Re: [syzbot] Re: [syzbot] [bcachefs?] KASAN: slab-out-of-bounds Write in bch2_dev_journal_init

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@xxxxxxxxxxxxxxx.

***

Subject: Re: [syzbot] [bcachefs?] KASAN: slab-out-of-bounds Write in bch2_dev_journal_init
Author: lizhi.xu@xxxxxxxxxxxxx

two obj are null ?

#syz test: upstream c3f2d783a459

diff --git a/fs/bcachefs/journal.c b/fs/bcachefs/journal.c
index 13669dd0e375..1219f921690a 100644
--- a/fs/bcachefs/journal.c
+++ b/fs/bcachefs/journal.c
@@ -1304,6 +1304,10 @@ int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
 
 	ja->nr = 0;
 
+	struct printbuf buf = PRINTBUF;
+	prt_printf(&buf, "ja nr: %u, %s\n", ja->nr, journal_buckets_v2, journal_buckets, __func__);
+	printbuf_exit(&buf);
+
 	if (journal_buckets_v2) {
 		unsigned nr = bch2_sb_field_journal_v2_nr_entries(journal_buckets_v2);
 
@@ -1311,7 +1315,8 @@ int bch2_dev_journal_init(struct bch_dev *ca, struct bch_sb *sb)
 			ja->nr += le64_to_cpu(journal_buckets_v2->d[i].nr);
 	} else if (journal_buckets) {
 		ja->nr = bch2_nr_journal_buckets(journal_buckets);
-	}
+	} else
+		return -EINVAL;
 
 	ja->bucket_seq = kcalloc(ja->nr, sizeof(u64), GFP_KERNEL);
 	if (!ja->bucket_seq)