The patch titled
Subject: nilfs2: fix NULL pointer in nilfs_##name##_attr_release
has been added to the -mm tree. Its filename is
nilfs2-fix-null-pointer-in-nilfs_name_attr_release.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/nilfs2-fix-null-pointer-in-nilfs_name_attr_release.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/nilfs2-fix-null-pointer-in-nilfs_name_attr_release.patch
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------------------------------------------------------
From: Nanyong Sun <sunnanyong@xxxxxxxxxx>
Subject: nilfs2: fix NULL pointer in nilfs_##name##_attr_release
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@xxxxxxxxxx
Link: https://lkml.kernel.org/r/1625651306-10829-3-git-send-email-konishi.ryusuke@xxxxxxxxx
Signed-off-by: Nanyong Sun <sunnanyong@xxxxxxxxxx>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/nilfs2/sysfs.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
--- a/fs/nilfs2/sysfs.c~nilfs2-fix-null-pointer-in-nilfs_name_attr_release
+++ a/fs/nilfs2/sysfs.c
@@ -51,11 +51,9 @@ static const struct sysfs_ops nilfs_##na
#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 = { \
_
Patches currently in -mm which might be from sunnanyong@xxxxxxxxxx are
nilfs2-fix-memory-leak-in-nilfs_sysfs_create_device_group.patch
nilfs2-fix-null-pointer-in-nilfs_name_attr_release.patch
nilfs2-fix-memory-leak-in-nilfs_sysfs_create_name_group.patch
nilfs2-fix-memory-leak-in-nilfs_sysfs_delete_name_group.patch
nilfs2-fix-memory-leak-in-nilfs_sysfs_create_snapshot_group.patch
nilfs2-fix-memory-leak-in-nilfs_sysfs_delete_snapshot_group.patch
