Björn Töpel 6fdd5d2f8c riscv: mm: Proper page permissions after initmem free ... 64-bit RISC-V kernels have the kernel image mapped separately to alias the linear map. The linear map and the kernel image map are documented as "direct mapping" and "kernel" respectively in [1]. At image load time, the linear map corresponding to the kernel image is set to PAGE_READ permission, and the kernel image map is set to PAGE_READ|PAGE_EXEC. When the initmem is freed, the pages in the linear map should be restored to PAGE_READ|PAGE_WRITE, whereas the corresponding pages in the kernel image map should be restored to PAGE_READ, by removing the PAGE_EXEC permission. This is not the case. For 64-bit kernels, only the linear map is restored to its proper page permissions at initmem free, and not the kernel image map. In practise this results in that the kernel can potentially jump to dead __init code, and start executing invalid instructions, without getting an exception. Restore the freed initmem properly, by setting both the kernel image map to the correct permissions. [1] Documentation/riscv/vm-layout.rst Fixes: e5c35fa040 ("riscv: Map the kernel with correct permissions the first time") Signed-off-by: Björn Töpel <bjorn@rivosinc.com> Reviewed-by: Alexandre Ghiti <alex@ghiti.fr> Tested-by: Alexandre Ghiti <alex@ghiti.fr> Link: https://lore.kernel.org/r/20221115090641.258476-1-bjorn@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>		2022-11-29 18:54:30 -08:00
..
boot	riscv: dts: sifive unleashed: Add PWM controlled LEDs	2022-10-28 15:27:42 -07:00
configs	riscv: enable CD-ROM file systems in defconfig	2022-08-25 17:01:09 -07:00
errata	Merge patch series "Some style cleanups for recent extension additions"	2022-10-13 08:46:31 -07:00
include	riscv: Sync efi page table's kernel mappings before switching	2022-11-28 16:36:34 -08:00
kernel	riscv: mm: Proper page permissions after initmem free	2022-11-29 18:54:30 -08:00
kvm	The first batch of KVM patches, mostly covering x86, which I	2022-10-09 09:39:55 -07:00
lib	riscv: lib: uaccess: fix CSR_STATUS SR_SUM bit	2022-08-10 14:06:31 -07:00
mm	riscv: fix reserved memory setup	2022-11-10 14:46:33 -08:00
net	bpf, riscv: Support riscv jit to provide bpf_line_info	2022-06-02 16:26:01 -07:00
purgatory	riscv/purgatory: Omit use of bin2c	2022-08-11 09:32:34 -07:00
Kbuild	riscv: move errata/ and kvm/ builds to arch/riscv/Kbuild	2022-06-01 22:26:32 -07:00
Kconfig	riscv: Fix NR_CPUS range conditions	2022-11-28 15:27:00 -08:00
Kconfig.debug
Kconfig.erratas	riscv: make t-head erratas depend on MMU	2022-09-17 01:48:22 -07:00
Kconfig.socs	riscv: Kconfig: Style cleanups	2022-06-30 19:26:16 -07:00
Makefile	Merge patch series "Fix RISC-V toolchain extension support detection"	2022-10-27 15:14:07 -07:00