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| author | Jason A. Donenfeld <Jason@zx2c4.com> | 2022-09-22 17:28:47 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-10-01 21:16:36 +0200 |
| commit | cc63374a5a7c240b7d3be734ef589dabbefc7527 (patch) | |
| tree | c699a9e982ce11aa29dcf6082a536e30e2b456d3 /hw/i386 | |
| parent | c4ef867f2949bf2a2ae18a4e27cf1a34bbc8aecb (diff) | |
| download | qemu-cc63374a5a7c240b7d3be734ef589dabbefc7527.zip qemu-cc63374a5a7c240b7d3be734ef589dabbefc7527.tar.gz qemu-cc63374a5a7c240b7d3be734ef589dabbefc7527.tar.bz2 | |
x86: re-initialize RNG seed when selecting kernel
We don't want it to be possible to re-read the RNG seed after ingesting
it, because this ruins forward secrecy. Currently, however, the setup
data section can just be re-read. Since the kernel is always read after
the setup data, use the selection of the kernel as a trigger to
re-initialize the RNG seed, just like we do on reboot, to preserve
forward secrecy.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Message-Id: <20220922152847.3670513-1-Jason@zx2c4.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw/i386')
| -rw-r--r-- | hw/i386/x86.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/hw/i386/x86.c b/hw/i386/x86.c index f9a4dda..1148f70 100644 --- a/hw/i386/x86.c +++ b/hw/i386/x86.c @@ -1112,11 +1112,14 @@ void x86_load_linux(X86MachineState *x86ms, 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_bytes_callback(fw_cfg, FW_CFG_KERNEL_DATA, reset_rng_seed, NULL, + setup_data, kernel, kernel_size, true); + } else { + fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size); } fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr); fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, kernel_size); - fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size); sev_load_ctx.kernel_data = (char *)kernel; sev_load_ctx.kernel_size = kernel_size; |