5.4-stable review patch. If anyone has any objections, please let me know.
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From: Yanjun Yang yangyj.ee@gmail.com
commit 3ccea4784fddd96fbd6c4497eb28b45dab638c2a upstream.
Commit 169f9102f9198b ("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: Yanjun Yang yangyj.ee@gmail.com Acked-by: Ard Biesheuvel ardb@kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218953 Fixes: 169f9102f9198b ("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: Kees Cook kees@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm/mm/fault.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -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(co 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'.