Commit b868497e authored by Nanyong Sun's avatar Nanyong Sun Committed by Zheng Zengkai
Browse files

nilfs2: fix NULL pointer in nilfs_##name##_attr_release 

stable inclusion
from stable-5.10.69
commit 0480f7a480bccdd5e747e64365b703105ccae350
bugzilla: 182675 https://gitee.com/openeuler/kernel/issues/I4I3ED

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0480f7a480bccdd5e747e64365b703105ccae350

--------------------------------

[ Upstream commit dbc6e7d4 ]

In nilfs_##name##_attr_release, kobj->parent should not be referenced
because it is a NULL pointer.  The release() method of kobject is always
called in kobject_put(kobj), in the implementation of kobject_put(), the
kobj->parent will be assigned as NULL before call the release() method.
So just use kobj to get the subgroups, which is more efficient and can fix
a NULL pointer reference problem.

Link: https://lkml.kernel.org/r/20210629022556.3985106-3-sunnanyong@huawei.com
Link: https://lkml.kernel.org/r/1625651306-10829-3-git-send-email-konishi.ryusuke@gmail.com


Signed-off-by: default avatarNanyong Sun <sunnanyong@huawei.com>
Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
Signed-off-by: default avatarChen Jun <chenjun102@huawei.com>
Acked-by: default avatarWeilong Chen <chenweilong@huawei.com>

Signed-off-by: default avatarChen Jun <chenjun102@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent fe2934b9

fs/nilfs2/sysfs.c

+3 −5
Original line number Diff line number Diff line
@@ -64,11 +64,9 @@ static const struct sysfs_ops nilfs_##name##_attr_ops = { \ 
#define NILFS_DEV_INT_GROUP_TYPE(name, parent_name) \

static void nilfs_##name##_attr_release(struct kobject *kobj) \

{ \

	struct nilfs_sysfs_##parent_name##_subgroups *subgroups; \

	struct the_nilfs *nilfs = container_of(kobj->parent, \

						struct the_nilfs, \

						ns_##parent_name##_kobj); \

	subgroups = nilfs->ns_##parent_name##_subgroups; \

	struct nilfs_sysfs_##parent_name##_subgroups *subgroups = container_of(kobj, \

						struct nilfs_sysfs_##parent_name##_subgroups, \

						sg_##name##_kobj); \

	complete(&subgroups->sg_##name##_kobj_unregister); \

} \

static struct kobj_type nilfs_##name##_ktype = { \