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ima: properly free ima_template_entry structures

The new templates management mechanism records information associated
to an event into an array of 'ima_field_data' structures and makes it
available through the 'template_data' field of the 'ima_template_entry'
structure (the element of the measurements list created by IMA).

Since 'ima_field_data' contains dynamically allocated data (which length
varies depending on the data associated to a selected template field),
it is not enough to just free the memory reserved for a
'ima_template_entry' structure if something goes wrong.

This patch creates the new function ima_free_template_entry() which
walks the array of 'ima_field_data' structures, frees the memory
referenced by the 'data' pointer and finally the space reserved for
the 'ima_template_entry' structure. Further, it replaces existing kfree()
that have a pointer to an 'ima_template_entry' structure as argument
with calls to the new function.

Fixes: a71dc65: ima: switch to new template management mechanism
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
master
Roberto Sassu 8 years ago
committed by Mimi Zohar
parent
commit
a7ed7c60e1
  1. 1
      security/integrity/ima/ima.h
  2. 21
      security/integrity/ima/ima_api.c
  3. 2
      security/integrity/ima/ima_init.c

1
security/integrity/ima/ima.h

@ -148,6 +148,7 @@ int ima_alloc_init_template(struct integrity_iint_cache *iint,
int xattr_len, struct ima_template_entry **entry);
int ima_store_template(struct ima_template_entry *entry, int violation,
struct inode *inode, const unsigned char *filename);
void ima_free_template_entry(struct ima_template_entry *entry);
const char *ima_d_path(struct path *path, char **pathbuf);
/* rbtree tree calls to lookup, insert, delete

21
security/integrity/ima/ima_api.c

@ -21,6 +21,19 @@
#include <crypto/hash_info.h>
#include "ima.h"
/*
* ima_free_template_entry - free an existing template entry
*/
void ima_free_template_entry(struct ima_template_entry *entry)
{
int i;
for (i = 0; i < entry->template_desc->num_fields; i++)
kfree(entry->template_data[i].data);
kfree(entry);
}
/*
* ima_alloc_init_template - create and initialize a new template entry
*/
@ -37,6 +50,7 @@ int ima_alloc_init_template(struct integrity_iint_cache *iint,
if (!*entry)
return -ENOMEM;
(*entry)->template_desc = template_desc;
for (i = 0; i < template_desc->num_fields; i++) {
struct ima_template_field *field = template_desc->fields[i];
u32 len;
@ -51,10 +65,9 @@ int ima_alloc_init_template(struct integrity_iint_cache *iint,
(*entry)->template_data_len += sizeof(len);
(*entry)->template_data_len += len;
}
(*entry)->template_desc = template_desc;
return 0;
out:
kfree(*entry);
ima_free_template_entry(*entry);
*entry = NULL;
return result;
}
@ -134,7 +147,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
}
result = ima_store_template(entry, violation, inode, filename);
if (result < 0)
kfree(entry);
ima_free_template_entry(entry);
err_out:
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
op, cause, result, 0);
@ -269,7 +282,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
if (!result || result == -EEXIST)
iint->flags |= IMA_MEASURED;
if (result < 0)
kfree(entry);
ima_free_template_entry(entry);
}
void ima_audit_measurement(struct integrity_iint_cache *iint,

2
security/integrity/ima/ima_init.c

@ -75,7 +75,7 @@ static void __init ima_add_boot_aggregate(void)
result = ima_store_template(entry, violation, NULL,
boot_aggregate_name);
if (result < 0)
kfree(entry);
ima_free_template_entry(entry);
return;
err_out:
integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,

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