From 472237b69d071c877e97bf0bc3eab1be865fad29 Mon Sep 17 00:00:00 2001
From: Pei Li <peili.dev@gmail.com>
Date: Tue, 25 Jun 2024 11:41:29 -0700
Subject: [PATCH] bcachefs: Fix shift-out-of-bounds in
bch2_blacklist_entries_gc
This series fix the shift-out-of-bounds issue in
bch2_blacklist_entries_gc().
Instead of passing 0 to eytzinger0_first() when iterating the entries,
we explicitly check 0 and initialize i to be 0.
syzbot has tested the proposed patch and the reproducer did not trigger
any issue:
Reported-and-tested-by: syzbot+835d255ad6bc7f29ee12@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=835d255ad6bc7f29ee12
Signed-off-by: Pei Li <peili.dev@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
fs/bcachefs/journal_seq_blacklist.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/bcachefs/journal_seq_blacklist.c b/fs/bcachefs/journal_seq_blacklist.c
index ed48467096115..1f25c111c54cd 100644
--- a/fs/bcachefs/journal_seq_blacklist.c
+++ b/fs/bcachefs/journal_seq_blacklist.c
@@ -232,7 +232,7 @@ bool bch2_blacklist_entries_gc(struct bch_fs *c)
BUG_ON(nr != t->nr);
unsigned i;
- for (src = bl->start, i = eytzinger0_first(t->nr);
+ for (src = bl->start, i = t->nr == 0 ? 0 : eytzinger0_first(t->nr);
src < bl->start + nr;
src++, i = eytzinger0_next(i, nr)) {
BUG_ON(t->entries[i].start != le64_to_cpu(src->start));
--
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