| Message ID | 20220823032346.4260-5-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | A few fixup patches for memory-failure | expand |
On Tue, Aug 23, 2022 at 11:23:44AM +0800, Miaohe Lin wrote: > 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. > > Fixes: c36e20249571 ("mm: introduce mf_dax_kill_procs() for fsdax case") > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Thank you for the update. Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> > --- > 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 1d79e693f1b9..f8262f577baf 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); > } > -- > 2.23.0
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 1d79e693f1b9..f8262f577baf 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); }
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. Fixes: c36e20249571 ("mm: introduce mf_dax_kill_procs() for fsdax case") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/memory-failure.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)