[PATCH v2] f2fs: add sanity check for proc_mkdir

From: Yangtao Li
Date: Tue Apr 25 2023 - 12:06:34 EST


Return -ENOMEM when proc_mkdir failed.

Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
v2:
-removing check for proc in f2fs_unregister_sysfs and f2fs_register_sysfs
fs/f2fs/sysfs.c | 39 +++++++++++++++++++++++----------------
1 file changed, 23 insertions(+), 16 deletions(-)

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 8ea05340bad9..467d743c801f 100644
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -1386,12 +1386,19 @@ int __init f2fs_init_sysfs(void)

ret = kobject_init_and_add(&f2fs_feat, &f2fs_feat_ktype,
NULL, "features");
- if (ret) {
- kobject_put(&f2fs_feat);
- kset_unregister(&f2fs_kset);
- } else {
- f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
+ if (ret)
+ goto put_kobject;
+
+ f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
+ if (!f2fs_proc_root) {
+ ret = -ENOMEM;
+ goto put_kobject;
}
+
+ return 0;
+put_kobject:
+ kobject_put(&f2fs_feat);
+ kset_unregister(&f2fs_kset);
return ret;
}

@@ -1430,23 +1437,24 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi)
if (err)
goto put_feature_list_kobj;

- if (f2fs_proc_root)
- sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
+ sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
+ if (!sbi->s_proc) {
+ err = -ENOMEM;
+ goto put_feature_list_kobj;
+ }

- if (sbi->s_proc) {
- proc_create_single_data("segment_info", 0444, sbi->s_proc,
+ proc_create_single_data("segment_info", 0444, sbi->s_proc,
segment_info_seq_show, sb);
- proc_create_single_data("segment_bits", 0444, sbi->s_proc,
+ proc_create_single_data("segment_bits", 0444, sbi->s_proc,
segment_bits_seq_show, sb);
#ifdef CONFIG_F2FS_IOSTAT
- proc_create_single_data("iostat_info", 0444, sbi->s_proc,
+ proc_create_single_data("iostat_info", 0444, sbi->s_proc,
iostat_info_seq_show, sb);
#endif
- proc_create_single_data("victim_bits", 0444, sbi->s_proc,
+ proc_create_single_data("victim_bits", 0444, sbi->s_proc,
victim_bits_seq_show, sb);
- proc_create_single_data("discard_plist_info", 0444, sbi->s_proc,
+ proc_create_single_data("discard_plist_info", 0444, sbi->s_proc,
discard_plist_seq_show, sb);
- }
return 0;
put_feature_list_kobj:
kobject_put(&sbi->s_feature_list_kobj);
@@ -1462,8 +1470,7 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi)

void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi)
{
- if (sbi->s_proc)
- remove_proc_subtree(sbi->sb->s_id, f2fs_proc_root);
+ remove_proc_subtree(sbi->sb->s_id, f2fs_proc_root);

kobject_put(&sbi->s_stat_kobj);
wait_for_completion(&sbi->s_stat_kobj_unregister);
--
2.39.0