From 2f7c68cb55ecb7331f2381deb497c27155f32faf Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 03 Jan 2024 09:43:39 +0000
Subject: [PATCH] update kernel to 5.10.198
---
kernel/drivers/firmware/efi/libstub/random.c | 42 ++++++++++++++++++++++++++++++++++++------
1 files changed, 36 insertions(+), 6 deletions(-)
diff --git a/kernel/drivers/firmware/efi/libstub/random.c b/kernel/drivers/firmware/efi/libstub/random.c
index 33ab567..f85d2c0 100644
--- a/kernel/drivers/firmware/efi/libstub/random.c
+++ b/kernel/drivers/firmware/efi/libstub/random.c
@@ -67,8 +67,9 @@
efi_guid_t rng_proto = EFI_RNG_PROTOCOL_GUID;
efi_guid_t rng_algo_raw = EFI_RNG_ALGORITHM_RAW;
efi_guid_t rng_table_guid = LINUX_EFI_RANDOM_SEED_TABLE_GUID;
+ struct linux_efi_random_seed *prev_seed, *seed = NULL;
+ int prev_seed_size = 0, seed_size = EFI_RANDOM_SEED_SIZE;
efi_rng_protocol_t *rng = NULL;
- struct linux_efi_random_seed *seed = NULL;
efi_status_t status;
status = efi_bs_call(locate_protocol, &rng_proto, NULL, (void **)&rng);
@@ -76,18 +77,33 @@
return status;
/*
+ * Check whether a seed was provided by a prior boot stage. In that
+ * case, instead of overwriting it, let's create a new buffer that can
+ * hold both, and concatenate the existing and the new seeds.
+ * Note that we should read the seed size with caution, in case the
+ * table got corrupted in memory somehow.
+ */
+ prev_seed = get_efi_config_table(LINUX_EFI_RANDOM_SEED_TABLE_GUID);
+ if (prev_seed && prev_seed->size <= 512U) {
+ prev_seed_size = prev_seed->size;
+ seed_size += prev_seed_size;
+ }
+
+ /*
* Use EFI_ACPI_RECLAIM_MEMORY here so that it is guaranteed that the
* allocation will survive a kexec reboot (although we refresh the seed
* beforehand)
*/
status = efi_bs_call(allocate_pool, EFI_ACPI_RECLAIM_MEMORY,
- sizeof(*seed) + EFI_RANDOM_SEED_SIZE,
+ struct_size(seed, bits, seed_size),
(void **)&seed);
- if (status != EFI_SUCCESS)
- return status;
+ if (status != EFI_SUCCESS) {
+ efi_warn("Failed to allocate memory for RNG seed.\n");
+ goto err_warn;
+ }
status = efi_call_proto(rng, get_rng, &rng_algo_raw,
- EFI_RANDOM_SEED_SIZE, seed->bits);
+ EFI_RANDOM_SEED_SIZE, seed->bits);
if (status == EFI_UNSUPPORTED)
/*
@@ -100,14 +116,28 @@
if (status != EFI_SUCCESS)
goto err_freepool;
- seed->size = EFI_RANDOM_SEED_SIZE;
+ seed->size = seed_size;
+ if (prev_seed_size)
+ memcpy(seed->bits + EFI_RANDOM_SEED_SIZE, prev_seed->bits,
+ prev_seed_size);
+
status = efi_bs_call(install_configuration_table, &rng_table_guid, seed);
if (status != EFI_SUCCESS)
goto err_freepool;
+ if (prev_seed_size) {
+ /* wipe and free the old seed if we managed to install the new one */
+ memzero_explicit(prev_seed->bits, prev_seed_size);
+ efi_bs_call(free_pool, prev_seed);
+ }
return EFI_SUCCESS;
err_freepool:
+ memzero_explicit(seed, struct_size(seed, bits, seed_size));
efi_bs_call(free_pool, seed);
+ efi_warn("Failed to obtain seed from EFI_RNG_PROTOCOL\n");
+err_warn:
+ if (prev_seed)
+ efi_warn("Retaining bootloader-supplied seed only");
return status;
}
--
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