From: Linus Torvalds torvalds@linux-foundation.org
commit 69cbeb61ff9093a9155cb19a36d633033f71093a upstream.
This reverts commit e7b813b32a42a3a6281a4fd9ae7700a0257c1d50 (and the subsequent fix for it: 41a15855c1ee "efi: random: fix NULL-deref when refreshing seed").
It turns otu to cause non-deterministic boot stalls on at least a HP 6730b laptop.
Reported-and-bisected-by: Sami Korkalainen sami.korkalainen@proton.me Link: https://lore.kernel.org/all/GQUnKz2al3yke5mB2i1kp3SzNHjK8vi6KJEh7rnLrOQ24Orl... Cc: Jason A. Donenfeld Jason@zx2c4.com Cc: Bagas Sanjaya bagasdotme@gmail.com Cc: stable@kernel.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/firmware/efi/efi.c | 21 --------------------- 1 file changed, 21 deletions(-)
--- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -361,24 +361,6 @@ static void __init efi_debugfs_init(void static inline void efi_debugfs_init(void) {} #endif
-static void refresh_nv_rng_seed(struct work_struct *work) -{ - u8 seed[EFI_RANDOM_SEED_SIZE]; - - get_random_bytes(seed, sizeof(seed)); - efi.set_variable(L"RandomSeed", &LINUX_EFI_RANDOM_SEED_TABLE_GUID, - EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | - EFI_VARIABLE_RUNTIME_ACCESS, sizeof(seed), seed); - memzero_explicit(seed, sizeof(seed)); -} -static int refresh_nv_rng_seed_notification(struct notifier_block *nb, unsigned long action, void *data) -{ - static DECLARE_WORK(work, refresh_nv_rng_seed); - schedule_work(&work); - return NOTIFY_DONE; -} -static struct notifier_block refresh_nv_rng_seed_nb = { .notifier_call = refresh_nv_rng_seed_notification }; - /* * We register the efi subsystem with the firmware subsystem and the * efivars subsystem with the efi subsystem, if the system was booted with @@ -451,9 +433,6 @@ static int __init efisubsys_init(void) platform_device_register_simple("efi_secret", 0, NULL, 0); #endif
- if (efi_rt_services_supported(EFI_RT_SUPPORTED_SET_VARIABLE)) - execute_with_initialized_rng(&refresh_nv_rng_seed_nb); - return 0;
err_remove_group: