Commit 472237b6 authored by Pei Li's avatar Pei Li Committed by Kent Overstreet
Browse files

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: default avatar <syzbot+835d255ad6bc7f29ee12@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=835d255ad6bc7f29ee12


Signed-off-by: default avatarPei Li <peili.dev@gmail.com>
Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 211c581d

fs/bcachefs/journal_seq_blacklist.c

+1 −1
Original line number Diff line number Diff line
@@ -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));