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 Signed-off-by: Tycho Andersen <tycho@xxxxxxxx> --- security/integrity/ima/ima.h | 4 ++-- security/integrity/ima/ima_api.c | 31 +++++++++++++++++++++++-------- security/integrity/ima/ima_main.c | 7 +++++-- 3 files changed, 30 insertions(+), 12 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index d52b487ad259..8e2470f72f7f 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -201,8 +201,8 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct evm_ima_xattr_data *xattr_value, int xattr_len, int pcr); -void ima_audit_measurement(struct integrity_iint_cache *iint, - const unsigned char *filename); +int ima_audit_measurement(struct integrity_iint_cache *iint, + const unsigned char *filename); int ima_alloc_init_template(struct ima_event_data *event_data, struct ima_template_entry **entry); int ima_store_template(struct ima_template_entry *entry, int violation, diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 08fe405338e1..008d3887ae00 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -304,17 +304,28 @@ void ima_store_measurement(struct integrity_iint_cache *iint, ima_free_template_entry(entry); } -void ima_audit_measurement(struct integrity_iint_cache *iint, - const unsigned char *filename) +int 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, *algo_hash; const char *algo_name = hash_algo_name[iint->ima_hash->algo]; - char algo_hash[sizeof(hash) + strlen(algo_name) + 2]; - int i; + int i, hash_len, algo_hash_len; if (iint->flags & IMA_AUDITED) - return; + return 0; + + hash_len = (iint->ima_hash->length * 2) + 1; + hash = kzalloc(hash_len, GFP_KERNEL); + if (!hash) + return -ENOMEM; + + algo_hash_len = hash_len + strlen(algo_name) + 2; + algo_hash = kzalloc(algo_hash_len, GFP_KERNEL); + if (!algo_hash) { + kfree(hash); + return -ENOMEM; + } for (i = 0; i < iint->ima_hash->length; i++) hex_byte_pack(hash + (i * 2), iint->ima_hash->digest[i]); @@ -323,18 +334,22 @@ 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); + snprintf(algo_hash, algo_hash_len, "%s:%s", algo_name, hash); audit_log_untrustedstring(ab, algo_hash); audit_log_task_info(ab, current); audit_log_end(ab); iint->flags |= IMA_AUDITED; +out: + kfree(hash); + kfree(algo_hash); + return 0; } /* diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 2cfb0c714967..356faae6f09c 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -288,8 +288,11 @@ static int process_measurement(struct file *file, char *buf, loff_t size, xattr_value, xattr_len, opened); inode_unlock(inode); } - if (action & IMA_AUDIT) - ima_audit_measurement(iint, pathname); + if (action & IMA_AUDIT) { + rc = ima_audit_measurement(iint, pathname); + if (rc < 0) + goto out_locked; + } if ((file->f_flags & O_DIRECT) && (iint->flags & IMA_PERMIT_DIRECTIO)) rc = 0; -- 2.14.1
