | * Set up the proposed credentials for a new execution context being | ||
453 | * constructed by execve(). The proposed creds in @bprm->cred is altered, | ||
454 | * which won't take effect immediately. Returns 0 if successful, -ve on error. | ||
455 | */ | ||
456 | int cap_bprm_set_creds(struct linux_binprm *bprm) | ||
334 | { | 457 | { |
458 | const struct cred *old = current_cred(); | ||
459 | struct cred *new = bprm->cred; | ||
460 | bool effective; | ||
335 | int ret; | 461 | int ret; |
336 | 462 | ||
337 | ret = get_file_caps(bprm); | 463 | effective = false; |
464 | ret = get_file_caps(bprm, &effective); | ||
465 | if (ret < 0) | ||
466 | return ret; | ||
338 | 467 | ||
339 | if (!issecure(SECURE_NOROOT)) { | 468 | if (!issecure(SECURE_NOROOT)) { |
340 | /* | 469 | /* |
@@ -342,75 +471,113 @@ int cap_bprm_set_security (struct linux_binprm *bprm) | |||
342 | * executables under compatibility mode, we override the | 471 | * executables under compatibility mode, we override the |
343 | * capability sets for the file. | 472 | * capability sets for the file. |
344 | * | 473 | * |
345 | * If only the real uid is 0, we do not set the effective | 474 | * If only the real uid is 0, we do not set the effective bit. |
346 | * bit. | ||
347 | */ | 475 | */ |
348 | if (bprm->e_uid == 0 || current->uid == 0) { | 476 | if (new->euid == 0 || new->uid == 0) { |
349 | /* pP' = (cap_bset & ~0) | (pI & ~0) */ | 477 | /* pP' = (cap_bset & ~0) | (pI & ~0) */ |
350 | bprm->cap_post_exec_permitted = cap_combine( | 478 | new->cap_permitted = cap_combine(old->cap_bset, |
351 | current->cap_bset, current->cap_inheritable | 479 | old->cap_inheritable); |
352 | ); | ||
353 | bprm->cap_effective = (bprm->e_uid == 0); | ||
354 | ret = 0; | ||
355 | } | 480 | } |
481 | if (new->euid == 0) | ||
482 | effective = true; | ||
356 | } | 483 | } |
357 | 484 | ||
358 | return ret; | 485 | /* Don't let someone trace a set[ug]id/setpcap binary with the revised |
359 | } | 486 | * credentials unless they have the appropriate permit |
360 | 487 | */ | |
361 | void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) | 488 | if ((new->euid != old->uid || |
362 | { | 489 | new->egid != old->gid || |
363 | if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || | 490 | !cap_issubset(new->cap_permitted, old->cap_permitted)) && |
364 | !cap_issubset(bprm->cap_post_exec_permitted, | 491 | bprm->unsafe & ~LSM_UNSAFE_PTRACE_CAP) { |
365 | current->cap_permitted)) { | 492 | /* downgrade; they get no more than they had, and maybe less */ |
366 | set_dumpable(current->mm, suid_dumpable); | 493 | if (!capable(CAP_SETUID)) { |
367 | current->pdeath_signal = 0; | 494 | new->euid = new->uid; |
368 | 495 | new->egid = new->gid; | |
369 | if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { | ||
370 | if (!capable(CAP_SETUID)) { | ||
371 | bprm->e_uid = current->uid; | ||
372 | bprm->e_gid = current->gid; | ||
373 | } | ||
374 | if (cap_limit_ptraced_target()) { | ||
375 | bprm->cap_post_exec_permitted = cap_intersect( | ||
376 | bprm->cap_post_exec_permitted, | ||
377 | current->cap_permitted); | ||
378 | } | ||
379 | } | 496 | } |
497 | if (cap_limit_ptraced_target()) | ||
498 | new->cap_permitted = cap_intersect(new->cap_permitted, | ||
499 | old->cap_permitted); | ||
380 | } | 500 | } |
381 | 501 | ||
382 | current->suid = current->euid = current->fsuid = bprm->e_uid; | 502 | new->suid = new->fsuid = new->euid; |
383 | current->sgid = current->egid = current->fsgid = bprm->e_gid; | 503 | new->sgid = new->fsgid = new->egid; |
384 | 504 | ||
385 | /* For init, we want to retain the capabilities set | 505 | /* For init, we want to retain the capabilities set in the initial |
386 | * in the init_task struct. Thus we skip the usual | 506 | * task. Thus we skip the usual capability rules |
387 | * capability rules */ | 507 | */ |
388 | if (!is_global_init(current)) { | 508 | if (!is_global_init(current)) { |
389 | current->cap_permitted = bprm->cap_post_exec_permitted; | 509 | if (effective) |
390 | if (bprm->cap_effective) | 510 | new->cap_effective = new->cap_permitted; |
391 | current->cap_effective = bprm->cap_post_exec_permitted; | ||
392 | else | 511 | else |
393 | cap_clear(current->cap_effective); | 512 | cap_clear(new->cap_effective); |
394 | } | 513 | } |
514 | bprm->cap_effective = effective; | ||
395 | 515 | ||
396 | /* AUD: Audit candidate if current->cap_effective is set */ | 516 | /* |
517 | * Audit candidate if current->cap_effective is set | ||
518 | * | ||
519 | * We do not bother to audit if 3 things are true: | ||
520 | * 1) cap_effective has all caps | ||
521 | * 2) we are root | ||
522 | * 3) root is supposed to have all caps (SECURE_NOROOT) | ||
523 | * Since this is just a normal root execing a process. | ||
524 | * | ||
525 | * Number 1 above might fail if you don't have a full bset, but I think | ||
526 | * that is interesting information to audit. | ||
527 | */ | ||
528 | if (!cap_isclear(new->cap_effective)) { | ||
529 | if (!cap_issubset(CAP_FULL_SET, new->cap_effective) || | ||
530 | new->euid != 0 || new->uid != 0 || | ||
531 | issecure(SECURE_NOROOT)) { | ||
532 | ret = audit_log_bprm_fcaps(bprm, new, old); | ||
533 | if (ret < 0) | ||
534 | return ret; | ||
535 | } | ||
536 | } | ||
397 | 537 | ||
398 | current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); | 538 | new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); |
539 | return 0; | ||
399 | } | 540 | } |
400 | 541 | ||
401 | int cap_bprm_secureexec (struct linux_binprm *bprm) | 542 | /** |
543 | * cap_bprm_secureexec - Determine whether a secure execution is required | ||
544 | * @bprm: The execution parameters | ||
545 | * | ||
546 | * Determine whether a secure execution is required, return 1 if it is, and 0 | ||
547 | * if it is not. | ||
548 | * | ||
549 | * The credentials have been committed by this point, and so are no longer | ||
550 | * available through @bprm->cred. | ||
551 | */ | ||
552 | int cap_bprm_secureexec(struct linux_binprm *bprm) | ||
402 | { | 553 | { |
403 | if (current->uid != 0) { | 554 | const struct cred *cred = current_cred(); |
555 | |||
556 | if (cred->uid != 0) { | ||
404 | if (bprm->cap_effective) | 557 | if (bprm->cap_effective) |
405 | return 1; | 558 | return 1; |
406 | if (!cap_isclear(bprm->cap_post_exec_permitted)) | 559 | if (!cap_isclear(cred->cap_permitted)) |
407 | return 1; | 560 | return 1; |
408 | } | 561 | } |
409 | 562 | ||
410 | return (current->euid != current->uid || | 563 | return (cred->euid != cred->uid || |
411 | current->egid != current->gid); | 564 | cred->egid != cred->gid); |
412 | } | 565 | } |
413 | 566 | ||
567 | /** | ||
568 | * cap_inode_setxattr - Determine whether an xattr may be altered | ||
569 | * @dentry: The inode/dentry being altered | ||
570 | * @name: The name of the xattr to be changed | ||
571 | * @value: The value that the xattr will be changed to | ||
572 | * @size: The size of value | ||
573 | * @flags: The replacement flag | ||
574 | * | ||
575 | * Determine whether an xattr may be altered or set on an inode, returning 0 if | ||
576 | * permission is granted, -ve if denied. | ||
577 | * | ||
578 | * This is used to make sure security xattrs don't get updated or set by those | ||
579 | * who aren't privileged to do so. | ||
580 | */ | ||
414 | int cap_inode_setxattr(struct dentry *dentry, const char *name, | 581 | int cap_inode_setxattr(struct dentry *dentry, const char *name, |
415 | const void *value, size_t size, int flags) | 582 | const void *value, size_t size, int flags) |
416 | { | 583 | { |
@@ -418,28 +585,42 @@ int cap_inode_setxattr(struct dentry *dentry, const char *name, | |||
418 | if (!capable(CAP_SETFCAP)) | 585 | if (!capable(CAP_SETFCAP)) |
419 | return -EPERM; | 586 | return -EPERM; |
420 | return 0; | 587 | return 0; |
421 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | 588 | } |
589 | |||
590 | if (!strncmp(name, XATTR_SECURITY_PREFIX, | ||
422 | sizeof(XATTR_SECURITY_PREFIX) - 1) && | 591 | sizeof(XATTR_SECURITY_PREFIX) - 1) && |
423 | !capable(CAP_SYS_ADMIN)) | 592 | !capable(CAP_SYS_ADMIN)) |
424 | return -EPERM; | 593 | return -EPERM; |
425 | return 0; | 594 | return 0; |
426 | } | 595 | } |
427 | 596 | ||
597 | /** | ||
598 | * cap_inode_removexattr - Determine whether an xattr may be removed | ||
599 | * @dentry: The inode/dentry being altered | ||
600 | * @name: The name of the xattr to be changed | ||
601 | * | ||
602 | * Determine whether an xattr may be removed from an inode, returning 0 if | ||
603 | * permission is granted, -ve if denied. | ||
604 | * | ||
605 | * This is used to make sure security xattrs don't get removed by those who | ||
606 | * aren't privileged to remove them. | ||
607 | */ | ||
428 | int cap_inode_removexattr(struct dentry *dentry, const char *name) | 608 | int cap_inode_removexattr(struct dentry *dentry, const char *name) |
429 | { | 609 | { |
430 | if (!strcmp(name, XATTR_NAME_CAPS)) { | 610 | if (!strcmp(name, XATTR_NAME_CAPS)) { |
431 | if (!capable(CAP_SETFCAP)) | 611 | if (!capable(CAP_SETFCAP)) |
432 | return -EPERM; | 612 | return -EPERM; |
433 | return 0; | 613 | return 0; |
434 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | 614 | } |
615 | |||
616 | if (!strncmp(name, XATTR_SECURITY_PREFIX, | ||
435 | sizeof(XATTR_SECURITY_PREFIX) - 1) && | 617 | sizeof(XATTR_SECURITY_PREFIX) - 1) && |
436 | !capable(CAP_SYS_ADMIN)) | 618 | !capable(CAP_SYS_ADMIN)) |
437 | return -EPERM; | 619 | return -EPERM; |
438 | return 0; | 620 | return 0; |
439 | } | 621 | } |
440 | 622 | ||
441 | /* moved from kernel/sys.c. */ | 623 | /* |
442 | /* | ||
443 | * cap_emulate_setxuid() fixes the effective / permitted capabilities of | 624 | * cap_emulate_setxuid() fixes the effective / permitted capabilities of |
444 | * a process after a call to setuid, setreuid, or setresuid. | 625 | * a process after a call to setuid, setreuid, or setresuid. |
445 | * | 626 | * |
@@ -453,10 +634,10 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name) | |||
453 | * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective | 634 | * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective |
454 | * capabilities are set to the permitted capabilities. | 635 | * capabilities are set to the permitted capabilities. |
455 | * | 636 | * |
456 | * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should | 637 | * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should |
457 | * never happen. | 638 | * never happen. |
458 | * | 639 | * |
459 | * -astor | 640 | * -astor |
460 | * | 641 | * |
461 | * cevans - New behaviour, Oct '99 | 642 | * cevans - New behaviour, Oct '99 |
462 | * A process may, via prctl(), elect to keep its capabilities when it | 643 | * A process may, via prctl(), elect to keep its capabilities when it |
@@ -468,61 +649,60 @@ int cap_inode_removexattr(struct dentry *dentry, const char *name) | |||
468 | * files.. | 649 | * files.. |
469 | * Thanks to Olaf Kirch and Peter Benie for spotting this. | 650 | * Thanks to Olaf Kirch and Peter Benie for spotting this. |
470 | */ | 651 | */ |
471 | static inline void cap_emulate_setxuid (int old_ruid, int old_euid, | 652 | static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) |
472 | int old_suid) | ||
473 | { | 653 | { |
474 | if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && | 654 | if ((old->uid == 0 || old->euid == 0 || old->suid == 0) && |
475 | (current->uid != 0 && current->euid != 0 && current->suid != 0) && | 655 | (new->uid != 0 && new->euid != 0 && new->suid != 0) && |
476 | !issecure(SECURE_KEEP_CAPS)) { | 656 | !issecure(SECURE_KEEP_CAPS)) { |
477 | cap_clear (current->cap_permitted); | 657 | cap_clear(new->cap_permitted); |
478 | cap_clear (current->cap_effective); | 658 | cap_clear(new->cap_effective); |
479 | } | ||
480 | if (old_euid == 0 && current->euid != 0) { | ||
481 | cap_clear (current->cap_effective); | ||
482 | } | ||
483 | if (old_euid != 0 && current->euid == 0) { | ||
484 | current->cap_effective = current->cap_permitted; | ||
485 | } | 659 | } |
660 | if (old->euid == 0 && new->euid != 0) | ||
661 | cap_clear(new->cap_effective); | ||
662 | if (old->euid != 0 && new->euid == 0) | ||
663 | new->cap_effective = new->cap_permitted; | ||
486 | } | 664 | } |
487 | 665 | ||
488 | int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, | 666 | /** |
489 | int flags) | 667 | * cap_task_fix_setuid - Fix up the results of setuid() call |
668 | * @new: The proposed credentials | ||
669 | * @old: The current task's current credentials | ||
670 | * @flags: Indications of what has changed | ||
671 | * | ||
672 | * Fix up the results of setuid() call before the credential changes are | ||
673 | * actually applied, returning 0 to grant the changes, -ve to deny them. | ||
674 | */ | ||
675 | int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) | ||
490 | { | 676 | { |
491 | switch (flags) { | 677 | switch (flags) { |
492 | case LSM_SETID_RE: | 678 | case LSM_SETID_RE: |
493 | case LSM_SETID_ID: | 679 | case LSM_SETID_ID: |
494 | case LSM_SETID_RES: | 680 | case LSM_SETID_RES: |
495 | /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */ | 681 | /* juggle the capabilities to follow [RES]UID changes unless |
496 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | 682 | * otherwise suppressed */ |
497 | cap_emulate_setxuid (old_ruid, old_euid, old_suid); | 683 | if (!issecure(SECURE_NO_SETUID_FIXUP)) |
498 | } | 684 | cap_emulate_setxuid(new, old); |
499 | break; | 685 | break; |
500 | case LSM_SETID_FS: | ||
501 | { | ||
502 | uid_t old_fsuid = old_ruid; | ||
503 | 686 | ||
504 | /* Copied from kernel/sys.c:setfsuid. */ | 687 | case LSM_SETID_FS: |
505 | 688 | /* juggle the capabilties to follow FSUID changes, unless | |
506 | /* | 689 | * otherwise suppressed |
507 | * FIXME - is fsuser used for all CAP_FS_MASK capabilities? | 690 | * |
508 | * if not, we might be a bit too harsh here. | 691 | * FIXME - is fsuser used for all CAP_FS_MASK capabilities? |
509 | */ | 692 | * if not, we might be a bit too harsh here. |
510 | 693 | */ | |
511 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | 694 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
512 | if (old_fsuid == 0 && current->fsuid != 0) { | 695 | if (old->fsuid == 0 && new->fsuid != 0) |
513 | current->cap_effective = | 696 | new->cap_effective = |
514 | cap_drop_fs_set( | 697 | cap_drop_fs_set(new->cap_effective); |
515 | current->cap_effective); | 698 | |
516 | } | 699 | if (old->fsuid != 0 && new->fsuid == 0) |
517 | if (old_fsuid != 0 && current->fsuid == 0) { | 700 | new->cap_effective = |
518 | current->cap_effective = | 701 | cap_raise_fs_set(new->cap_effective, |
519 | cap_raise_fs_set( | 702 | new->cap_permitted); |
520 | current->cap_effective, | ||
521 | current->cap_permitted); | ||
522 | } | ||
523 | } | ||
524 | break; | ||
525 | } | 703 | } |
704 | break; | ||
705 | |||
526 | default: | 706 | default: |
527 | return -EINVAL; | 707 | return -EINVAL; |
528 | } | 708 | } |
@@ -543,42 +723,71 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, | |||
543 | */ | 723 | */ |
544 | static int cap_safe_nice(struct task_struct *p) | 724 | static int cap_safe_nice(struct task_struct *p) |
545 | { | 725 | { |
546 | if (!cap_issubset(p->cap_permitted, current->cap_permitted) && | 726 | int is_subset; |
547 | !capable(CAP_SYS_NICE)) | 727 | |
728 | rcu_read_lock(); | ||
729 | is_subset = cap_issubset(__task_cred(p)->cap_permitted, | ||
730 | current_cred()->cap_permitted); | ||
731 | rcu_read_unlock(); | ||
732 | |||
733 | if (!is_subset && !capable(CAP_SYS_NICE)) | ||
548 | return -EPERM; | 734 | return -EPERM; |
549 | return 0; | 735 | return 0; |
550 | } | 736 | } |
551 | 737 | ||
552 | int cap_task_setscheduler (struct task_struct *p, int policy, | 738 | /** |
739 | * cap_task_setscheduler - Detemine if scheduler policy change is permitted | ||
740 | * @p: The task to affect | ||
741 | * @policy: The policy to effect | ||
742 | * @lp: The parameters to the scheduling policy | ||
743 | * | ||
744 | * Detemine if the requested scheduler policy change is permitted for the | ||
745 | * specified task, returning 0 if permission is granted, -ve if denied. | ||
746 | */ | ||
747 | int cap_task_setscheduler(struct task_struct *p, int policy, | ||
553 | struct sched_param *lp) | 748 | struct sched_param *lp) |
554 | { | 749 | { |
555 | return cap_safe_nice(p); | 750 | return cap_safe_nice(p); |
556 | } | 751 | } |
557 | 752 | ||
558 | int cap_task_setioprio (struct task_struct *p, int ioprio) | 753 | /** |
754 | * cap_task_ioprio - Detemine if I/O priority change is permitted | ||
755 | * @p: The task to affect | ||
756 | * @ioprio: The I/O priority to set | ||
757 | * | ||
758 | * Detemine if the requested I/O priority change is permitted for the specified | ||
759 | * task, returning 0 if permission is granted, -ve if denied. | ||
760 | */ | ||
761 | int cap_task_setioprio(struct task_struct *p, int ioprio) | ||
559 | { | 762 | { |
560 | return cap_safe_nice(p); | 763 | return cap_safe_nice(p); |
561 | } | 764 | } |
562 | 765 | ||
563 | int cap_task_setnice (struct task_struct *p, int nice) | 766 | /** |
767 | * cap_task_ioprio - Detemine if task priority change is permitted | ||
768 | * @p: The task to affect | ||
769 | * @nice: The nice value to set | ||
770 | * | ||
771 | * Detemine if the requested task priority change is permitted for the | ||
772 | * specified task, returning 0 if permission is granted, -ve if denied. | ||
773 | */ | ||
774 | int cap_task_setnice(struct task_struct *p, int nice) | ||
564 | { | 775 | { |
565 | return cap_safe_nice(p); | 776 | return cap_safe_nice(p); |
566 | } | 777 | } |
567 | 778 | ||
568 | /* | 779 | /* |
569 | * called from kernel/sys.c for prctl(PR_CABSET_DROP) | 780 | * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from |
570 | * done without task_capability_lock() because it introduces | 781 | * the current task's bounding set. Returns 0 on success, -ve on error. |
571 | * no new races - i.e. only another task doing capget() on | ||
572 | * this task could get inconsistent info. There can be no | ||
573 | * racing writer bc a task can only change its own caps. | ||
574 | */ | 782 | */ |
575 | static long cap_prctl_drop(unsigned long cap) | 783 | static long cap_prctl_drop(struct cred *new, unsigned long cap) |
576 | { | 784 | { |
577 | if (!capable(CAP_SETPCAP)) | 785 | if (!capable(CAP_SETPCAP)) |
578 | return -EPERM; | 786 | return -EPERM; |
579 | if (!cap_valid(cap)) | 787 | if (!cap_valid(cap)) |
580 | return -EINVAL; | 788 | return -EINVAL; |
581 | cap_lower(current->cap_bset, cap); | 789 | |
790 | cap_lower(new->cap_bset, cap); | ||
582 | return 0; | 791 | return 0; |
583 | } | 792 | } |
584 | 793 | ||
@@ -598,22 +807,42 @@ int cap_task_setnice (struct task_struct *p, int nice) | |||
598 | } | 807 | } |
599 | #endif | 808 | #endif |
600 | 809 | ||
810 | /** | ||
811 | * cap_task_prctl - Implement process control functions for this security module | ||
812 | * @option: The process control function requested | ||
813 | * @arg2, @arg3, @arg4, @arg5: The argument data for this function | ||
814 | * | ||
815 | * Allow process control functions (sys_prctl()) to alter capabilities; may | ||
816 | * also deny access to other functions not otherwise implemented here. | ||
817 | * | ||
818 | * Returns 0 or +ve on success, -ENOSYS if this function is not implemented | ||
819 | * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM | ||
820 | * modules will consider performing the function. | ||
821 | */ | ||
601 | int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, | 822 | int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, |
602 | unsigned long arg4, unsigned long arg5, long *rc_p) | 823 | unsigned long arg4, unsigned long arg5) |
603 | { | 824 | { |
825 | struct cred *new; | ||
604 | long error = 0; | 826 | long error = 0; |
605 | 827 | ||
828 | new = prepare_creds(); | ||
829 | if (!new) | ||
830 | return -ENOMEM; | ||
831 | |||
606 | switch (option) { | 832 | switch (option) { |
607 | case PR_CAPBSET_READ: | 833 | case PR_CAPBSET_READ: |
834 | error = -EINVAL; | ||
608 | if (!cap_valid(arg2)) | 835 | if (!cap_valid(arg2)) |
609 | error = -EINVAL; | 836 | goto error; |
610 | else | 837 | error = !!cap_raised(new->cap_bset, arg2); |
611 | error = !!cap_raised(current->cap_bset, arg2); | 838 | goto no_change; |
612 | break; | 839 | |
613 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | 840 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES |
614 | case PR_CAPBSET_DROP: | 841 | case PR_CAPBSET_DROP: |
615 | error = cap_prctl_drop(arg2); | 842 | error = cap_prctl_drop(new, arg2); |
616 | break; | 843 | if (error < 0) |
844 | goto error; | ||
845 | goto changed; | ||
617 | 846 | ||
618 | /* | 847 | /* |
619 | * The next four prctl's remain to assist with transitioning a | 848 | * The next four prctl's remain to assist with transitioning a |
@@ -635,12 +864,12 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, | |||
635 | * capability-based-privilege environment. | 864 | * capability-based-privilege environment. |
636 | */ | 865 | */ |
637 | case PR_SET_SECUREBITS: | 866 | case PR_SET_SECUREBITS: |
638 | if ((((current->securebits & SECURE_ALL_LOCKS) >> 1) | 867 | error = -EPERM; |
639 | & (current->securebits ^ arg2)) /*[1]*/ | 868 | if ((((new->securebits & SECURE_ALL_LOCKS) >> 1) |
640 | || ((current->securebits & SECURE_ALL_LOCKS | 869 | & (new->securebits ^ arg2)) /*[1]*/ |
641 | & ~arg2)) /*[2]*/ | 870 | || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ |
642 | || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ | 871 | || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ |
643 | || (cap_capable(current, CAP_SETPCAP) != 0)) { /*[4]*/ | 872 | || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/ |
644 | /* | 873 | /* |
645 | * [1] no changing of bits that are locked | 874 | * [1] no changing of bits that are locked |
646 | * [2] no unlocking of locks | 875 | * [2] no unlocking of locks |
@@ -648,65 +877,80 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, | |||
648 | * [4] doing anything requires privilege (go read about | 877 | * [4] doing anything requires privilege (go read about |
649 | * the "sendmail capabilities bug") | 878 | * the "sendmail capabilities bug") |
650 | */ | 879 | */ |
651 | error = -EPERM; /* cannot change a locked bit */ | 880 | ) |
652 | } else { | 881 | /* cannot change a locked bit */ |
653 | current->securebits = arg2; | 882 | goto error; |
654 | } | 883 | new->securebits = arg2; |
655 | break; | 884 | goto changed; |
885 | |||
656 | case PR_GET_SECUREBITS: | 886 | case PR_GET_SECUREBITS: |
657 | error = current->securebits; | 887 | error = new->securebits; |
658 | break; | 888 | goto no_change; |
659 | 889 | ||
660 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | 890 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ |
661 | 891 | ||
662 | case PR_GET_KEEPCAPS: | 892 | case PR_GET_KEEPCAPS: |
663 | if (issecure(SECURE_KEEP_CAPS)) | 893 | if (issecure(SECURE_KEEP_CAPS)) |
664 | error = 1; | 894 | error = 1; |
665 | break; | 895 | goto no_change; |
896 | |||
666 | case PR_SET_KEEPCAPS: | 897 | case PR_SET_KEEPCAPS: |
898 | error = -EINVAL; | ||
667 | if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ | 899 | if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ |
668 | error = -EINVAL; | 900 | goto error; |
669 | else if (issecure(SECURE_KEEP_CAPS_LOCKED)) | 901 | error = -EPERM; |
670 | error = -EPERM; | 902 | if (issecure(SECURE_KEEP_CAPS_LOCKED)) |
671 | else if (arg2) | 903 | goto error; |
672 | current->securebits |= issecure_mask(SECURE_KEEP_CAPS); | 904 | if (arg2) |
905 | new->securebits |= issecure_mask(SECURE_KEEP_CAPS); | ||
673 | else | 906 | else |
674 | current->securebits &= | 907 | new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); |
675 | ~issecure_mask(SECURE_KEEP_CAPS); | 908 | goto changed; |
676 | break; | ||
677 | 909 | ||
678 | default: | 910 | default: |
679 | /* No functionality available - continue with default */ | 911 | /* No functionality available - continue with default */ |
680 | return 0; | 912 | error = -ENOSYS; |
913 | goto error; | ||
681 | } | 914 | } |
682 | 915 | ||
683 | /* Functionality provided */ | 916 | /* Functionality provided */ |
684 | *rc_p = error; | 917 | changed: |
685 | return 1; | 918 | return commit_creds(new); |
686 | } | ||
687 | 919 | ||
688 | void cap_task_reparent_to_init (struct task_struct *p) | 920 | no_change: |
689 | { | 921 | error = 0; |
690 | cap_set_init_eff(p->cap_effective); | 922 | error: |
691 | cap_clear(p->cap_inheritable); | 923 | abort_creds(new); |
692 | cap_set_full(p->cap_permitted); | 924 | return error; |
693 | p->securebits = SECUREBITS_DEFAULT; | ||
694 | return; | ||
695 | } | 925 | } |
696 | 926 | ||
697 | int cap_syslog (int type) | 927 | /** |
928 | * cap_syslog - Determine whether syslog function is permitted | ||
929 | * @type: Function requested | ||
930 | * | ||
931 | * Determine whether the current process is permitted to use a particular | ||
932 | * syslog function, returning 0 if permission is granted, -ve if not. | ||
933 | */ | ||
934 | int cap_syslog(int type) | ||
698 | { | 935 | { |
699 | if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) | 936 | if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) |
700 | return -EPERM; | 937 | return -EPERM; |
701 | return 0; | 938 | return 0; |
702 | } | 939 | } |
703 | 940 | ||
941 | /** | ||
942 | * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted | ||
943 | * @mm: The VM space in which the new mapping is to be made | ||
944 | * @pages: The size of the mapping | ||
945 | * | ||
946 | * Determine whether the allocation of a new virtual mapping by the current | ||
947 | * task is permitted, returning 0 if permission is granted, -ve if not. | ||
948 | */ | ||
704 | int cap_vm_enough_memory(struct mm_struct *mm, long pages) | 949 | int cap_vm_enough_memory(struct mm_struct *mm, long pages) |
705 | { | 950 | { |
706 | int cap_sys_admin = 0; | 951 | int cap_sys_admin = 0; |
707 | 952 | ||
708 | if (cap_capable(current, CAP_SYS_ADMIN) == 0) | 953 | if (cap_capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0) |
709 | cap_sys_admin = 1; | 954 | cap_sys_admin = 1; |
710 | return __vm_enough_memory(mm, pages, cap_sys_admin); | 955 | return __vm_enough_memory(mm, pages, cap_sys_admin); |
711 | } | 956 | } |
712 | |||