Re: [syzbot ci] Re: Implement a new generic pagewalk API

["Oscar Salvador (SUSE)" <osalvador@kernel.org>]

[-- Attachment #1: Type: text/plain, Size: 999 bytes --]

On Mon, May 25, 2026 at 10:49:28PM -0700, syzbot ci wrote:
> syzbot ci has tested the following series
> 
> [v3] Implement a new generic pagewalk API
> https://lore.kernel.org/all/20260525165528.184397-1-osalvador@suse.de
> * [RFC PATCH v3 1/8] mm: Add softleaf_from_pud
> * [RFC PATCH v3 2/8] mm: Add {pmd,pud}_huge_lock helper
> * [RFC PATCH v3 3/8] mm: Implement folio_pmd_batch
> * [RFC PATCH v3 4/8] mm: Implement pt_range_walk
> * [RFC PATCH v3 5/8] mm: Make /proc/pid/smaps use the new generic pagewalk API
> * [RFC PATCH v3 6/8] mm: Make /proc/pid/numa_maps use the new generic pagewalk API
> * [RFC PATCH v3 7/8] mm: Make /proc/pid/pagemap use the new generic pagewalk API
> * [RFC PATCH v3 8/8] mm: Make /proc/pid/clear_refs use the new generic pagewalk API
> 
> and found the following issue:
> general protection fault in clear_refs_write
> 
> Full report is available here:
> https://ci.syzbot.org/series/0beab2d0-9d88-4288-ac81-b294e51c057d

#syz test

 

-- 
Oscar Salvador
SUSE Labs

[-- Attachment #2: 0001-fix.patch --]
[-- Type: text/x-patch, Size: 668 bytes --]

From 59776435d1beca2bd9446050450afe04453a99e8 Mon Sep 17 00:00:00 2001
From: Oscar Salvador <osalvador@suse.de>
Date: Thu, 11 Jun 2026 13:58:44 +0200
Subject: [PATCH] fix

---
 fs/proc/task_mmu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 1134dfb3dab0..fadc6356f84e 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1710,6 +1710,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
 			else if (ret < 0)
 				break;
 
+			flags &= ~PT_TYPE_NONE;
 			pt_type = pt_range_walk_start(&ptw, vma, vma->vm_start, vma->vm_end, flags);
 			while (pt_type != PTW_DONE) {
 
-- 
2.35.3