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From: Muchun Song In-Reply-To: <20241011142105.391157-1-chenridong@huaweicloud.com> Date: Sat, 12 Oct 2024 10:42:52 +0800 Cc: akpm@linux-foundation.org, david@fromorbit.com, zhengqi.arch@bytedance.com, roman.gushchin@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, chenridong@huawei.com, wangweiyang2@huawei.com Content-Transfer-Encoding: quoted-printable Message-Id: <63593DC0-21DD-40C1-A4D8-6082F2BB4222@linux.dev> References: <20241011142105.391157-1-chenridong@huaweicloud.com> To: Chen Ridong X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam03 X-Rspam-User: X-Rspamd-Queue-Id: 69E95120005 X-Stat-Signature: 6k6mgdhtshhjuhtzabgzht1qo4zzdycr X-HE-Tag: 1728701018-175641 X-HE-Meta: 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 E8ilAhdo KC1kTJfeyLQGxjcF1Q1Rm1mDgtuesDS6yUyH/UaFF+s76ZBOZsGLgvSuxz6cybO/FZxlupkkLp5wX8uhs2Ui1FF7oW7sDW7wexnhIHCt6IDM6uZfjzZ27FSXvKjekCna6i/cVX9Dom/LHhmZrjqhDkA4H748kk3ANaR4+XNX6VOVVl+xTAsLNA4lcNLiPT11ei1TiG6C1pI5QmjRPrL3jqrr1i1w3rvVSOB2LFVkEzM6a4TMltGxMWKkRcrJkjrvrEfpHvHnTxtA7URs= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Oct 11, 2024, at 22:21, Chen Ridong = wrote: >=20 > From: Chen Ridong >=20 > A memleak was found as bellow: >=20 > 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): > [] __kmalloc_node_noprof+0x394/0x470 > [] alloc_shrinker_info+0x7b/0x1a0 > [] mem_cgroup_css_online+0x11a/0x3b0 > [] online_css+0x29/0xa0 > [] cgroup_apply_control_enable+0x20d/0x360 > [] cgroup_mkdir+0x168/0x5f0 > [] kernfs_iop_mkdir+0x5e/0x90 > [] vfs_mkdir+0x144/0x220 > [] do_mkdirat+0x87/0x130 > [] __x64_sys_mkdir+0x49/0x70 > [] do_syscall_64+0x68/0x140 > [] entry_SYSCALL_64_after_hwframe+0x76/0x7e >=20 > In the alloc_shrinker_info function, when shrinker_unit_alloc return > err, the info won't be freed. Just fix it. >=20 > Fixes: 307bececcd12 ("mm: shrinker: add a secondary array for = shrinker_info::{map, nr_deferred}") > Signed-off-by: Chen Ridong > --- > mm/shrinker.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) >=20 > 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 =3D 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); > --=20 > 2.34.1 >=20