diff options
author | Lakshmi Ramasubramanian <nramas@linux.microsoft.com> | 2020-01-22 17:32:06 -0800 |
---|---|---|
committer | Mimi Zohar <zohar@linux.ibm.com> | 2020-01-23 07:37:31 -0500 |
commit | 5b3014b95272a432b7705142f7081967fc1547f9 (patch) | |
tree | 3290001b6ae913d289b6eedb60f59acce50d64bf | |
parent | 450d0fd515648dcd90a9940b498f9913ed69566b (diff) | |
download | linux-5b3014b95272a432b7705142f7081967fc1547f9.tar.gz linux-5b3014b95272a432b7705142f7081967fc1547f9.tar.bz2 linux-5b3014b95272a432b7705142f7081967fc1547f9.zip |
IMA: Defined delayed workqueue to free the queued keys
Keys queued for measurement should be freed if a custom IMA policy
was not loaded. Otherwise, the keys will remain queued forever
consuming kernel memory.
This patch defines a delayed workqueue to handle the above scenario.
The workqueue handler is setup to execute 5 minutes after IMA
initialization is completed.
If a custom IMA policy is loaded before the workqueue handler is
scheduled to execute, the workqueue task is cancelled and any queued keys
are processed for measurement. But if a custom policy was not loaded then
the queued keys are just freed when the delayed workqueue handler is run.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reported-by: kernel test robot <rong.a.chen@intel.com> # sleeping
function called from invalid context
Reported-by: kbuild test robot <lkp@intel.com> # redefinition of
ima_init_key_queue() function.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
-rw-r--r-- | security/integrity/ima/ima.h | 2 | ||||
-rw-r--r-- | security/integrity/ima/ima_init.c | 8 | ||||
-rw-r--r-- | security/integrity/ima/ima_queue_keys.c | 44 |
3 files changed, 48 insertions, 6 deletions
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 905ed2f7f778..64317d95363e 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -215,11 +215,13 @@ struct ima_key_entry { size_t payload_len; char *keyring_name; }; +void ima_init_key_queue(void); bool ima_should_queue_key(void); bool ima_queue_key(struct key *keyring, const void *payload, size_t payload_len); void ima_process_queued_keys(void); #else +static inline void ima_init_key_queue(void) {} static inline bool ima_should_queue_key(void) { return false; } static inline bool ima_queue_key(struct key *keyring, const void *payload, diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 5d55ade5f3b9..195cb4079b2b 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -131,5 +131,11 @@ int __init ima_init(void) ima_init_policy(); - return ima_fs_init(); + rc = ima_fs_init(); + if (rc != 0) + return rc; + + ima_init_key_queue(); + + return rc; } diff --git a/security/integrity/ima/ima_queue_keys.c b/security/integrity/ima/ima_queue_keys.c index 9b561f2b86db..c87c72299191 100644 --- a/security/integrity/ima/ima_queue_keys.c +++ b/security/integrity/ima/ima_queue_keys.c @@ -10,6 +10,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/workqueue.h> #include <keys/asymmetric-type.h> #include "ima.h" @@ -25,6 +26,36 @@ static bool ima_process_keys; static DEFINE_MUTEX(ima_keys_lock); static LIST_HEAD(ima_keys); +/* + * If custom IMA policy is not loaded then keys queued up + * for measurement should be freed. This worker is used + * for handling this scenario. + */ +static long ima_key_queue_timeout = 300000; /* 5 Minutes */ +static void ima_keys_handler(struct work_struct *work); +static DECLARE_DELAYED_WORK(ima_keys_delayed_work, ima_keys_handler); +static bool timer_expired; + +/* + * This worker function frees keys that may still be + * queued up in case custom IMA policy was not loaded. + */ +static void ima_keys_handler(struct work_struct *work) +{ + timer_expired = true; + ima_process_queued_keys(); +} + +/* + * This function sets up a worker to free queued keys in case + * custom IMA policy was never loaded. + */ +void ima_init_key_queue(void) +{ + schedule_delayed_work(&ima_keys_delayed_work, + msecs_to_jiffies(ima_key_queue_timeout)); +} + static void ima_free_key_entry(struct ima_key_entry *entry) { if (entry) { @@ -119,13 +150,16 @@ void ima_process_queued_keys(void) if (!process) return; + if (!timer_expired) + cancel_delayed_work_sync(&ima_keys_delayed_work); list_for_each_entry_safe(entry, tmp, &ima_keys, list) { - process_buffer_measurement(entry->payload, - entry->payload_len, - entry->keyring_name, - KEY_CHECK, 0, - entry->keyring_name); + if (!timer_expired) + process_buffer_measurement(entry->payload, + entry->payload_len, + entry->keyring_name, + KEY_CHECK, 0, + entry->keyring_name); list_del(&entry->list); ima_free_key_entry(entry); } |