From: Kent Overstreet Date: Tue, 7 Nov 2023 15:30:22 +0000 (-0500) Subject: bcachefs: Fix null ptr deref in bch2_backpointer_get_node() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=03cc1e67a243cbb2c85d5fd84f369449f94d4269;p=linux.git bcachefs: Fix null ptr deref in bch2_backpointer_get_node() bch2_btree_iter_peek_node() can return a NULL ptr (when the tree is shorter than the search depth); handle this with an early return. Signed-off-by: Kent Overstreet Reported-by: Dan Carpenter Fixes: https://lore.kernel.org/linux-bcachefs/5fc3c28b-c232-4ec7-b0ac-4ef220ddf976@moroto.mountain/T/ Signed-off-by: Kent Overstreet --- diff --git a/fs/bcachefs/backpointers.c b/fs/bcachefs/backpointers.c index ef02c9bb03541..23c0834a97a4a 100644 --- a/fs/bcachefs/backpointers.c +++ b/fs/bcachefs/backpointers.c @@ -313,17 +313,17 @@ struct btree *bch2_backpointer_get_node(struct btree_trans *trans, bp.level - 1, 0); b = bch2_btree_iter_peek_node(iter); - if (IS_ERR(b)) + if (IS_ERR_OR_NULL(b)) goto err; BUG_ON(b->c.level != bp.level - 1); - if (b && extent_matches_bp(c, bp.btree_id, bp.level, - bkey_i_to_s_c(&b->key), - bucket, bp)) + if (extent_matches_bp(c, bp.btree_id, bp.level, + bkey_i_to_s_c(&b->key), + bucket, bp)) return b; - if (b && btree_node_will_make_reachable(b)) { + if (btree_node_will_make_reachable(b)) { b = ERR_PTR(-BCH_ERR_backpointer_to_overwritten_btree_node); } else { backpointer_not_found(trans, bp_pos, bp, bkey_i_to_s_c(&b->key));