* [patch] memcg: null dereference on allocation failure
@ 2010-10-28 11:12 Dan Carpenter
2010-10-28 15:52 ` Balbir Singh
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Dan Carpenter @ 2010-10-28 11:12 UTC (permalink / raw)
To: Balbir Singh
Cc: Daisuke Nishimura, KAMEZAWA Hiroyuki, linux-mm, linux-kernel,
kernel-janitors
The original code had a null dereference if alloc_percpu() failed.
This was introduced in 711d3d2c9bc3 "memcg: cpu hotplug aware percpu
count updates"
Signed-off-by: Dan Carpenter <error27@gmail.com>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9a99cfa..2efa8ea 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4208,15 +4208,17 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
memset(mem, 0, size);
mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
- if (!mem->stat) {
- if (size < PAGE_SIZE)
- kfree(mem);
- else
- vfree(mem);
- mem = NULL;
- }
+ if (!mem->stat)
+ goto out_free;
spin_lock_init(&mem->pcp_counter_lock);
return mem;
+
+out_free:
+ if (size < PAGE_SIZE)
+ kfree(mem);
+ else
+ vfree(mem);
+ return NULL;
}
/*
--
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [patch] memcg: null dereference on allocation failure
2010-10-28 11:12 [patch] memcg: null dereference on allocation failure Dan Carpenter
@ 2010-10-28 15:52 ` Balbir Singh
2010-10-28 23:39 ` KAMEZAWA Hiroyuki
2010-10-29 0:38 ` Daisuke Nishimura
2 siblings, 0 replies; 4+ messages in thread
From: Balbir Singh @ 2010-10-28 15:52 UTC (permalink / raw)
To: Dan Carpenter, Daisuke Nishimura, KAMEZAWA Hiroyuki, linux-mm,
linux-kernel, kernel-janitors
* Dan Carpenter <error27@gmail.com> [2010-10-28 13:12:41]:
> The original code had a null dereference if alloc_percpu() failed.
> This was introduced in 711d3d2c9bc3 "memcg: cpu hotplug aware percpu
> count updates"
>
> Signed-off-by: Dan Carpenter <error27@gmail.com>
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 9a99cfa..2efa8ea 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4208,15 +4208,17 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
>
> memset(mem, 0, size);
> mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
> - if (!mem->stat) {
> - if (size < PAGE_SIZE)
> - kfree(mem);
> - else
> - vfree(mem);
> - mem = NULL;
> - }
> + if (!mem->stat)
> + goto out_free;
> spin_lock_init(&mem->pcp_counter_lock);
> return mem;
> +
> +out_free:
> + if (size < PAGE_SIZE)
> + kfree(mem);
> + else
> + vfree(mem);
> + return NULL;
> }
Good catch!
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
--
Three Cheers,
Balbir
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [patch] memcg: null dereference on allocation failure
2010-10-28 11:12 [patch] memcg: null dereference on allocation failure Dan Carpenter
2010-10-28 15:52 ` Balbir Singh
@ 2010-10-28 23:39 ` KAMEZAWA Hiroyuki
2010-10-29 0:38 ` Daisuke Nishimura
2 siblings, 0 replies; 4+ messages in thread
From: KAMEZAWA Hiroyuki @ 2010-10-28 23:39 UTC (permalink / raw)
To: Dan Carpenter
Cc: Balbir Singh, Daisuke Nishimura, linux-mm, linux-kernel, kernel-janitors
On Thu, 28 Oct 2010 13:12:41 +0200
Dan Carpenter <error27@gmail.com> wrote:
> The original code had a null dereference if alloc_percpu() failed.
> This was introduced in 711d3d2c9bc3 "memcg: cpu hotplug aware percpu
> count updates"
>
> Signed-off-by: Dan Carpenter <error27@gmail.com>
Ah, my fault. Thank you for catching.
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [patch] memcg: null dereference on allocation failure
2010-10-28 11:12 [patch] memcg: null dereference on allocation failure Dan Carpenter
2010-10-28 15:52 ` Balbir Singh
2010-10-28 23:39 ` KAMEZAWA Hiroyuki
@ 2010-10-29 0:38 ` Daisuke Nishimura
2 siblings, 0 replies; 4+ messages in thread
From: Daisuke Nishimura @ 2010-10-29 0:38 UTC (permalink / raw)
To: Dan Carpenter
Cc: Andrew Morton, Balbir Singh, KAMEZAWA Hiroyuki, linux-mm,
linux-kernel, kernel-janitors, Daisuke Nishimura
(I add Andrew to CC-list)
On Thu, 28 Oct 2010 13:12:41 +0200
Dan Carpenter <error27@gmail.com> wrote:
> The original code had a null dereference if alloc_percpu() failed.
> This was introduced in 711d3d2c9bc3 "memcg: cpu hotplug aware percpu
> count updates"
>
> Signed-off-by: Dan Carpenter <error27@gmail.com>
>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 9a99cfa..2efa8ea 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4208,15 +4208,17 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
>
> memset(mem, 0, size);
> mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
> - if (!mem->stat) {
> - if (size < PAGE_SIZE)
> - kfree(mem);
> - else
> - vfree(mem);
> - mem = NULL;
> - }
> + if (!mem->stat)
> + goto out_free;
> spin_lock_init(&mem->pcp_counter_lock);
> return mem;
> +
> +out_free:
> + if (size < PAGE_SIZE)
> + kfree(mem);
> + else
> + vfree(mem);
> + return NULL;
> }
>
> /*
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^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-10-29 0:46 UTC | newest]
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2010-10-28 11:12 [patch] memcg: null dereference on allocation failure Dan Carpenter
2010-10-28 15:52 ` Balbir Singh
2010-10-28 23:39 ` KAMEZAWA Hiroyuki
2010-10-29 0:38 ` Daisuke Nishimura
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