[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v5 3/4] x86: reinitialize RNG seed on system reboot
From: |
Jason A. Donenfeld |
Subject: |
[PATCH v5 3/4] x86: reinitialize RNG seed on system reboot |
Date: |
Wed, 21 Sep 2022 11:31:33 +0200 |
Since this is read from fw_cfg on each boot, the kernel zeroing it out
alone is insufficient to prevent it from being used twice. And indeed on
reboot we always want a new seed, not the old one. So re-fill it in this
circumstance.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
hw/i386/x86.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 1ee0b1b413..f9a4ddaa4a 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -783,6 +783,12 @@ static void reset_setup_data(void *opaque)
stq_p(fixup->pos, fixup->orig_val);
}
+static void reset_rng_seed(void *opaque)
+{
+ SetupData *setup_data = opaque;
+ qemu_guest_getrandom_nofail(setup_data->data,
le32_to_cpu(setup_data->len));
+}
+
void x86_load_linux(X86MachineState *x86ms,
FWCfgState *fw_cfg,
int acpi_data_size,
@@ -1105,6 +1111,7 @@ void x86_load_linux(X86MachineState *x86ms,
setup_data->type = cpu_to_le32(SETUP_RNG_SEED);
setup_data->len = cpu_to_le32(RNG_SEED_LENGTH);
qemu_guest_getrandom_nofail(setup_data->data, RNG_SEED_LENGTH);
+ qemu_register_reset(reset_rng_seed, setup_data);
}
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr);
--
2.37.3