Commit 3ccea478 authored by Yanjun Yang's avatar Yanjun Yang Committed by Kees Cook
Browse files

ARM: Remove address checking for MMUless devices 



Commit 169f9102 ("ARM: 9350/1: fault: Implement
copy_from_kernel_nofault_allowed()") added the function to check address
before use. However, for devices without MMU, addr > TASK_SIZE will
always fail.  This patch move this function after the #ifdef CONFIG_MMU
statement.

Signed-off-by: default avatarYanjun Yang <yangyj.ee@gmail.com>
Acked-by: default avatarArd Biesheuvel <ardb@kernel.org>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218953
Fixes: 169f9102 ("ARM: 9350/1: fault: Implement copy_from_kernel_nofault_allowed()")
Link: https://lore.kernel.org/r/20240611100947.32241-1-yangyj.ee@gmail.com


Signed-off-by: default avatarKees Cook <kees@kernel.org>
parent 18c18b1f

arch/arm/mm/fault.c

+2 −2
Original line number Diff line number Diff line
@@ -25,6 +25,8 @@ 


#include "fault.h"



#ifdef CONFIG_MMU



bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)

{

	unsigned long addr = (unsigned long)unsafe_src;
@@ -32,8 +34,6 @@ bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size) 
	return addr >= TASK_SIZE && ULONG_MAX - addr >= size;

}



#ifdef CONFIG_MMU



/*

 * This is useful to dump out the page tables associated with

 * 'addr' in mm 'mm'.