From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Wed, 2 Apr 2025 16:48:23 +0000 (-0400)
Subject: bcachefs: Fix null ptr deref in invalidate_one_bucket()
X-Git-Tag: nvme-6.15-2025-04-10~18^2~2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=39ebd74864f5c4f7d44f1fe026c71a270631186b;p=nvme.git

bcachefs: Fix null ptr deref in invalidate_one_bucket()

bch2_backpointer_get_key() returns bkey_s_c_null when the target isn't
found.

backpointer_get_key() flags the error, so there's nothing else to do
here - just skip it and move on.

Link: https://github.com/koverstreet/bcachefs/issues/847
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---

diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c
index 6b6c2521c11f..94ea9e49aec4 100644
--- a/fs/bcachefs/alloc_background.c
+++ b/fs/bcachefs/alloc_background.c
@@ -2084,6 +2084,9 @@ static int invalidate_one_bp(struct btree_trans *trans,
 	if (ret)
 		return ret;
 
+	if (!extent_k.k)
+		return 0;
+
 	struct bkey_i *n =
 		bch2_bkey_make_mut(trans, &extent_iter, &extent_k,
 				   BTREE_UPDATE_internal_snapshot_node);