Messages in this thread Patch in this message | | | From | Johan Hovold <> | Subject | [PATCH] efi: random: fix NULL-deref when refreshing seed | Date | Fri, 16 Dec 2022 10:15:14 +0100 |
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Do not try to refresh the RNG seed in case the firmware does not support setting variables.
This is specifically needed to prevent a NULL-pointer dereference on the Lenovo X13s with some firmware revisions.
Fixes: e7b813b32a42 ("efi: random: refresh non-volatile random seed when RNG is initialized") Reported-by: Steev Klimaszewski <steev@kali.org> Reported-by: Bjorn Andersson <andersson@kernel.org> Signed-off-by: Johan Hovold <johan+linaro@kernel.org> --- drivers/firmware/efi/efi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 2e168e5b97de..1a9e2f70c550 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -432,7 +432,9 @@ static int __init efisubsys_init(void) platform_device_register_simple("efi_secret", 0, NULL, 0); #endif - execute_with_initialized_rng(&refresh_nv_rng_seed_nb); + if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) + execute_with_initialized_rng(&refresh_nv_rng_seed_nb); + return 0; err_remove_group: -- 2.37.4
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