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. Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Reported-by: syzbot+00d13e505ef530a45100@xxxxxxxxxxxxxxxxxxxxxxxxx Tested-by: syzbot+00d13e505ef530a45100@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- fs/efivarfs/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c index 09fcf731e65d..6eae8cf655c1 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; } -- 2.47.2
