Messages in this thread Patch in this message | | | From | Hans-Christian Noren Egtvedt <> | Subject | [v4.9 PATCH 6/6] random: move rand_initialize() earlier | Date | Sun, 31 Jul 2022 20:26:36 +0200 |
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From: Kees Cook <keescook@chromium.org>
Right now rand_initialize() is run as an early_initcall(), but it only depends on timekeeping_init() (for mixing ktime_get_real() into the pools). However, the call to boot_init_stack_canary() for stack canary initialization runs earlier, which triggers a warning at boot:
random: get_random_bytes called from start_kernel+0x357/0x548 with crng_init=0
Instead, this moves rand_initialize() to after timekeeping_init(), and moves canary initialization here as well.
Note that this warning may still remain for machines that do not have UEFI RNG support (which initializes the RNG pools during setup_arch()), or for x86 machines without RDRAND (or booting without "random.trust=on" or CONFIG_RANDOM_TRUST_CPU=y).
Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu> (cherry picked from commit d55535232c3dbde9a523a9d10d68670f5fe5dec3)
Adjusted to fit on top of linux-4.9.y branch, suspecting a wrongly solved conflict when cherry picked earlier. --- init/main.c | 7 ------- 1 file changed, 7 deletions(-)
diff --git a/init/main.c b/init/main.c index 6bc1a3fa152..6537f51a0ba 100644 --- a/init/main.c +++ b/init/main.c @@ -500,13 +500,6 @@ asmlinkage __visible void __init start_kernel(void) page_address_init(); pr_notice("%s", linux_banner); setup_arch(&command_line); - /* - * Set up the the initial canary and entropy after arch - * and after adding latent and command line entropy. - */ - add_latent_entropy(); - add_device_randomness(command_line, strlen(command_line)); - boot_init_stack_canary(); mm_init_cpumask(&init_mm); setup_command_line(command_line); setup_nr_cpu_ids(); -- 2.34.1
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