crypto: jitter - Mark intermediary memory as clean

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@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e8bcd7ee3db6cb5cb875
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/jitterentropy-kcapi.c b/crypto/jitterentropy-kcapi.c
index 1266eb790708b878cdc0c9b7ffb3d7c29a05500c..a53de7affe8d1babfe4b50ba4b572e87f3354b26 100644 (file)
--- 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.