From: Kent Overstreet Date: Sun, 19 May 2024 23:16:22 +0000 (-0400) Subject: bcachefs: Add missing guard in bch2_snapshot_has_children() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6d48e61364aedd774d688f28b5a6c9b5f7f0018c;p=linux.git 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 --- diff --git a/fs/bcachefs/snapshot.h b/fs/bcachefs/snapshot.h index bd5d74269d15a..ab13d8f4b41e1 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;