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(+)
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; }
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;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
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Michal Hocko -
Rik van Riel -
Shakeel Butt