[PATCH v3] ima: drop vla in ima_audit_measurement()
From: Tycho Andersen <hidden>
Date: 2018-03-08 23:08:36
Also in:
lkml
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), security subsystem, the rest · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
In keeping with the directive to get rid of VLAs [1], let's drop the VLA from ima_audit_measurement(). We need to adjust the return type of ima_audit_measurement, because now this function can fail if an allocation fails. [1]: https://lkml.org/lkml/2018/3/7/621 v2: just use audit_log_format instead of doing a second allocation v3: ignore failures in ima_audit_measurement() Signed-off-by: Tycho Andersen <redacted> --- security/integrity/ima/ima_api.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 08fe405338e1..2aab9170ef68 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c@@ -308,14 +308,17 @@ void ima_audit_measurement(struct integrity_iint_cache *iint, const unsigned char *filename) { struct audit_buffer *ab; - char hash[(iint->ima_hash->length * 2) + 1]; + char *hash; const char *algo_name = hash_algo_name[iint->ima_hash->algo]; - char algo_hash[sizeof(hash) + strlen(algo_name) + 2]; int i; if (iint->flags & IMA_AUDITED) return; + hash = kzalloc((iint->ima_hash->length * 2) + 1, GFP_KERNEL); + if (!hash) + return; + for (i = 0; i < iint->ima_hash->length; i++) hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]); hash[i * 2] = '\0';
@@ -323,18 +326,19 @@ void ima_audit_measurement(struct integrity_iint_cache *iint, ab = audit_log_start(current->audit_context, GFP_KERNEL, AUDIT_INTEGRITY_RULE); if (!ab) - return; + goto out; audit_log_format(ab, "file="); audit_log_untrustedstring(ab, filename); - audit_log_format(ab, " hash="); - snprintf(algo_hash, sizeof(algo_hash), "%s:%s", algo_name, hash); - audit_log_untrustedstring(ab, algo_hash); + audit_log_format(ab, " hash=\"%s:%s\"", algo_name, hash); audit_log_task_info(ab, current); audit_log_end(ab); iint->flags |= IMA_AUDITED; +out: + kfree(hash); + return; } /*
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2.14.1