* [PATCH] mm: shrinker: avoid memleak in alloc_shrinker_info
@ 2024-10-11 14:21 Chen Ridong
2024-10-12 2:16 ` Qi Zheng
2024-10-12 2:42 ` Muchun Song
0 siblings, 2 replies; 4+ messages in thread
From: Chen Ridong @ 2024-10-11 14:21 UTC (permalink / raw)
To: akpm, david, zhengqi.arch, roman.gushchin, muchun.song
Cc: linux-mm, linux-kernel, chenridong, wangweiyang2
From: Chen Ridong <chenridong@huawei.com>
A memleak was found as bellow:
unreferenced object 0xffff8881010d2a80 (size 32):
comm "mkdir", pid 1559, jiffies 4294932666
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 @...............
backtrace (crc 2e7ef6fa):
[<ffffffff81372754>] __kmalloc_node_noprof+0x394/0x470
[<ffffffff813024ab>] alloc_shrinker_info+0x7b/0x1a0
[<ffffffff813b526a>] mem_cgroup_css_online+0x11a/0x3b0
[<ffffffff81198dd9>] online_css+0x29/0xa0
[<ffffffff811a243d>] cgroup_apply_control_enable+0x20d/0x360
[<ffffffff811a5728>] cgroup_mkdir+0x168/0x5f0
[<ffffffff8148543e>] kernfs_iop_mkdir+0x5e/0x90
[<ffffffff813dbb24>] vfs_mkdir+0x144/0x220
[<ffffffff813e1c97>] do_mkdirat+0x87/0x130
[<ffffffff813e1de9>] __x64_sys_mkdir+0x49/0x70
[<ffffffff81f8c928>] do_syscall_64+0x68/0x140
[<ffffffff8200012f>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
In the alloc_shrinker_info function, when shrinker_unit_alloc return
err, the info won't be freed. Just fix it.
Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}")
Signed-off-by: Chen Ridong <chenridong@huawei.com>
---
mm/shrinker.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/shrinker.c b/mm/shrinker.c
index dc5d2a6fcfc4..e4b795ee6d2e 100644
--- a/mm/shrinker.c
+++ b/mm/shrinker.c
@@ -87,8 +87,10 @@ int alloc_shrinker_info(struct mem_cgroup *memcg)
if (!info)
goto err;
info->map_nr_max = shrinker_nr_max;
- if (shrinker_unit_alloc(info, NULL, nid))
+ if (shrinker_unit_alloc(info, NULL, nid)) {
+ kvfree(info);
goto err;
+ }
rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info);
}
mutex_unlock(&shrinker_mutex);
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH] mm: shrinker: avoid memleak in alloc_shrinker_info
2024-10-11 14:21 [PATCH] mm: shrinker: avoid memleak in alloc_shrinker_info Chen Ridong
@ 2024-10-12 2:16 ` Qi Zheng
2024-10-12 2:42 ` Muchun Song
1 sibling, 0 replies; 4+ messages in thread
From: Qi Zheng @ 2024-10-12 2:16 UTC (permalink / raw)
To: Chen Ridong
Cc: akpm, david, roman.gushchin, muchun.song, linux-mm, linux-kernel,
chenridong, wangweiyang2
On 2024/10/11 22:21, Chen Ridong wrote:
> From: Chen Ridong <chenridong@huawei.com>
>
> A memleak was found as bellow:
>
> unreferenced object 0xffff8881010d2a80 (size 32):
> comm "mkdir", pid 1559, jiffies 4294932666
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 @...............
> backtrace (crc 2e7ef6fa):
> [<ffffffff81372754>] __kmalloc_node_noprof+0x394/0x470
> [<ffffffff813024ab>] alloc_shrinker_info+0x7b/0x1a0
> [<ffffffff813b526a>] mem_cgroup_css_online+0x11a/0x3b0
> [<ffffffff81198dd9>] online_css+0x29/0xa0
> [<ffffffff811a243d>] cgroup_apply_control_enable+0x20d/0x360
> [<ffffffff811a5728>] cgroup_mkdir+0x168/0x5f0
> [<ffffffff8148543e>] kernfs_iop_mkdir+0x5e/0x90
> [<ffffffff813dbb24>] vfs_mkdir+0x144/0x220
> [<ffffffff813e1c97>] do_mkdirat+0x87/0x130
> [<ffffffff813e1de9>] __x64_sys_mkdir+0x49/0x70
> [<ffffffff81f8c928>] do_syscall_64+0x68/0x140
> [<ffffffff8200012f>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
>
> In the alloc_shrinker_info function, when shrinker_unit_alloc return
> err, the info won't be freed. Just fix it.
>
> Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}")
I think this also needs to be cc'd to the stable mailing list:
Cc: stable@vger.kernel.org
> Signed-off-by: Chen Ridong <chenridong@huawei.com>
> ---
> mm/shrinker.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
Other than that, LGTM.
Acked-by: Qi Zheng <zhengqi.arch@bytedance.com>
Thanks!
>
> diff --git a/mm/shrinker.c b/mm/shrinker.c
> index dc5d2a6fcfc4..e4b795ee6d2e 100644
> --- a/mm/shrinker.c
> +++ b/mm/shrinker.c
> @@ -87,8 +87,10 @@ int alloc_shrinker_info(struct mem_cgroup *memcg)
> if (!info)
> goto err;
> info->map_nr_max = shrinker_nr_max;
> - if (shrinker_unit_alloc(info, NULL, nid))
> + if (shrinker_unit_alloc(info, NULL, nid)) {
> + kvfree(info);
> goto err;
> + }
> rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info);
> }
> mutex_unlock(&shrinker_mutex);
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm: shrinker: avoid memleak in alloc_shrinker_info
2024-10-11 14:21 [PATCH] mm: shrinker: avoid memleak in alloc_shrinker_info Chen Ridong
2024-10-12 2:16 ` Qi Zheng
@ 2024-10-12 2:42 ` Muchun Song
2024-10-14 0:47 ` chenridong
1 sibling, 1 reply; 4+ messages in thread
From: Muchun Song @ 2024-10-12 2:42 UTC (permalink / raw)
To: Chen Ridong
Cc: akpm, david, zhengqi.arch, roman.gushchin, linux-mm, linux-kernel,
chenridong, wangweiyang2
> On Oct 11, 2024, at 22:21, Chen Ridong <chenridong@huaweicloud.com> wrote:
>
> From: Chen Ridong <chenridong@huawei.com>
>
> A memleak was found as bellow:
>
> unreferenced object 0xffff8881010d2a80 (size 32):
> comm "mkdir", pid 1559, jiffies 4294932666
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 @...............
> backtrace (crc 2e7ef6fa):
> [<ffffffff81372754>] __kmalloc_node_noprof+0x394/0x470
> [<ffffffff813024ab>] alloc_shrinker_info+0x7b/0x1a0
> [<ffffffff813b526a>] mem_cgroup_css_online+0x11a/0x3b0
> [<ffffffff81198dd9>] online_css+0x29/0xa0
> [<ffffffff811a243d>] cgroup_apply_control_enable+0x20d/0x360
> [<ffffffff811a5728>] cgroup_mkdir+0x168/0x5f0
> [<ffffffff8148543e>] kernfs_iop_mkdir+0x5e/0x90
> [<ffffffff813dbb24>] vfs_mkdir+0x144/0x220
> [<ffffffff813e1c97>] do_mkdirat+0x87/0x130
> [<ffffffff813e1de9>] __x64_sys_mkdir+0x49/0x70
> [<ffffffff81f8c928>] do_syscall_64+0x68/0x140
> [<ffffffff8200012f>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
>
> In the alloc_shrinker_info function, when shrinker_unit_alloc return
> err, the info won't be freed. Just fix it.
>
> Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}")
> Signed-off-by: Chen Ridong <chenridong@huawei.com>
> ---
> mm/shrinker.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/shrinker.c b/mm/shrinker.c
> index dc5d2a6fcfc4..e4b795ee6d2e 100644
> --- a/mm/shrinker.c
> +++ b/mm/shrinker.c
> @@ -87,8 +87,10 @@ int alloc_shrinker_info(struct mem_cgroup *memcg)
> if (!info)
> goto err;
> info->map_nr_max = shrinker_nr_max;
> - if (shrinker_unit_alloc(info, NULL, nid))
> + if (shrinker_unit_alloc(info, NULL, nid)) {
> + kvfree(info);
> goto err;
Since we already use goto to do the cleanup for failure, I don't like
to mix two different ways to do the similar thing. I suggest adding
the kvfree (BTW, it could handle NULL argument) to the label of err.
Muchun,
Thanks.
> + }
> rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info);
> }
> mutex_unlock(&shrinker_mutex);
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm: shrinker: avoid memleak in alloc_shrinker_info
2024-10-12 2:42 ` Muchun Song
@ 2024-10-14 0:47 ` chenridong
0 siblings, 0 replies; 4+ messages in thread
From: chenridong @ 2024-10-14 0:47 UTC (permalink / raw)
To: Muchun Song, Chen Ridong
Cc: akpm, david, zhengqi.arch, roman.gushchin, linux-mm, linux-kernel,
wangweiyang2
On 2024/10/12 10:42, Muchun Song wrote:
>
>
>> On Oct 11, 2024, at 22:21, Chen Ridong <chenridong@huaweicloud.com> wrote:
>>
>> From: Chen Ridong <chenridong@huawei.com>
>>
>> A memleak was found as bellow:
>>
>> unreferenced object 0xffff8881010d2a80 (size 32):
>> comm "mkdir", pid 1559, jiffies 4294932666
>> hex dump (first 32 bytes):
>> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
>> 40 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 @...............
>> backtrace (crc 2e7ef6fa):
>> [<ffffffff81372754>] __kmalloc_node_noprof+0x394/0x470
>> [<ffffffff813024ab>] alloc_shrinker_info+0x7b/0x1a0
>> [<ffffffff813b526a>] mem_cgroup_css_online+0x11a/0x3b0
>> [<ffffffff81198dd9>] online_css+0x29/0xa0
>> [<ffffffff811a243d>] cgroup_apply_control_enable+0x20d/0x360
>> [<ffffffff811a5728>] cgroup_mkdir+0x168/0x5f0
>> [<ffffffff8148543e>] kernfs_iop_mkdir+0x5e/0x90
>> [<ffffffff813dbb24>] vfs_mkdir+0x144/0x220
>> [<ffffffff813e1c97>] do_mkdirat+0x87/0x130
>> [<ffffffff813e1de9>] __x64_sys_mkdir+0x49/0x70
>> [<ffffffff81f8c928>] do_syscall_64+0x68/0x140
>> [<ffffffff8200012f>] entry_SYSCALL_64_after_hwframe+0x76/0x7e
>>
>> In the alloc_shrinker_info function, when shrinker_unit_alloc return
>> err, the info won't be freed. Just fix it.
>>
>> Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for shrinker_info::{map, nr_deferred}")
>> Signed-off-by: Chen Ridong <chenridong@huawei.com>
>> ---
>> mm/shrinker.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/mm/shrinker.c b/mm/shrinker.c
>> index dc5d2a6fcfc4..e4b795ee6d2e 100644
>> --- a/mm/shrinker.c
>> +++ b/mm/shrinker.c
>> @@ -87,8 +87,10 @@ int alloc_shrinker_info(struct mem_cgroup *memcg)
>> if (!info)
>> goto err;
>> info->map_nr_max = shrinker_nr_max;
>> - if (shrinker_unit_alloc(info, NULL, nid))
>> + if (shrinker_unit_alloc(info, NULL, nid)) {
>> + kvfree(info);
>> goto err;
>
> Since we already use goto to do the cleanup for failure, I don't like
> to mix two different ways to do the similar thing. I suggest adding
> the kvfree (BTW, it could handle NULL argument) to the label of err.
>
> Muchun,
> Thanks.
>
Thanks, I will update soon.
Best regards,
Ridong
>> + }
>> rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info);
>> }
>> mutex_unlock(&shrinker_mutex);
>> --
>> 2.34.1
>>
>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2024-10-14 0:48 UTC | newest]
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2024-10-11 14:21 [PATCH] mm: shrinker: avoid memleak in alloc_shrinker_info Chen Ridong
2024-10-12 2:16 ` Qi Zheng
2024-10-12 2:42 ` Muchun Song
2024-10-14 0:47 ` chenridong
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