kernel.git/fs/nilfs2/sysfs.c, branch linux-6.15.y

nilfs2: protect references to superblock parameters exposed in sysfs

2024-09-02T00:59:00Z

The superblock buffers of nilfs2 can not only be overwritten at runtime for modifications/repairs, but they are also regularly swapped, replaced during resizing, and even abandoned when degrading to one side due to backing device issues. So, accessing them requires mutual exclusion using the reader/writer semaphore "nilfs->ns_sem". Some sysfs attribute show methods read this superblock buffer without the necessary mutual exclusion, which can cause problems with pointer dereferencing and memory access, so fix it. Link: https://lkml.kernel.org/r/20240811100320.9913-1-konishi.ryusuke@gmail.com Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/ group") Signed-off-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton

nilfs2: Constify struct kobj_type

2024-07-12T23:39:52Z

'struct kobj_type' is not modified in this driver. It is only used with kobject_init_and_add() which takes a "const struct kobj_type *" parameter. Constifying this structure moves some data to a read-only section, so increase overall security. On a x86_64, with allmodconfig: Before: ====== text data bss dec hex filename 22403 4184 24 26611 67f3 fs/nilfs2/sysfs.o After: ===== text data bss dec hex filename 22723 3928 24 26675 6833 fs/nilfs2/sysfs.o Link: https://lkml.kernel.org/r/20240708143242.3296-1-konishi.ryusuke@gmail.com Signed-off-by: Christophe JAILLET Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton

nilfs2: use default_groups in kobj_type

2021-12-29T09:53:48Z

There are currently 2 ways to create a set of sysfs files for a kobj_type, through the default_attrs field, and the default_groups field. Move the nilfs2 code to use default_groups field which has been the preferred way since aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") so that we can soon get rid of the obsolete default_attrs field. Acked-by: Ryusuke Konishi Link: https://lore.kernel.org/r/20211228144252.390554-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

nilfs2: remove filenames from file comments

2021-11-09T18:02:52Z

Remove filenames that are not particularly useful in file comments, and suppress checkpatch warnings WARNING: It's generally not useful to have the filename in the file Link: https://lkml.kernel.org/r/1635151862-11547-3-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Cc: Qing Wang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: replace snprintf in show functions with sysfs_emit

2021-11-09T18:02:51Z

Patch series "nilfs2 updates". This patch (of 2): coccicheck complains about the use of snprintf() in sysfs show functions. Fix the coccicheck warning: WARNING: use scnprintf or sprintf. Use sysfs_emit instead of scnprintf or sprintf makes more sense. Link: https://lkml.kernel.org/r/1635151862-11547-1-git-send-email-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/1634095759-4625-1-git-send-email-wangqing@vivo.com Link: https://lkml.kernel.org/r/1635151862-11547-2-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Qing Wang Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group

2021-09-08T18:50:27Z

kobject_put() should be used to cleanup the memory associated with the kobject instead of kobject_del(). See the section "Kobject removal" of "Documentation/core-api/kobject.rst". Link: https://lkml.kernel.org/r/20210629022556.3985106-7-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-7-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group

2021-09-08T18:50:27Z

If kobject_init_and_add returns with error, kobject_put() is needed here to avoid memory leak, because kobject_init_and_add may return error without freeing the memory associated with the kobject it allocated. Link: https://lkml.kernel.org/r/20210629022556.3985106-6-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-6-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group

2021-09-08T18:50:27Z

The kobject_put() should be used to cleanup the memory associated with the kobject instead of kobject_del. See the section "Kobject removal" of "Documentation/core-api/kobject.rst". Link: https://lkml.kernel.org/r/20210629022556.3985106-5-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-5-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group

2021-09-08T18:50:27Z

If kobject_init_and_add return with error, kobject_put() is needed here to avoid memory leak, because kobject_init_and_add may return error without freeing the memory associated with the kobject it allocated. Link: https://lkml.kernel.org/r/20210629022556.3985106-4-sunnanyong@huawei.com Link: https://lkml.kernel.org/r/1625651306-10829-4-git-send-email-konishi.ryusuke@gmail.com Signed-off-by: Nanyong Sun Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

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

2021-09-08T18:50:27Z

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: Nanyong Sun Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds