f2fs: fix uninitialized kobject put in f2fs_init_sysfs()

In f2fs_init_sysfs(), all failure paths after kset_register() jump to
put_kobject, which unconditionally releases both f2fs_tune and
f2fs_feat.

If kobject_init_and_add(&f2fs_feat, ...) fails, f2fs_tune has not been
initialized yet, so calling kobject_put(&f2fs_tune) is invalid.

Fix this by splitting the unwind path so each error path only releases
objects that were successfully initialized.

Fixes: a907f3a68ee26ba4 ("f2fs: add a sysfs entry to reclaim POSIX_FADV_NOREUSE pages")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
index 12993ae1713b0ad99e67e226cfe96d9ed0818ec4..352e96ad5c3a561091364f03b16de23685f67a24 100644 (file)
--- a/fs/f2fs/sysfs.c
+++ b/fs/f2fs/sysfs.c
@@ -1997,24 +1997,26 @@ int __init f2fs_init_sysfs(void)
        ret = kobject_init_and_add(&f2fs_feat, &f2fs_feat_ktype,
                                   NULL, "features");
        if (ret)
-               goto put_kobject;
+               goto unregister_kset;
 
        ret = kobject_init_and_add(&f2fs_tune, &f2fs_tune_ktype,
                                   NULL, "tuning");
        if (ret)
-               goto put_kobject;
+               goto put_feat;
 
        f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
        if (!f2fs_proc_root) {
                ret = -ENOMEM;
-               goto put_kobject;
+               goto put_tune;
        }
 
        return 0;
 
-put_kobject:
+put_tune:
        kobject_put(&f2fs_tune);
+put_feat:
        kobject_put(&f2fs_feat);
+unregister_kset:
        kset_unregister(&f2fs_kset);
        return ret;
 }