From 2666c3e62b8159e8aa079ef34bfde3aba6e128e5 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 19 Oct 2021 18:01:37 +0800 Subject: [PATCH] efi/libstub: arm64: Double check image alignment at entry stable inclusion from stable-5.10.60 commit 4a948c579ed6a12e248da57b9422a69b1ca2261c bugzilla: 177018 https://gitee.com/openeuler/kernel/issues/I4EAUG Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4a948c579ed6a12e248da57b9422a69b1ca2261c -------------------------------- commit c32ac11da3f83bb42b986702a9b92f0a14ed4182 upstream. On arm64, the stub only moves the kernel image around in memory if needed, which is typically only for KASLR, given that relocatable kernels (which is the default) can run from any 64k aligned address, which is also the minimum alignment communicated to EFI via the PE/COFF header. Unfortunately, some loaders appear to ignore this header, and load the kernel at some arbitrary offset in memory. We can deal with this, but let's check for this condition anyway, so non-compliant code can be spotted and fixed. Cc: # v5.10+ Signed-off-by: Ard Biesheuvel Tested-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman Signed-off-by: Chen Jun Acked-by: Weilong Chen Signed-off-by: Chen Jun Signed-off-by: Zheng Zengkai --- drivers/firmware/efi/libstub/arm64-stub.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c index 881e157fdedc..c1b57dfb1277 100644 --- a/drivers/firmware/efi/libstub/arm64-stub.c +++ b/drivers/firmware/efi/libstub/arm64-stub.c @@ -119,6 +119,10 @@ efi_status_t handle_kernel_image(unsigned long *image_addr, if (image->image_base != _text) efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n"); + if (!IS_ALIGNED((u64)_text, EFI_KIMG_ALIGN)) + efi_err("FIRMWARE BUG: kernel image not aligned on %ldk boundary\n", + EFI_KIMG_ALIGN >> 10); + kernel_size = _edata - _text; kernel_memsize = kernel_size + (_end - _edata); *reserve_size = kernel_memsize; -- GitLab