bcachefs: Fix NULL ptr dereference in btree_node_iter_and_journal_peek

Add NULL check for key returned from bch2_btree_and_journal_iter_peek in
btree_node_iter_and_journal_peek to avoid NULL ptr dereference in
bch2_bkey_buf_reassemble.

When key returned from bch2_btree_and_journal_iter_peek is NULL it means
that btree topology needs repair. Print topology error message with
position at which node wasn't found, its parent node information and
btree_id with level.

Return error code returned by bch2_topology_error to ensure that topology
error is handled properly by recovery.

Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=005ef9aa519f30d97657
Fixes: 5222a4607cd8 ("bcachefs: BTREE_ITER_WITH_JOURNAL")
Suggested-by: Alan Huang <[email protected]>
Suggested-by: Kent Overstreet <[email protected]>
Signed-off-by: Piotr Zalewski <[email protected]>
Signed-off-by: Kent Overstreet <[email protected]>

0 files changed, 0 insertions, 0 deletions