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Subject[PATCH v2 2/2] kfence: use better stack hash seed
Date
As of the prior commit, the RNG will have incorporated both a cycle
counter value and RDRAND, in addition to various other environmental
noise. Therefore, using get_random_u32() will supply a stronger seed
than simply using random_get_entropy(). N.B.: random_get_entropy()
should be considered an internal API of random.c and not generally
consumed.

Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
mm/kfence/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index c252081b11df..239b1b4b094f 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -864,7 +864,7 @@ static void kfence_init_enable(void)

void __init kfence_init(void)
{
- stack_hash_seed = (u32)random_get_entropy();
+ stack_hash_seed = get_random_u32();

/* Setting kfence_sample_interval to 0 on boot disables KFENCE. */
if (!kfence_sample_interval)
--
2.37.3
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