From: Yuntao Wang <ytcoode@xxxxxxxxx>
[ Commit 01638431c465741e071ab34acf3bef3c2570f878 upstream ]
When KASLR is enabled, the KASLR_FLAG bit in boot_params->hdr.loadflags
should be set to 1 to propagate KASLR status from compressed kernel to
kernel, just as the choose_random_location() function does.
Currently, when the kernel is booted via the EFI stub, the KASLR_FLAG
bit in boot_params->hdr.loadflags is not set, even though it should be.
This causes some functions, such as kernel_randomize_memory(), not to
execute as expected. Fix it.
Fixes: a1b87d54f4e4 ("x86/efistub: Avoid legacy decompressor when doing EFI boot")
Signed-off-by: Yuntao Wang <ytcoode@xxxxxxxxx>
[ardb: drop 'else' branch clearing KASLR_FLAG]
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
drivers/firmware/efi/libstub/x86-stub.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index b183b40195ee..a0757a37b482 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -781,6 +781,8 @@ static efi_status_t efi_decompress_kernel(unsigned long *kernel_entry)
efi_debug("AMI firmware v2.0 or older detected - disabling physical KASLR\n");
seed[0] = 0;
}
+
+ boot_params_ptr->hdr.loadflags |= KASLR_FLAG;
}
status = efi_random_alloc(alloc_size, CONFIG_PHYSICAL_ALIGN, &addr,
--
2.44.0.278.ge034bb2e1d-goog
