When blk_ksm_find_keyslot() returns NULL to slot, no error return code
of blk_ksm_evict_key() is assigned.
To fix this bug, err is assigned with -ENOENT in this case.
Fixes: 1b2628397058 ("block: Keyslot Manager for Inline Encryption")
Reported-by: TOTE Robot <[email protected]>
Signed-off-by: Jia-Ju Bai <[email protected]>
---
block/keyslot-manager.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c
index 2c4a55bea6ca..4dd5da0645bc 100644
--- a/block/keyslot-manager.c
+++ b/block/keyslot-manager.c
@@ -375,8 +375,10 @@ int blk_ksm_evict_key(struct blk_keyslot_manager *ksm,
blk_ksm_hw_enter(ksm);
slot = blk_ksm_find_keyslot(ksm, key);
- if (!slot)
+ if (!slot) {
+ err = -ENOENT;
goto out_unlock;
+ }
if (WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)) {
err = -EBUSY;
--
2.17.1
On Tue, Mar 09, 2021 at 01:18:12AM -0800, Jia-Ju Bai wrote:
> When blk_ksm_find_keyslot() returns NULL to slot, no error return code
> of blk_ksm_evict_key() is assigned.
> To fix this bug, err is assigned with -ENOENT in this case.
>
> Fixes: 1b2628397058 ("block: Keyslot Manager for Inline Encryption")
> Reported-by: TOTE Robot <[email protected]>
> Signed-off-by: Jia-Ju Bai <[email protected]>
> ---
> block/keyslot-manager.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c
> index 2c4a55bea6ca..4dd5da0645bc 100644
> --- a/block/keyslot-manager.c
> +++ b/block/keyslot-manager.c
> @@ -375,8 +375,10 @@ int blk_ksm_evict_key(struct blk_keyslot_manager *ksm,
>
> blk_ksm_hw_enter(ksm);
> slot = blk_ksm_find_keyslot(ksm, key);
> - if (!slot)
> + if (!slot) {
> + err = -ENOENT;
> goto out_unlock;
> + }
>
> if (WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)) {
> err = -EBUSY;
> --
> 2.17.1
>
This function was deliberately designed to return 0 on success *and also*
if there's no keyslot found with the specified key - i.e. it returns 0 if
the key is no longer programmed into the keyslot manager, which is what the
callers care about, so I don't think there's a bug here.
Also if we were to apply this patch, we'd also need to change the callers
to handle this new -ENOENT case (and not treat it as an error/not propogate
-ENOENT in e.g. dm_keyslot_evict_callback()).
Is there a reason we want to change the behaviour of this function?
On 2021/3/9 19:45, Satya Tangirala wrote:
> On Tue, Mar 09, 2021 at 01:18:12AM -0800, Jia-Ju Bai wrote:
>> When blk_ksm_find_keyslot() returns NULL to slot, no error return code
>> of blk_ksm_evict_key() is assigned.
>> To fix this bug, err is assigned with -ENOENT in this case.
>>
>> Fixes: 1b2628397058 ("block: Keyslot Manager for Inline Encryption")
>> Reported-by: TOTE Robot <[email protected]>
>> Signed-off-by: Jia-Ju Bai <[email protected]>
>> ---
>> block/keyslot-manager.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c
>> index 2c4a55bea6ca..4dd5da0645bc 100644
>> --- a/block/keyslot-manager.c
>> +++ b/block/keyslot-manager.c
>> @@ -375,8 +375,10 @@ int blk_ksm_evict_key(struct blk_keyslot_manager *ksm,
>>
>> blk_ksm_hw_enter(ksm);
>> slot = blk_ksm_find_keyslot(ksm, key);
>> - if (!slot)
>> + if (!slot) {
>> + err = -ENOENT;
>> goto out_unlock;
>> + }
>>
>> if (WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)) {
>> err = -EBUSY;
>> --
>> 2.17.1
>>
> This function was deliberately designed to return 0 on success *and also*
> if there's no keyslot found with the specified key - i.e. it returns 0 if
> the key is no longer programmed into the keyslot manager, which is what the
> callers care about, so I don't think there's a bug here.
Thanks for the reply and explanation!
It seems like a false positive here, and I am sorry for this false report.
Best wishes,
Jia-Ju Bai