| Message ID | 20190102180145.57406-1-shakeelb@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fork, memcg: fix cached_stacks case | expand |
On Wed 02-01-19 10:01:45, Shakeel Butt wrote: > Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on > memcg charge fail") fixes a crash caused due to failed memcg charge of > the kernel stack. However the fix misses the cached_stacks case which > this patch fixes. So, the same crash can happen if the memcg charge of > a cached stack is failed. > > Fixes: 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on memcg charge fail") > Signed-off-by: Shakeel Butt <shakeelb@google.com> > Cc: Rik van Riel <riel@surriel.com> > Cc: Roman Gushchin <guro@fb.com> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Tejun Heo <tj@kernel.org> > Cc: <stable@vger.kernel.org> Ups, I have overlook that. Thanks for catching that. Acked-by: Michal Hocko <mhocko@suse.com> > --- > kernel/fork.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/fork.c b/kernel/fork.c > index e4a51124661a..593cd1577dff 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -216,6 +216,7 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) > memset(s->addr, 0, THREAD_SIZE); > > tsk->stack_vm_area = s; > + tsk->stack = s->addr; > return s->addr; > } > > -- > 2.20.1.415.g653613c723-goog >
On Wed, 2019-01-02 at 10:01 -0800, Shakeel Butt wrote: > Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on > memcg charge fail") fixes a crash caused due to failed memcg charge > of > the kernel stack. However the fix misses the cached_stacks case which > this patch fixes. So, the same crash can happen if the memcg charge > of > a cached stack is failed. > > Fixes: 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on > memcg charge fail") > Signed-off-by: Shakeel Butt <shakeelb@google.com> > Cc: Rik van Riel <riel@surriel.com> > Cc: Roman Gushchin <guro@fb.com> > Cc: Michal Hocko <mhocko@suse.com> > Cc: Johannes Weiner <hannes@cmpxchg.org> > Cc: Tejun Heo <tj@kernel.org> > Cc: <stable@vger.kernel.org> Good catch. Thank you. Acked-by: Rik van Riel <riel@surriel.com>
diff --git a/kernel/fork.c b/kernel/fork.c index e4a51124661a..593cd1577dff 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -216,6 +216,7 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) memset(s->addr, 0, THREAD_SIZE); tsk->stack_vm_area = s; + tsk->stack = s->addr; return s->addr; }
Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on memcg charge fail") fixes a crash caused due to failed memcg charge of the kernel stack. However the fix misses the cached_stacks case which this patch fixes. So, the same crash can happen if the memcg charge of a cached stack is failed. Fixes: 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on memcg charge fail") Signed-off-by: Shakeel Butt <shakeelb@google.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <guro@fb.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> --- kernel/fork.c | 1 + 1 file changed, 1 insertion(+)