diff options
| author | Liao Chang <liaochang1@huawei.com> | 2022-04-08 18:09:10 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-05-19 11:53:41 -0700 |
| commit | b7fb4d78a6ade6026d9e5cf438c2a46ab962e032 (patch) | |
| tree | 7511f5ce3a8ffff190131edb850c0f64b475efee /arch/riscv/kernel/machine_kexec.c | |
| parent | 4853f68d158ac59b05985a6af5b7da7ccdbc14c8 (diff) | |
| download | linux-b7fb4d78a6ade6026d9e5cf438c2a46ab962e032.tar.gz | |
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>
Diffstat (limited to 'arch/riscv/kernel/machine_kexec.c')
| -rw-r--r-- | arch/riscv/kernel/machine_kexec.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/riscv/kernel/machine_kexec.c b/arch/riscv/kernel/machine_kexec.c index cbef0fc73afa..df8e24559035 100644 --- a/arch/riscv/kernel/machine_kexec.c +++ b/arch/riscv/kernel/machine_kexec.c @@ -65,7 +65,9 @@ machine_kexec_prepare(struct kimage *image) if (image->segment[i].memsz <= sizeof(fdt)) continue; - if (copy_from_user(&fdt, image->segment[i].buf, sizeof(fdt))) + if (image->file_mode) + memcpy(&fdt, image->segment[i].buf, sizeof(fdt)); + else if (copy_from_user(&fdt, image->segment[i].buf, sizeof(fdt))) continue; if (fdt_check_header(&fdt)) |