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Diffstat (limited to 'security/integrity/ima/ima_main.c')
-rw-r--r--security/integrity/ima/ima_main.c92
1 files changed, 66 insertions, 26 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 06a70c5a2329..061425dd6400 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -85,10 +85,10 @@ static void ima_rdwr_violation_check(struct file *file,
struct integrity_iint_cache *iint,
int must_measure,
char **pathbuf,
- const char **pathname)
+ const char **pathname,
+ char *filename)
{
struct inode *inode = file_inode(file);
- char filename[NAME_MAX];
fmode_t mode = file->f_mode;
bool send_tomtou = false, send_writers = false;
@@ -97,10 +97,13 @@ static void ima_rdwr_violation_check(struct file *file,
if (!iint)
iint = integrity_iint_find(inode);
/* IMA_MEASURE is set from reader side */
- if (iint && (iint->flags & IMA_MEASURE))
+ if (iint && test_bit(IMA_MUST_MEASURE,
+ &iint->atomic_flags))
send_tomtou = true;
}
} else {
+ if (must_measure)
+ set_bit(IMA_MUST_MEASURE, &iint->atomic_flags);
if ((atomic_read(&inode->i_writecount) > 0) && must_measure)
send_writers = true;
}
@@ -122,22 +125,25 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint,
struct inode *inode, struct file *file)
{
fmode_t mode = file->f_mode;
+ bool update;
if (!(mode & FMODE_WRITE))
return;
- inode_lock(inode);
+ mutex_lock(&iint->mutex);
if (atomic_read(&inode->i_writecount) == 1) {
+ update = test_and_clear_bit(IMA_UPDATE_XATTR,
+ &iint->atomic_flags);
if (!IS_I_VERSION(inode) ||
inode_cmp_iversion(inode, iint->version) ||
(iint->flags & IMA_NEW_FILE)) {
iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE);
iint->measured_pcrs = 0;
- if (iint->flags & IMA_APPRAISE)
+ if (update)
ima_update_xattr(iint, file);
}
}
- inode_unlock(inode);
+ mutex_unlock(&iint->mutex);
}
/**
@@ -170,7 +176,7 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
char *pathbuf = NULL;
char filename[NAME_MAX];
const char *pathname = NULL;
- int rc = -ENOMEM, action, must_appraise;
+ int rc = 0, action, must_appraise = 0;
int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
struct evm_ima_xattr_data *xattr_value = NULL;
int xattr_len = 0;
@@ -201,17 +207,31 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
if (action) {
iint = integrity_inode_get(inode);
if (!iint)
- goto out;
+ rc = -ENOMEM;
}
- if (violation_check) {
+ if (!rc && violation_check)
ima_rdwr_violation_check(file, iint, action & IMA_MEASURE,
- &pathbuf, &pathname);
- if (!action) {
- rc = 0;
- goto out_free;
- }
- }
+ &pathbuf, &pathname, filename);
+
+ inode_unlock(inode);
+
+ if (rc)
+ goto out;
+ if (!action)
+ goto out;
+
+ mutex_lock(&iint->mutex);
+
+ if (test_and_clear_bit(IMA_CHANGE_ATTR, &iint->atomic_flags))
+ /* reset appraisal flags if ima_inode_post_setattr was called */
+ iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED |
+ IMA_APPRAISE_SUBMASK | IMA_APPRAISED_SUBMASK |
+ IMA_ACTION_FLAGS);
+
+ if (test_and_clear_bit(IMA_CHANGE_XATTR, &iint->atomic_flags))
+ /* reset all flags if ima_inode_setxattr was called */
+ iint->flags &= ~IMA_DONE_MASK;
/* Determine if already appraised/measured based on bitmask
* (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
@@ -225,11 +245,23 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr)))
action ^= IMA_MEASURE;
+ /* HASH sets the digital signature and update flags, nothing else */
+ if ((action & IMA_HASH) &&
+ !(test_bit(IMA_DIGSIG, &iint->atomic_flags))) {
+ xattr_len = ima_read_xattr(file_dentry(file), &xattr_value);
+ if ((xattr_value && xattr_len > 2) &&
+ (xattr_value->type == EVM_IMA_XATTR_DIGSIG))
+ set_bit(IMA_DIGSIG, &iint->atomic_flags);
+ iint->flags |= IMA_HASHED;
+ action ^= IMA_HASH;
+ set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
+ }
+
/* Nothing to do, just return existing appraised status */
if (!action) {
if (must_appraise)
rc = ima_get_cache_status(iint, func);
- goto out_digsig;
+ goto out_locked;
}
template_desc = ima_template_desc_current();
@@ -242,7 +274,7 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
rc = ima_collect_measurement(iint, file, buf, size, hash_algo);
if (rc != 0 && rc != -EBADF && rc != -EINVAL)
- goto out_digsig;
+ goto out_locked;
if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */
pathname = ima_d_path(&file->f_path, &pathbuf, filename);
@@ -250,26 +282,32 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
if (action & IMA_MEASURE)
ima_store_measurement(iint, file, pathname,
xattr_value, xattr_len, pcr);
- if (rc == 0 && (action & IMA_APPRAISE_SUBMASK))
+ if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) {
+ inode_lock(inode);
rc = ima_appraise_measurement(func, iint, file, pathname,
xattr_value, xattr_len, opened);
+ inode_unlock(inode);
+ }
if (action & IMA_AUDIT)
ima_audit_measurement(iint, pathname);
if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO))
rc = 0;
-out_digsig:
- if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG) &&
+out_locked:
+ if ((mask & MAY_WRITE) && test_bit(IMA_DIGSIG, &iint->atomic_flags) &&
!(iint->flags & IMA_NEW_FILE))
rc = -EACCES;
+ mutex_unlock(&iint->mutex);
kfree(xattr_value);
-out_free:
+out:
if (pathbuf)
__putname(pathbuf);
-out:
- inode_unlock(inode);
- if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE))
- return -EACCES;
+ if (must_appraise) {
+ if (rc && (ima_appraise & IMA_APPRAISE_ENFORCE))
+ return -EACCES;
+ if (file->f_mode & FMODE_WRITE)
+ set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags);
+ }
return 0;
}
@@ -368,8 +406,10 @@ int ima_read_file(struct file *file, enum kernel_read_file_id read_id)
if (!file && read_id == READING_MODULE) {
if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES) &&
- (ima_appraise & IMA_APPRAISE_ENFORCE))
+ (ima_appraise & IMA_APPRAISE_ENFORCE)) {
+ pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n");
return -EACCES; /* INTEGRITY_UNKNOWN */
+ }
return 0; /* We rely on module signature checking */
}
return 0;
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 15:43:50 +0000