diff options
Diffstat (limited to 'meta/recipes-kernel/kexec/kexec-tools/0001-arm64-kexec-disabled-check-if-kaslr-seed-dtb-propert.patch')
| -rw-r--r-- | meta/recipes-kernel/kexec/kexec-tools/0001-arm64-kexec-disabled-check-if-kaslr-seed-dtb-propert.patch | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/meta/recipes-kernel/kexec/kexec-tools/0001-arm64-kexec-disabled-check-if-kaslr-seed-dtb-propert.patch b/meta/recipes-kernel/kexec/kexec-tools/0001-arm64-kexec-disabled-check-if-kaslr-seed-dtb-propert.patch new file mode 100644 index 0000000000..ddc1519126 --- /dev/null +++ b/meta/recipes-kernel/kexec/kexec-tools/0001-arm64-kexec-disabled-check-if-kaslr-seed-dtb-propert.patch @@ -0,0 +1,70 @@ +From d48ec5e1a5fb7907520dee71b1d94045486a0c29 Mon Sep 17 00:00:00 2001 +From: Alexander Kamensky <alexander.kamensky42@gmail.com> +Date: Thu, 12 Nov 2020 12:56:46 -0800 +Subject: [PATCH] arm64: kexec: disabled check if kaslr-seed dtb property was + wiped + +Kexec when loading arm64 kernel checks if chosen/kaslr-seed dtb property is +wiped. It's a good assertion to verify proper behavior of kernel. However, +if bootloader creates and fills kaslr-seed property and kernel is not +configured with CONFIG_RANDOMIZE_BASE then logic of reading and wiping +kaslr-seed does not run. As a result kaslr-seed property is not zero and when +kexec tries to load secondary kernel it fails with the following message: + +setup_2nd_dtb: kaslr-seed is not wiped to 0. +kexec: setup_2nd_dtb failed. +kexec: load failed. + +This was observed on Yocto Project on qemuarm64 machine with 5.8 kernel, +qemu 5.1.0. Qemu created kaslr-seed property but kernel was not configured +with CONFIG_RANDOMIZE_BASE. + +Although check has some value, there is a use-case where it breaks kexec, +this patch removes it. + +Note in described use-case the fact that kaslr-seed is not wiped and user +readable through /sys/firmware/fdt or +/sys/firmware/devicetree/base/chosen/kaslr-seed is not a security problem +as kaslr is disabled anyway. + +Signed-off-by: Alexander Kamensky <alexander.kamensky42@gmail.com> +Upstream-Status: Submitted [http://lists.infradead.org/pipermail/kexec/2020-November/021740.html] +--- + kexec/arch/arm64/kexec-arm64.c | 14 +------------- + 1 file changed, 1 insertion(+), 13 deletions(-) + +diff --git a/kexec/arch/arm64/kexec-arm64.c b/kexec/arch/arm64/kexec-arm64.c +index ec6df4b..10238d9 100644 +--- a/kexec/arch/arm64/kexec-arm64.c ++++ b/kexec/arch/arm64/kexec-arm64.c +@@ -503,7 +503,7 @@ static int setup_2nd_dtb(struct dtb *dtb, char *command_line, int on_crash) + int len, range_len; + int nodeoffset; + int new_size; +- int i, result, kaslr_seed; ++ int i, result; + + result = fdt_check_header(dtb->buf); + +@@ -576,18 +576,6 @@ static int setup_2nd_dtb(struct dtb *dtb, char *command_line, int on_crash) + return result; + } + } else { +- kaslr_seed = fdt64_to_cpu(*prop); +- +- /* kaslr_seed must be wiped clean by primary +- * kernel during boot +- */ +- if (kaslr_seed != 0) { +- dbgprintf("%s: kaslr-seed is not wiped to 0.\n", +- __func__); +- result = -EINVAL; +- goto on_error; +- } +- + /* + * Invoke the getrandom system call with + * GRND_NONBLOCK, to make sure we +-- +2.25.1 + |