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: c36e202495 ("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>
This commit is contained in:
Miaohe Lin 2022-08-23 11:23:44 +08:00 committed by Andrew Morton
parent 12f1dbcf8f
commit 54f9555d40

View file

@ -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);
}