linux/arch/riscv
Liao Chang b7fb4d78a6
RISC-V: use memcpy for kexec_file mode
The pointer to buffer loading kernel binaries is in kernel space for
kexec_fil mode, When copy_from_user copies data from pointer to a block
of memory, it checkes that the pointer is in the user space range, on
RISCV-V that is:

static inline bool __access_ok(unsigned long addr, unsigned long size)
{
	return size <= TASK_SIZE && addr <= TASK_SIZE - size;
}

and TASK_SIZE is 0x4000000000 for 64-bits, which now causes
copy_from_user to reject the access of the field 'buf' of struct
kexec_segment that is in range [CONFIG_PAGE_OFFSET - VMALLOC_SIZE,
CONFIG_PAGE_OFFSET), is invalid user space pointer.

This patch fixes this issue by skipping access_ok(), use mempcy() instead.

Signed-off-by: Liao Chang <liaochang1@huawei.com>
Link: https://lore.kernel.org/r/20220408100914.150110-3-lizhengyu3@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-05-19 11:53:41 -07:00
..
boot RISC-V Patches for the 5.18 Merge Window, Part 2 2022-04-01 13:31:57 -07:00
configs RISC-V: K210 defconfigs: Drop redundant MEMBARRIER=n 2022-03-31 17:19:27 -07:00
errata riscv: errata: alternative: mark vendor_patch_func __initdata 2022-01-09 11:02:46 -08:00
include RISC-V Patches for the 5.18 Merge Window, Part 2 2022-04-01 13:31:57 -07:00
kernel RISC-V: use memcpy for kexec_file mode 2022-05-19 11:53:41 -07:00
kvm RISC-V: KVM: Implement SBI HSM suspend call 2022-03-11 19:02:39 +05:30
lib riscv: Fixed misaligned memory access. Fixed pointer comparison. 2022-03-10 10:24:04 -08:00
mm RISC-V Patches for the 5.18 Merge Window, Part 1 2022-03-25 10:11:38 -07:00
net riscv: bpf: Fix eBPF's exception tables 2022-01-19 10:50:02 -08:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig RISC-V CPU Idle Support 2022-03-30 16:17:54 -07:00
Kconfig.debug RISC-V: Remove EARLY_PRINTK support 2018-12-17 10:23:46 -08:00
Kconfig.erratas riscv: alternative only works on !XIP_KERNEL 2022-03-10 10:05:19 -08:00
Kconfig.socs RISC-V CPU Idle Support 2022-03-30 16:17:54 -07:00
Makefile riscv: fix build with binutils 2.38 2022-02-10 09:17:01 -08:00