diff options
| author | Atish Patra <atish.patra@wdc.com> | 2020-11-04 16:04:38 -0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmerdabbelt@google.com> | 2020-11-25 16:05:28 -0800 |
| commit | 19a00869028f4a28a36f90649166631dff6e3ccd (patch) | |
| tree | ef4a68e11c94a44d7e9de3f6f83fe57877739ba9 /arch/riscv/include | |
| parent | b6566dc1acca38ce6ed845ce8a270fb181ff6d41 (diff) | |
RISC-V: Protect all kernel sections including init early
Currently, .init.text & .init.data are intermixed which makes it impossible
apply different permissions to them. .init.data shouldn't need exec
permissions while .init.text shouldn't have write permission. Moreover,
the strict permission are only enforced /init starts. This leaves the
kernel vulnerable from possible buggy built-in modules.
Keep .init.text & .data in separate sections so that different permissions
are applied to each section. Apply permissions to individual sections as
early as possible. This improves the kernel protection under
CONFIG_STRICT_KERNEL_RWX. We also need to restore the permissions for the
entire _init section after it is freed so that those pages can be used
for other purpose.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv/include')
| -rw-r--r-- | arch/riscv/include/asm/sections.h | 2 | ||||
| -rw-r--r-- | arch/riscv/include/asm/set_memory.h | 4 |
2 files changed, 6 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/sections.h b/arch/riscv/include/asm/sections.h index 3a9971b1210f..1595c5b60cfd 100644 --- a/arch/riscv/include/asm/sections.h +++ b/arch/riscv/include/asm/sections.h @@ -9,5 +9,7 @@ extern char _start[]; extern char _start_kernel[]; +extern char __init_data_begin[], __init_data_end[]; +extern char __init_text_begin[], __init_text_end[]; #endif /* __ASM_SECTIONS_H */ diff --git a/arch/riscv/include/asm/set_memory.h b/arch/riscv/include/asm/set_memory.h index 4c5bae7ca01c..b21f4bea6434 100644 --- a/arch/riscv/include/asm/set_memory.h +++ b/arch/riscv/include/asm/set_memory.h @@ -15,11 +15,15 @@ int set_memory_ro(unsigned long addr, int numpages); int set_memory_rw(unsigned long addr, int numpages); int set_memory_x(unsigned long addr, int numpages); int set_memory_nx(unsigned long addr, int numpages); +int set_memory_rw_nx(unsigned long addr, int numpages); +void protect_kernel_text_data(void); #else static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; } static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; } static inline int set_memory_x(unsigned long addr, int numpages) { return 0; } static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; } +static inline void protect_kernel_text_data(void) {}; +static inline int set_memory_rw_nx(unsigned long addr, int numpages) { return 0; } #endif int set_direct_map_invalid_noflush(struct page *page); |