efi/libstub: arm64: Warn when efi_random_alloc() fails
authorArd Biesheuvel <ardb@kernel.org>
Mon, 26 Jul 2021 14:24:01 +0000 (16:24 +0200)
committerArd Biesheuvel <ardb@kernel.org>
Tue, 3 Aug 2021 05:43:07 +0000 (07:43 +0200)
commitff80ef5bf5bd59e5eab82d1d846acc613ebbf6c4
tree5112b8bff7532ef4f26bdcb4404117387d2c8c47
parent3a262423755b83a5f85009ace415d6e7f572dfe8
efi/libstub: arm64: Warn when efi_random_alloc() fails

Randomization of the physical load address of the kernel image relies on
efi_random_alloc() returning successfully, and currently, we ignore any
failures and just carry on, using the ordinary, non-randomized page
allocator routine. This means we never find out if a failure occurs,
which could harm security, so let's at least warn about this condition.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
drivers/firmware/efi/libstub/arm64-stub.c