diff options
| -rw-r--r-- | fs/namei.c | 6 | ||||
| -rw-r--r-- | fs/nfsd/vfs.c | 3 | ||||
| -rw-r--r-- | include/linux/ima.h | 4 | ||||
| -rw-r--r-- | security/integrity/ima/ima_main.c | 236 |
4 files changed, 97 insertions, 152 deletions
diff --git a/fs/namei.c b/fs/namei.c index 94a5e60779f9..cd77b6375efd 100644 --- a/fs/namei.c +++ b/fs/namei.c | |||
| @@ -1736,8 +1736,7 @@ do_last: | |||
| 1736 | if (nd.root.mnt) | 1736 | if (nd.root.mnt) |
| 1737 | path_put(&nd.root); | 1737 | path_put(&nd.root); |
| 1738 | if (!IS_ERR(filp)) { | 1738 | if (!IS_ERR(filp)) { |
| 1739 | error = ima_path_check(&filp->f_path, filp->f_mode & | 1739 | error = ima_path_check(filp, acc_mode); |
| 1740 | (MAY_READ | MAY_WRITE | MAY_EXEC)); | ||
| 1741 | if (error) { | 1740 | if (error) { |
| 1742 | fput(filp); | 1741 | fput(filp); |
| 1743 | filp = ERR_PTR(error); | 1742 | filp = ERR_PTR(error); |
| @@ -1797,8 +1796,7 @@ ok: | |||
| 1797 | } | 1796 | } |
| 1798 | filp = nameidata_to_filp(&nd); | 1797 | filp = nameidata_to_filp(&nd); |
| 1799 | if (!IS_ERR(filp)) { | 1798 | if (!IS_ERR(filp)) { |
| 1800 | error = ima_path_check(&filp->f_path, filp->f_mode & | 1799 | error = ima_path_check(filp, acc_mode); |
| 1801 | (MAY_READ | MAY_WRITE | MAY_EXEC)); | ||
| 1802 | if (error) { | 1800 | if (error) { |
| 1803 | fput(filp); | 1801 | fput(filp); |
| 1804 | filp = ERR_PTR(error); | 1802 | filp = ERR_PTR(error); |
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 325959e264ce..32477e3a645c 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c | |||
| @@ -752,8 +752,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, | |||
| 752 | flags, current_cred()); | 752 | flags, current_cred()); |
| 753 | if (IS_ERR(*filp)) | 753 | if (IS_ERR(*filp)) |
| 754 | host_err = PTR_ERR(*filp); | 754 | host_err = PTR_ERR(*filp); |
| 755 | host_err = ima_path_check(&(*filp)->f_path, | 755 | host_err = ima_path_check(*filp, access); |
| 756 | access & (MAY_READ | MAY_WRITE | MAY_EXEC)); | ||
| 757 | out_nfserr: | 756 | out_nfserr: |
| 758 | err = nfserrno(host_err); | 757 | err = nfserrno(host_err); |
| 759 | out: | 758 | out: |
diff --git a/include/linux/ima.h b/include/linux/ima.h index 99dc6d5cf7e5..aa55a8f1f5b9 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h | |||
| @@ -17,7 +17,7 @@ struct linux_binprm; | |||
| 17 | extern int ima_bprm_check(struct linux_binprm *bprm); | 17 | extern int ima_bprm_check(struct linux_binprm *bprm); |
| 18 | extern int ima_inode_alloc(struct inode *inode); | 18 | extern int ima_inode_alloc(struct inode *inode); |
| 19 | extern void ima_inode_free(struct inode *inode); | 19 | extern void ima_inode_free(struct inode *inode); |
| 20 | extern int ima_path_check(struct path *path, int mask); | 20 | extern int ima_path_check(struct file *file, int mask); |
| 21 | extern void ima_file_free(struct file *file); | 21 | extern void ima_file_free(struct file *file); |
| 22 | extern int ima_file_mmap(struct file *file, unsigned long prot); | 22 | extern int ima_file_mmap(struct file *file, unsigned long prot); |
| 23 | extern void ima_counts_get(struct file *file); | 23 | extern void ima_counts_get(struct file *file); |
| @@ -38,7 +38,7 @@ static inline void ima_inode_free(struct inode *inode) | |||
| 38 | return; | 38 | return; |
| 39 | } | 39 | } |
| 40 | 40 | ||
| 41 | static inline int ima_path_check(struct path *path, int mask) | 41 | static inline int ima_path_check(struct file *file, int mask) |
| 42 | { | 42 | { |
| 43 | return 0; | 43 | return 0; |
| 44 | } | 44 | } |
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index a89f44d5e030..75aee18f6163 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c | |||
| @@ -84,6 +84,36 @@ out: | |||
| 84 | return found; | 84 | return found; |
| 85 | } | 85 | } |
| 86 | 86 | ||
| 87 | /* ima_read_write_check - reflect possible reading/writing errors in the PCR. | ||
| 88 | * | ||
| 89 | * When opening a file for read, if the file is already open for write, | ||
| 90 | * the file could change, resulting in a file measurement error. | ||
| 91 | * | ||
| 92 | * Opening a file for write, if the file is already open for read, results | ||
| 93 | * in a time of measure, time of use (ToMToU) error. | ||
| 94 | * | ||
| 95 | * In either case invalidate the PCR. | ||
| 96 | */ | ||
| 97 | enum iint_pcr_error { TOMTOU, OPEN_WRITERS }; | ||
| 98 | static void ima_read_write_check(enum iint_pcr_error error, | ||
| 99 | struct ima_iint_cache *iint, | ||
| 100 | struct inode *inode, | ||
| 101 | const unsigned char *filename) | ||
| 102 | { | ||
| 103 | switch (error) { | ||
| 104 | case TOMTOU: | ||
| 105 | if (iint->readcount > 0) | ||
| 106 | ima_add_violation(inode, filename, "invalid_pcr", | ||
| 107 | "ToMToU"); | ||
| 108 | break; | ||
| 109 | case OPEN_WRITERS: | ||
| 110 | if (iint->writecount > 0) | ||
| 111 | ima_add_violation(inode, filename, "invalid_pcr", | ||
| 112 | "open_writers"); | ||
| 113 | break; | ||
| 114 | } | ||
| 115 | } | ||
| 116 | |||
| 87 | /* | 117 | /* |
| 88 | * Update the counts given an fmode_t | 118 | * Update the counts given an fmode_t |
| 89 | */ | 119 | */ |
| @@ -99,6 +129,47 @@ static void ima_inc_counts(struct ima_iint_cache *iint, fmode_t mode) | |||
| 99 | } | 129 | } |
| 100 | 130 | ||
| 101 | /* | 131 | /* |
| 132 | * ima_counts_get - increment file counts | ||
| 133 | * | ||
| 134 | * Maintain read/write counters for all files, but only | ||
| 135 | * invalidate the PCR for measured files: | ||
| 136 | * - Opening a file for write when already open for read, | ||
| 137 | * results in a time of measure, time of use (ToMToU) error. | ||
| 138 | * - Opening a file for read when already open for write, | ||
| 139 | * could result in a file measurement error. | ||
| 140 | * | ||
| 141 | */ | ||
| 142 | void ima_counts_get(struct file *file) | ||
| 143 | { | ||
| 144 | struct dentry *dentry = file->f_path.dentry; | ||
| 145 | struct inode *inode = dentry->d_inode; | ||
| 146 | fmode_t mode = file->f_mode; | ||
| 147 | struct ima_iint_cache *iint; | ||
| 148 | int rc; | ||
| 149 | |||
| 150 | if (!ima_initialized || !S_ISREG(inode->i_mode)) | ||
| 151 | return; | ||
| 152 | iint = ima_iint_find_get(inode); | ||
| 153 | if (!iint) | ||
| 154 | return; | ||
| 155 | mutex_lock(&iint->mutex); | ||
| 156 | rc = ima_must_measure(iint, inode, MAY_READ, PATH_CHECK); | ||
| 157 | if (rc < 0) | ||
| 158 | goto out; | ||
| 159 | |||
| 160 | if (mode & FMODE_WRITE) { | ||
| 161 | ima_read_write_check(TOMTOU, iint, inode, dentry->d_name.name); | ||
| 162 | goto out; | ||
| 163 | } | ||
| 164 | ima_read_write_check(OPEN_WRITERS, iint, inode, dentry->d_name.name); | ||
| 165 | out: | ||
| 166 | ima_inc_counts(iint, file->f_mode); | ||
| 167 | mutex_unlock(&iint->mutex); | ||
| 168 | |||
| 169 | kref_put(&iint->refcount, iint_free); | ||
| 170 | } | ||
| 171 | |||
| 172 | /* | ||
| 102 | * Decrement ima counts | 173 | * Decrement ima counts |
| 103 | */ | 174 | */ |
| 104 | static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode, | 175 | static void ima_dec_counts(struct ima_iint_cache *iint, struct inode *inode, |
| @@ -153,123 +224,6 @@ void ima_file_free(struct file *file) | |||
| 153 | kref_put(&iint->refcount, iint_free); | 224 | kref_put(&iint->refcount, iint_free); |
| 154 | } | 225 | } |
| 155 | 226 | ||
| 156 | /* ima_read_write_check - reflect possible reading/writing errors in the PCR. | ||
| 157 | * | ||
| 158 | * When opening a file for read, if the file is already open for write, | ||
| 159 | * the file could change, resulting in a file measurement error. | ||
| 160 | * | ||
| 161 | * Opening a file for write, if the file is already open for read, results | ||
| 162 | * in a time of measure, time of use (ToMToU) error. | ||
| 163 | * | ||
| 164 | * In either case invalidate the PCR. | ||
| 165 | */ | ||
| 166 | enum iint_pcr_error { TOMTOU, OPEN_WRITERS }; | ||
| 167 | static void ima_read_write_check(enum iint_pcr_error error, | ||
| 168 | struct ima_iint_cache *iint, | ||
| 169 | struct inode *inode, | ||
| 170 | const unsigned char *filename) | ||
| 171 | { | ||
| 172 | switch (error) { | ||
| 173 | case TOMTOU: | ||
| 174 | if (iint->readcount > 0) | ||
| 175 | ima_add_violation(inode, filename, "invalid_pcr", | ||
| 176 | "ToMToU"); | ||
| 177 | break; | ||
| 178 | case OPEN_WRITERS: | ||
| 179 | if (iint->writecount > 0) | ||
| 180 | ima_add_violation(inode, filename, "invalid_pcr", | ||
| 181 | "open_writers"); | ||
| 182 | break; | ||
| 183 | } | ||
| 184 | } | ||
| 185 | |||
| 186 | static int get_path_measurement(struct ima_iint_cache *iint, struct file *file, | ||
| 187 | const unsigned char *filename) | ||
| 188 | { | ||
| 189 | int rc = 0; | ||
| 190 | |||
| 191 | ima_inc_counts(iint, file->f_mode); | ||
| 192 | |||
| 193 | rc = ima_collect_measurement(iint, file); | ||
| 194 | if (!rc) | ||
| 195 | ima_store_measurement(iint, file, filename); | ||
| 196 | return rc; | ||
| 197 | } | ||
| 198 | |||
| 199 | /** | ||
| 200 | * ima_path_check - based on policy, collect/store measurement. | ||
| 201 | * @path: contains a pointer to the path to be measured | ||
| 202 | * @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE | ||
| 203 | * | ||
| 204 | * Measure the file being open for readonly, based on the | ||
| 205 | * ima_must_measure() policy decision. | ||
| 206 | * | ||
| 207 | * Keep read/write counters for all files, but only | ||
| 208 | * invalidate the PCR for measured files: | ||
| 209 | * - Opening a file for write when already open for read, | ||
| 210 | * results in a time of measure, time of use (ToMToU) error. | ||
| 211 | * - Opening a file for read when already open for write, | ||
| 212 | * could result in a file measurement error. | ||
| 213 | * | ||
| 214 | * Always return 0 and audit dentry_open failures. | ||
| 215 | * (Return code will be based upon measurement appraisal.) | ||
| 216 | */ | ||
| 217 | int ima_path_check(struct path *path, int mask) | ||
| 218 | { | ||
| 219 | struct inode *inode = path->dentry->d_inode; | ||
| 220 | struct ima_iint_cache *iint; | ||
| 221 | struct file *file = NULL; | ||
| 222 | int rc; | ||
| 223 | |||
| 224 | if (!ima_initialized || !S_ISREG(inode->i_mode)) | ||
| 225 | return 0; | ||
| 226 | iint = ima_iint_find_get(inode); | ||
| 227 | if (!iint) | ||
| 228 | return 0; | ||
| 229 | |||
| 230 | mutex_lock(&iint->mutex); | ||
| 231 | |||
| 232 | rc = ima_must_measure(iint, inode, MAY_READ, PATH_CHECK); | ||
| 233 | if (rc < 0) | ||
| 234 | goto out; | ||
| 235 | |||
| 236 | if ((mask & MAY_WRITE) || (mask == 0)) | ||
| 237 | ima_read_write_check(TOMTOU, iint, inode, | ||
| 238 | path->dentry->d_name.name); | ||
| 239 | |||
| 240 | if ((mask & (MAY_WRITE | MAY_READ | MAY_EXEC)) != MAY_READ) | ||
| 241 | goto out; | ||
| 242 | |||
| 243 | ima_read_write_check(OPEN_WRITERS, iint, inode, | ||
| 244 | path->dentry->d_name.name); | ||
| 245 | if (!(iint->flags & IMA_MEASURED)) { | ||
| 246 | struct dentry *dentry = dget(path->dentry); | ||
| 247 | struct vfsmount *mnt = mntget(path->mnt); | ||
| 248 | |||
| 249 | file = dentry_open(dentry, mnt, O_RDONLY | O_LARGEFILE, | ||
| 250 | current_cred()); | ||
| 251 | if (IS_ERR(file)) { | ||
| 252 | int audit_info = 0; | ||
| 253 | |||
| 254 | integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, | ||
| 255 | dentry->d_name.name, | ||
| 256 | "add_measurement", | ||
| 257 | "dentry_open failed", | ||
| 258 | 1, audit_info); | ||
| 259 | file = NULL; | ||
| 260 | goto out; | ||
| 261 | } | ||
| 262 | rc = get_path_measurement(iint, file, dentry->d_name.name); | ||
| 263 | } | ||
| 264 | out: | ||
| 265 | mutex_unlock(&iint->mutex); | ||
| 266 | if (file) | ||
| 267 | fput(file); | ||
| 268 | kref_put(&iint->refcount, iint_free); | ||
| 269 | return 0; | ||
| 270 | } | ||
| 271 | EXPORT_SYMBOL_GPL(ima_path_check); | ||
| 272 | |||
| 273 | static int process_measurement(struct file *file, const unsigned char *filename, | 227 | static int process_measurement(struct file *file, const unsigned char *filename, |
| 274 | int mask, int function) | 228 | int mask, int function) |
| 275 | { | 229 | { |
| @@ -297,33 +251,6 @@ out: | |||
| 297 | return rc; | 251 | return rc; |
| 298 | } | 252 | } |
| 299 | 253 | ||
| 300 | /* | ||
| 301 | * ima_counts_get - increment file counts | ||
| 302 | * | ||
| 303 | * - for IPC shm and shmat file. | ||
| 304 | * - for nfsd exported files. | ||
| 305 | * | ||
| 306 | * Increment the counts for these files to prevent unnecessary | ||
| 307 | * imbalance messages. | ||
| 308 | */ | ||
| 309 | void ima_counts_get(struct file *file) | ||
| 310 | { | ||
| 311 | struct inode *inode = file->f_dentry->d_inode; | ||
| 312 | struct ima_iint_cache *iint; | ||
| 313 | |||
| 314 | if (!ima_initialized || !S_ISREG(inode->i_mode)) | ||
| 315 | return; | ||
| 316 | iint = ima_iint_find_get(inode); | ||
| 317 | if (!iint) | ||
| 318 | return; | ||
| 319 | mutex_lock(&iint->mutex); | ||
| 320 | ima_inc_counts(iint, file->f_mode); | ||
| 321 | mutex_unlock(&iint->mutex); | ||
| 322 | |||
| 323 | kref_put(&iint->refcount, iint_free); | ||
| 324 | } | ||
| 325 | EXPORT_SYMBOL_GPL(ima_counts_get); | ||
| 326 | |||
| 327 | /** | 254 | /** |
| 328 | * ima_file_mmap - based on policy, collect/store measurement. | 255 | * ima_file_mmap - based on policy, collect/store measurement. |
| 329 | * @file: pointer to the file to be measured (May be NULL) | 256 | * @file: pointer to the file to be measured (May be NULL) |
| @@ -369,6 +296,27 @@ int ima_bprm_check(struct linux_binprm *bprm) | |||
| 369 | return 0; | 296 | return 0; |
| 370 | } | 297 | } |
| 371 | 298 | ||
| 299 | /** | ||
| 300 | * ima_path_check - based on policy, collect/store measurement. | ||
| 301 | * @file: pointer to the file to be measured | ||
| 302 | * @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE | ||
| 303 | * | ||
| 304 | * Measure files based on the ima_must_measure() policy decision. | ||
| 305 | * | ||
| 306 | * Always return 0 and audit dentry_open failures. | ||
| 307 | * (Return code will be based upon measurement appraisal.) | ||
| 308 | */ | ||
| 309 | int ima_path_check(struct file *file, int mask) | ||
| 310 | { | ||
| 311 | int rc; | ||
| 312 | |||
| 313 | rc = process_measurement(file, file->f_dentry->d_name.name, | ||
| 314 | mask & (MAY_READ | MAY_WRITE | MAY_EXEC), | ||
| 315 | PATH_CHECK); | ||
| 316 | return 0; | ||
| 317 | } | ||
| 318 | EXPORT_SYMBOL_GPL(ima_path_check); | ||
| 319 | |||
| 372 | static int __init init_ima(void) | 320 | static int __init init_ima(void) |
| 373 | { | 321 | { |
| 374 | int error; | 322 | int error; |
