Commit 26509034 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

m68k: fix access_ok for coldfire 



While most m68k platforms use separate address spaces for user
and kernel space, at least coldfire does not, and the other
ones have a TASK_SIZE that is less than the entire 4GB address
range.

Using the default implementation of __access_ok() stops coldfire
user space from trivially accessing kernel memory.

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 15f3d81a

arch/m68k/include/asm/uaccess.h

+9 −6
Original line number Diff line number Diff line
@@ -12,14 +12,17 @@ 
#include <asm/extable.h>



/* We let the MMU do all checking */

static inline int access_ok(const void __user *addr,

static inline int access_ok(const void __user *ptr,

			    unsigned long size)

{

	/*

	 * XXX: for !CONFIG_CPU_HAS_ADDRESS_SPACES this really needs to check

	 * for TASK_SIZE!

	 */

	unsigned long limit = TASK_SIZE;

	unsigned long addr = (unsigned long)ptr;



	if (IS_ENABLED(CONFIG_CPU_HAS_ADDRESS_SPACES) ||

	    !IS_ENABLED(CONFIG_MMU))

		return 1;



	return (size <= limit) && (addr <= (limit - size));

}



/*