Re: [PATCH] block: keyslot-manager: fix error return code of blk_ksm_evict_key()

[Jia-Ju Bai]

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 <os...@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com>
---
  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