From c15b5c6fabcbfcde904c157fd34043d055617996 Mon Sep 17 00:00:00 2001 From: Jiantao Shan Date: Wed, 24 Apr 2024 12:36:07 +0800 Subject: [PATCH] LoongArch: Fix access error when read fault on a write-only VMA commit efb44ff64c95340b06331fc48634b99efc9dd77c upstream. As with most architectures, allow handling of read faults in VMAs that have VM_WRITE but without VM_READ (WRITE implies READ). Otherwise, reading before writing a write-only memory will error while reading after writing everything is fine. BTW, move the VM_EXEC judgement before VM_READ/VM_WRITE to make logic a little clearer. Cc: stable@vger.kernel.org Fixes: 09cfefb7fa70c3af01 ("LoongArch: Add memory management") Signed-off-by: Jiantao Shan Signed-off-by: Huacai Chen Signed-off-by: Greg Kroah-Hartman --- arch/loongarch/mm/fault.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c index 1fc2f6813ea0..97b40defde06 100644 --- a/arch/loongarch/mm/fault.c +++ b/arch/loongarch/mm/fault.c @@ -202,10 +202,10 @@ good_area: if (!(vma->vm_flags & VM_WRITE)) goto bad_area; } else { - if (!(vma->vm_flags & VM_READ) && address != exception_era(regs)) - goto bad_area; if (!(vma->vm_flags & VM_EXEC) && address == exception_era(regs)) goto bad_area; + if (!(vma->vm_flags & (VM_READ | VM_WRITE)) && address != exception_era(regs)) + goto bad_area; } /*