[PATCH] crypto: jitter - fix intermediary handling
From: Markus Theil
Date: Sat Jun 21 2025 - 07:37:03 EST
The intermediary value was included in the wrong
hash state. While there, adapt to user-space by
setting the timestamp to 0 if stuck and inserting
the values nevertheless.
Acked-by: Stephan Mueller <smueller@xxxxxxxxxx>
Signed-off-by: Markus Theil <theil.markus@xxxxxxxxx>
---
crypto/jitterentropy-kcapi.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/crypto/jitterentropy-kcapi.c b/crypto/jitterentropy-kcapi.c
index c24d4ff2b4a8..1266eb790708 100644
--- a/crypto/jitterentropy-kcapi.c
+++ b/crypto/jitterentropy-kcapi.c
@@ -144,7 +144,7 @@ int jent_hash_time(void *hash_state, __u64 time, u8 *addtl,
* Inject the data from the previous loop into the pool. This data is
* not considered to contain any entropy, but it stirs the pool a bit.
*/
- ret = crypto_shash_update(desc, intermediary, sizeof(intermediary));
+ ret = crypto_shash_update(hash_state_desc, intermediary, sizeof(intermediary));
if (ret)
goto err;
@@ -157,11 +157,12 @@ int jent_hash_time(void *hash_state, __u64 time, u8 *addtl,
* conditioning operation to have an identical amount of input data
* according to section 3.1.5.
*/
- if (!stuck) {
- ret = crypto_shash_update(hash_state_desc, (u8 *)&time,
- sizeof(__u64));
+ if (stuck) {
+ time = 0;
}
+ ret = crypto_shash_update(hash_state_desc, (u8 *)&time, sizeof(__u64));
+
err:
shash_desc_zero(desc);
memzero_explicit(intermediary, sizeof(intermediary));
--
2.49.0