diff options
| author | Liao Chang <liaochang1@huawei.com> | 2022-04-08 18:09:10 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-14 18:41:28 +0200 |
| commit | 3ca8a07f141fd8eec347a82bdfa4b94164f2bb97 (patch) | |
| tree | 9acfd1e547aa7ac6428b1f39d2b52216b46c4a80 | |
| parent | 0b26fd8ea5a0639acaf7c670ae69c903a08fb101 (diff) | |
RISC-V: use memcpy for kexec_file mode
[ Upstream commit b7fb4d78a6ade6026d9e5cf438c2a46ab962e032 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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)) |