From 54f9555d4031d4aeb10651aa9dcb5335f6a05865 Mon Sep 17 00:00:00 2001
From: Miaohe Lin <linmiaohe@huawei.com>
Date: Tue, 23 Aug 2022 11:23:44 +0800
Subject: [PATCH] mm, hwpoison: fix possible use-after-free in
mf_dax_kill_procs()
After kill_procs(), tk will be freed without being removed from the
to_kill list. In the next iteration, the freed list entry in the to_kill
list will be accessed, thus leading to use-after-free issue. Adding
list_del() in kill_procs() to fix the issue.
Link: https://lkml.kernel.org/r/20220823032346.4260-5-linmiaohe@huawei.com
Fixes: c36e20249571 ("mm: introduce mf_dax_kill_procs() for fsdax case")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/memory-failure.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 799176d3f5f76..208a0f85ef54f 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -413,7 +413,7 @@ static void kill_procs(struct list_head *to_kill, int forcekill, bool fail,
{
struct to_kill *tk, *next;
- list_for_each_entry_safe (tk, next, to_kill, nd) {
+ list_for_each_entry_safe(tk, next, to_kill, nd) {
if (forcekill) {
/*
* In case something went wrong with munmapping
@@ -437,6 +437,7 @@ static void kill_procs(struct list_head *to_kill, int forcekill, bool fail,
pr_err("%#lx: Cannot send advisory machine check signal to %s:%d\n",
pfn, tk->tsk->comm, tk->tsk->pid);
}
+ list_del(&tk->nd);
put_task_struct(tk->tsk);
kfree(tk);
}
--
2.30.2