ima_queued_keys() is called from a non-interrupt context, but
ima_process_queued_keys() may be called from both an interrupt
context (ima_timer_handler) and non-interrupt context
(ima_update_policy). Since the spinlock named ima_keys_lock is used
in both ima_queued_keys() and ima_process_queued_keys(),
irq version of the spinlock macros, spin_lock_irqsave() and
spin_unlock_irqrestore(), should be used[1].
This patch fixes the "inconsistent lock state" issue caused by
using the non-irq version of the spinlock macros in ima_queue_key()
and ima_process_queued_keys().
[1] Documentation/locking/spinlocks.rst
Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
Reported-by: syzbot <syzbot+a4a503d7f37292ae1664@xxxxxxxxxxxxxxxxxxxxxxxxx>
Suggested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Fixes: 8f5d2d06f217 ("IMA: Defined timer to free queued keys")
Fixes: 9fb38e76b5f1 ("IMA: Define workqueue for early boot key measurements")
---
security/integrity/ima/ima_asymmetric_keys.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/security/integrity/ima/ima_asymmetric_keys.c b/security/integrity/ima/ima_asymmetric_keys.c
index 61e478f9e819..381f51708e7b 100644
--- a/security/integrity/ima/ima_asymmetric_keys.c
+++ b/security/integrity/ima/ima_asymmetric_keys.c
@@ -103,17 +103,18 @@ static bool ima_queue_key(struct key *keyring, const void *payload,
{
bool queued = false;
struct ima_key_entry *entry;
+ unsigned long flags;
entry = ima_alloc_key_entry(keyring, payload, payload_len);
if (!entry)
return false;
- spin_lock(&ima_keys_lock);
+ spin_lock_irqsave(&ima_keys_lock, flags);
if (!ima_process_keys) {
list_add_tail(&entry->list, &ima_keys);
queued = true;
}
- spin_unlock(&ima_keys_lock);
+ spin_unlock_irqrestore(&ima_keys_lock, flags);
if (!queued)
ima_free_key_entry(entry);
@@ -131,6 +132,7 @@ void ima_process_queued_keys(void)
{
struct ima_key_entry *entry, *tmp;
bool process = false;
+ unsigned long flags;
if (ima_process_keys)
return;
@@ -141,12 +143,12 @@ void ima_process_queued_keys(void)
* First one setting the ima_process_keys flag to true will
* process the queued keys.
*/
- spin_lock(&ima_keys_lock);
+ spin_lock_irqsave(&ima_keys_lock, flags);
if (!ima_process_keys) {
ima_process_keys = true;
process = true;
}
- spin_unlock(&ima_keys_lock);
+ spin_unlock_irqrestore(&ima_keys_lock, flags);
if (!process)
return;
--
2.17.1
