From 6d48e61364aedd774d688f28b5a6c9b5f7f0018c Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sun, 19 May 2024 19:16:22 -0400 Subject: bcachefs: Add missing guard in bch2_snapshot_has_children() We additionally need to be going inconsistent if passed an invalid snapshot ID; that patch will need more thorough testing. Reported-by: syzbot+1c9fca23fe478633b305@syzkaller.appspotmail.com Signed-off-by: Kent Overstreet --- fs/bcachefs/snapshot.h | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'fs') diff --git a/fs/bcachefs/snapshot.h b/fs/bcachefs/snapshot.h index bd5d74269d15..ab13d8f4b41e 100644 --- a/fs/bcachefs/snapshot.h +++ b/fs/bcachefs/snapshot.h @@ -176,12 +176,9 @@ static inline bool bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ances static inline bool bch2_snapshot_has_children(struct bch_fs *c, u32 id) { - const struct snapshot_t *t; - bool ret; - rcu_read_lock(); - t = snapshot_t(c, id); - ret = (t->children[0]|t->children[1]) != 0; + const struct snapshot_t *t = snapshot_t(c, id); + bool ret = t && (t->children[0]|t->children[1]) != 0; rcu_read_unlock(); return ret; -- cgit v1.2.3