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| author | Roberto Sassu <roberto.sassu@huawei.com> | 2021-07-23 11:53:02 +0300 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.ibm.com> | 2021-07-23 16:25:28 +0300 |
| commit | 5d1ef2ce13a9098b4e0d31c50e4c79763a57b444 (patch) | |
| tree | 1415f5cd4b9ff5546c5e6c0c9fdfc897c2bd797e /security | |
| parent | a32ad90426a9c8eb3915eed26e08ce133bd9e0da (diff) | |
| download | linux-5d1ef2ce13a9098b4e0d31c50e4c79763a57b444.tar.xz | |
ima: Introduce ima_get_current_hash_algo()
Buffer measurements, unlike file measurements, are not accessible after the
measurement is done, as buffers are not suitable for use with the
integrity_iint_cache structure (there is no index, for files it is the
inode number). In the subsequent patches, the measurement (digest) will be
returned directly by the functions that perform the buffer measurement,
ima_measure_critical_data() and process_buffer_measurement().
A caller of those functions also needs to know the algorithm used to
calculate the digest. Instead of adding the algorithm as a new parameter to
the functions, this patch provides it separately with the new function
ima_get_current_hash_algo().
Since the hash algorithm does not change after the IMA setup phase, there
is no risk of races (obtaining a digest calculated with a different
algorithm than the one returned).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
[zohar@linux.ibm.com: annotate ima_hash_algo as __ro_after_init]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/ima/ima_main.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 287b90509006..634e4709d8af 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -35,7 +35,7 @@ int ima_appraise = IMA_APPRAISE_ENFORCE; int ima_appraise; #endif -int ima_hash_algo = HASH_ALGO_SHA1; +int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1; static int hash_setup_done; static struct notifier_block ima_lsm_policy_notifier = { @@ -76,6 +76,11 @@ out: } __setup("ima_hash=", hash_setup); +enum hash_algo ima_get_current_hash_algo(void) +{ + return ima_hash_algo; +} + /* Prevent mmap'ing a file execute that is already mmap'ed write */ static int mmap_violation_check(enum ima_hooks func, struct file *file, char **pathbuf, const char **pathname, |