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 <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: <[email protected]>
---
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 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 <[email protected]>
> Cc: Rik van Riel <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Tejun Heo <[email protected]>
> Cc: <[email protected]>
Ups, I have overlook that. Thanks for catching that.
Acked-by: Michal Hocko <[email protected]>
> ---
> 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
>
--
Michal Hocko
SUSE Labs
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 <[email protected]>
> Cc: Rik van Riel <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> Cc: Michal Hocko <[email protected]>
> Cc: Johannes Weiner <[email protected]>
> Cc: Tejun Heo <[email protected]>
> Cc: <[email protected]>
Good catch. Thank you.
Acked-by: Rik van Riel <[email protected]>
--
All Rights Reversed.