From: Ard Biesheuvel Date: Sun, 23 Feb 2025 15:48:54 +0000 (+0100) Subject: efivarfs: Defer PM notifier registration until .fill_super X-Git-Tag: v6.14-rc5~21^2~3 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cb6ae457bc6af58c84a7854df5e7e32ba1c6a715;p=thirdparty%2Flinux.git efivarfs: Defer PM notifier registration until .fill_super syzbot reports an issue that turns out to be caused by the fact that the efivarfs PM notifier may be invoked before the efivarfs_fs_info::sb field is populated, resulting in a NULL deference. So defer the registration until efivarfs_fill_super() is invoked. Reported-by: syzbot+00d13e505ef530a45100@syzkaller.appspotmail.com Tested-by: syzbot+00d13e505ef530a45100@syzkaller.appspotmail.com Signed-off-by: Ard Biesheuvel --- diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c index 09fcf731e65d6..6eae8cf655c12 100644 --- a/fs/efivarfs/super.c +++ b/fs/efivarfs/super.c @@ -367,6 +367,8 @@ static int efivarfs_fill_super(struct super_block *sb, struct fs_context *fc) if (err) return err; + register_pm_notifier(&sfi->pm_nb); + return efivar_init(efivarfs_callback, sb, true); } @@ -552,7 +554,6 @@ static int efivarfs_init_fs_context(struct fs_context *fc) sfi->pm_nb.notifier_call = efivarfs_pm_notify; sfi->pm_nb.priority = 0; - register_pm_notifier(&sfi->pm_nb); return 0; }