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From: Muchun Song In-Reply-To: <20241014032336.482088-1-chenridong@huaweicloud.com> Date: Mon, 14 Oct 2024 14:25:04 +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: References: <20241014032336.482088-1-chenridong@huaweicloud.com> To: Chen Ridong X-Migadu-Flow: FLOW_OUT X-Stat-Signature: eridk9bpnth357jgr6m56e3an7nmi36n X-Rspamd-Queue-Id: 4AF1820008 X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1728887152-108395 X-HE-Meta: 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 Hb3ZA8Sj t02auauqcnwqiwSr4MfCpykKBDnTW3WxPFsZFelDNr9qISs5ytweoYsbDybAIq8/hhdiJBxLIRnw6/Zb9demVwzIa+JoKqYph2bTOx403qbw4tA3Q2UTDFfjlRhztqUlAvvNcQoA+IVvCIviQK1Rec7BPMuk6cpkm831oNfOfGrfrozJyYvwqTdLhW7GBa7oZ61HUUM5YUryPx5Y0ppQ4MR60ZTKWRjNQM9yK+KzCf0goMA64Cz3faywripUy7wvmrrzyU9p0WVS0ckw= 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 14, 2024, at 11:23, 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 | 1 + > 1 file changed, 1 insertion(+) >=20 > diff --git a/mm/shrinker.c b/mm/shrinker.c > index dc5d2a6fcfc4..92270413190d 100644 > --- a/mm/shrinker.c > +++ b/mm/shrinker.c > @@ -97,6 +97,7 @@ int alloc_shrinker_info(struct mem_cgroup *memcg) >=20 > err: > mutex_unlock(&shrinker_mutex); > + kvfree(info); Please transpose kvfree() to the place above mutex_unlock(). We should release the resources in the order which is inverse to the that of acquiring resources. Thanks. > free_shrinker_info(memcg); > return -ENOMEM; > } > --=20 > 2.34.1 >=20