kernel/linux.git/security/integrity/ima/ima_fs.c, branch linux-4.7.y

ima: measure and appraise the IMA policy itself

2016-02-21T14:34:22+00:00

Add support for measuring and appraising the IMA policy itself. Changelog v4: - use braces on both if/else branches, even if single line on one of the branches - Dmitry - Use the id mapping - Dmitry Signed-off-by: Mimi Zohar Acked-by: Petko Manolov Acked-by: Dmitry Kasatkin

ima: load policy using path

2016-02-21T14:34:05+00:00

We currently cannot do appraisal or signature vetting of IMA policies since we currently can only load IMA policies by writing the contents of the policy directly in, as follows: cat policy-file > /ima/policy If we provide the kernel the path to the IMA policy so it can load the policy itself it'd be able to later appraise or vet the file signature if it has one. This patch adds support to load the IMA policy with a given path as follows: echo /etc/ima/ima_policy > /sys/kernel/security/ima/policy Changelog v4+: - moved kernel_read_file_from_path() error messages to callers v3: - moved kernel_read_file_from_path() to a separate patch v2: - after re-ordering the patches, replace calling integrity_kernel_read() to read the file with kernel_read_file_from_path() (Mimi) - Patch description re-written by Luis R. Rodriguez Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar

ima: ima_write_policy() limit locking

2016-01-03T18:22:38+00:00

There is no need to hold the ima_write_mutex for so long. We only need it around ima_parse_add_rule(). Changelog: - The return path now takes into account failed kmalloc() call. Reported-by: Al Viro Signed-off-by: Petko Manolov Signed-off-by: Mimi Zohar

IMA: policy can be updated zero times

2015-12-24T23:56:45+00:00

Commit "IMA: policy can now be updated multiple times" assumed that the policy would be updated at least once. If there are zero updates, the temporary list head object will get added to the policy list, and later dereferenced as an IMA policy object, which means that invalid memory will be accessed. Changelog: - Move list_empty() test to ima_release_policy(), before audit msg - Mimi Signed-off-by: Sasha Levin Signed-off-by: Mimi Zohar

IMA: allow reading back the current IMA policy

2015-12-15T15:01:43+00:00

It is often useful to be able to read back the IMA policy. It is even more important after introducing CONFIG_IMA_WRITE_POLICY. This option allows the root user to see the current policy rules. Signed-off-by: Zbigniew Jasinski Signed-off-by: Petko Manolov Signed-off-by: Mimi Zohar

IMA: policy can now be updated multiple times

2015-12-15T15:01:43+00:00

The new rules get appended to the original policy, forming a queue. The new rules are first added to a temporary list, which on error get released without disturbing the normal IMA operations. On success both lists (the current policy and the new rules) are spliced. IMA policy reads are many orders of magnitude more numerous compared to writes, the match code is RCU protected. The updater side also does list splice in RCU manner. Signed-off-by: Petko Manolov Signed-off-by: Mimi Zohar

ima: fix ima_show_template_data_ascii()

2015-06-16T12:18:21+00:00

This patch fixes a bug introduced in "4d7aeee ima: define new template ima-ng and template fields d-ng and n-ng". Changelog: - change int to uint32 (Roberto Sassu's suggestion) Signed-off-by: Mimi Zohar Signed-off-by: Roberto Sassu Cc: stable@vger.kernel.org # 3.13

ima: display template format in meas. list if template name length is zero

2014-10-13T12:39:01+00:00

With the introduction of the 'ima_template_fmt' kernel cmdline parameter, a user can define a new template descriptor with custom format. However, in this case, userspace tools will be unable to parse the measurements list because the new template is unknown. For this reason, this patch modifies the current IMA behavior to display in the list the template format instead of the name (only if the length of the latter is zero) so that a tool can extract needed information if it can handle listed fields. This patch also correctly displays the error log message in ima_init_template() if the selected template cannot be initialized. Changelog: - v3: - check the first byte of 'e->template_desc->name' instead of using strlen() in ima_fs.c (suggested by Mimi Zohar) - v2: - print the template format in ima_init_template(), if the selected template is custom (Roberto Sassu) - v1: - fixed patch description (Roberto Sassu, suggested by Mimi Zohar) - set 'template_name' variable in ima_fs.c only once (Roberto Sassu, suggested by Mimi Zohar) Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar

ima: use atomic bit operations to protect policy update interface

2014-10-12T03:33:02+00:00

The current implementation uses an atomic counter to provide exclusive access to the sysfs 'policy' entry to update the IMA policy. While it is highly unlikely, the usage of a counter might potentially allow another process to overflow the counter, open the interface and insert additional rules into the policy being loaded. This patch replaces using an atomic counter with atomic bit operations which is more reliable and a widely used method to provide exclusive access. As bit operation keep the interface locked after successful update, it makes it unnecessary to verify if the default policy was set or not during parsing and interface closing. This patch also removes that code. Changes in v3: * move audit log message to ima_relead_policy() to report successful and unsuccessful result * unnecessary comment removed Changes in v2: * keep interface locked after successful policy load as in original design * remove sysfs entry as in original design Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar

ima: report policy load status

2014-10-12T03:25:25+00:00

Audit messages are rate limited, often causing the policy update info to not be visible. Report policy loading status also using pr_info. Changes in v2: * reporting moved to ima_release_policy to notice parsing errors * reporting both completed and failed status Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar