linux-kernel - Re: [PATCH] fork, memcg: fix cached

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 2 Jan 2019 21:23:48 +0100
From:   Michal Hocko <mhocko@...nel.org>
To:     Shakeel Butt <shakeelb@...gle.com>
Cc:     Rik van Riel <riel@...riel.com>, Roman Gushchin <guro@...com>,
        Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
        cgroups@...r.kernel.org, linux-kernel@...r.kernel.org,
        Johannes Weiner <hannes@...xchg.org>,
        Tejun Heo <tj@...nel.org>, stable@...r.kernel.org
Subject: Re: [PATCH] fork, memcg: fix cached_stacks case

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@...gle.com>
> Cc: Rik van Riel <riel@...riel.com>
> Cc: Roman Gushchin <guro@...com>
> Cc: Michal Hocko <mhocko@...e.com>
> Cc: Johannes Weiner <hannes@...xchg.org>
> Cc: Tejun Heo <tj@...nel.org>
> Cc: <stable@...r.kernel.org>

Ups, I have overlook that. Thanks for catching that.
Acked-by: Michal Hocko <mhocko@...e.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
> 

-- 
Michal Hocko
SUSE Labs