[PATCH V3] crypto: Mark intermediary memory as clean

[Edward Adam Davis]

This is not a leak! The stack memroy is hashed and fed into the
entropy pool. We can't recover the original kernel memory from it.

Reported-by: syzbot+e8bcd7ee3db6cb5cb875@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=e8bcd7ee3db6cb5cb875
Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
---
V1 -> V2: mark it as unpoison
V2 -> V3: replace to sizeof, minimize the possibilities where inconsistencies can occur

 crypto/jitterentropy-kcapi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/crypto/jitterentropy-kcapi.c b/crypto/jitterentropy-kcapi.c
index 1266eb790708..4020a6e41b0e 100644
--- a/crypto/jitterentropy-kcapi.c
+++ b/crypto/jitterentropy-kcapi.c
@@ -117,6 +117,7 @@ int jent_hash_time(void *hash_state, __u64 time, u8 *addtl,
 		pr_warn_ratelimited("Unexpected digest size\n");
 		return -EINVAL;
 	}
+	kmsan_unpoison_memory(intermediary, sizeof(intermediary));
 
 	/*
 	 * This loop fills a buffer which is injected into the entropy pool.
-- 
2.43.0