diff options
| author | Eric Richter <erichte@linux.vnet.ibm.com> | 2016-06-01 13:14:06 -0500 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.vnet.ibm.com> | 2016-06-30 01:14:22 -0400 |
| commit | a422638d492a35316e3fd9bb31bfc9769b249bca (patch) | |
| tree | ee3c83ca967003972763fb18de707bd7cc5bb58f /security/integrity/ima | |
| parent | 67696f6d79923cdc0084b73b4bbe52e6749a43a4 (diff) | |
ima: change integrity cache to store measured pcr
IMA avoids re-measuring files by storing the current state as a flag in
the integrity cache. It will then skip adding a new measurement log entry
if the cache reports the file as already measured.
If a policy measures an already measured file to a new PCR, the measurement
will not be added to the list. This patch implements a new bitfield for
specifying which PCR the file was measured into, rather than if it was
measured.
Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Diffstat (limited to 'security/integrity/ima')
| -rw-r--r-- | security/integrity/ima/ima_api.c | 6 | ||||
| -rw-r--r-- | security/integrity/ima/ima_appraise.c | 1 | ||||
| -rw-r--r-- | security/integrity/ima/ima_main.c | 7 |
3 files changed, 11 insertions, 3 deletions
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 8363ba384992..9df26a2b75ba 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -266,7 +266,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint, xattr_len, NULL}; int violation = 0; - if (iint->flags & IMA_MEASURED) + if (iint->measured_pcrs & (0x1 << pcr)) return; result = ima_alloc_init_template(&event_data, &entry); @@ -277,8 +277,10 @@ void ima_store_measurement(struct integrity_iint_cache *iint, } result = ima_store_template(entry, violation, inode, filename, pcr); - if (!result || result == -EEXIST) + if (!result || result == -EEXIST) { iint->flags |= IMA_MEASURED; + iint->measured_pcrs |= (0x1 << pcr); + } if (result < 0) ima_free_template_entry(entry); } diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index fe8e92360d77..4b9b4a4e1b89 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -370,6 +370,7 @@ static void ima_reset_appraise_flags(struct inode *inode, int digsig) return; iint->flags &= ~IMA_DONE_MASK; + iint->measured_pcrs = 0; if (digsig) iint->flags |= IMA_DIGSIG; return; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 3627afdc932e..596ef616ac21 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -125,6 +125,7 @@ static void ima_check_last_writer(struct integrity_iint_cache *iint, if ((iint->version != inode->i_version) || (iint->flags & IMA_NEW_FILE)) { iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE); + iint->measured_pcrs = 0; if (iint->flags & IMA_APPRAISE) ima_update_xattr(iint, file); } @@ -210,7 +211,11 @@ static int process_measurement(struct file *file, char *buf, loff_t size, */ iint->flags |= action; action &= IMA_DO_MASK; - action &= ~((iint->flags & IMA_DONE_MASK) >> 1); + action &= ~((iint->flags & (IMA_DONE_MASK ^ IMA_MEASURED)) >> 1); + + /* If target pcr is already measured, unset IMA_MEASURE action */ + if ((action & IMA_MEASURE) && (iint->measured_pcrs & (0x1 << pcr))) + action ^= IMA_MEASURE; /* Nothing to do, just return existing appraised status */ if (!action) { |