From a994402bc4714cefea5770b2d906cef5b0f4dc5c Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Tue, 22 Mar 2022 14:44:15 -0700 Subject: [PATCH] mm/memory-failure.c: catch unexpected -EFAULT from vma_address() It's unexpected to walk the page table when vma_address() return -EFAULT. But dev_pagemap_mapping_shift() is called only when vma associated to the error page is found already in collect_procs_{file,anon}, so vma_address() should not return -EFAULT except with some bug, as Naoya pointed out. We can use VM_BUG_ON_VMA() to catch this bug here. Link: https://lkml.kernel.org/r/20220218090118.1105-3-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Acked-by: Naoya Horiguchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory-failure.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 1e1cb1191ab7..b5291c86447f 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -315,6 +315,7 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page, pmd_t *pmd; pte_t *pte; + VM_BUG_ON_VMA(address == -EFAULT, vma); pgd = pgd_offset(vma->vm_mm, address); if (!pgd_present(*pgd)) return 0; -- 2.20.1