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| author |   Ard Biesheuvel <ardb@kernel.org> | 2022-10-20 10:39:08 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2022-10-24 10:21:02 +0200 |
| commit | 161a438d730dade2ba2b1bf8785f0759aba4ca5f (patch) | |
| tree | 08ae9c2b254af749636e5653e9223e04324ea83b /include | |
| parent | efi/tpm: Pass correct address to memblock_reserve (diff) | |
| download | linux-dev-161a438d730dade2ba2b1bf8785f0759aba4ca5f.tar.xz linux-dev-161a438d730dade2ba2b1bf8785f0759aba4ca5f.zip | |
efi: random: reduce seed size to 32 bytes
We no longer need at least 64 bytes of random seed to permit the early
crng init to complete. The RNG is now based on Blake2s, so reduce the
EFI seed size to the Blake2s hash size, which is sufficient for our
purposes.
While at it, drop the READ_ONCE(), which was supposed to prevent size
from being evaluated after seed was unmapped. However, this cannot
actually happen, so READ_ONCE() is unnecessary here.
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/efi.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/efi.h b/include/linux/efi.h index 80f3c1c7827d..929d559ad41d 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1222,7 +1222,7 @@ efi_status_t efi_random_get_seed(void); arch_efi_call_virt_teardown(); \ }) -#define EFI_RANDOM_SEED_SIZE 64U +#define EFI_RANDOM_SEED_SIZE 32U // BLAKE2S_HASH_SIZE struct linux_efi_random_seed { u32 size; |