When journal v2 entry nr overflow, it will cause the value of ja->nr to be incorrect, this will result in the allocated memory to ja->buckets being too small, leading to out of bounds access in bch2_dev_journal_init.
Reported-by: syzbot+47ecc948aadfb2ab3...@syzkaller.appspotmail.com Signed-off-by: Lizhi Xu <lizhi...@windriver.com> --- fs/bcachefs/journal_sb.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/bcachefs/journal_sb.c b/fs/bcachefs/journal_sb.c index db80e506e3ab..db2b2100e4e5 100644 --- a/fs/bcachefs/journal_sb.c +++ b/fs/bcachefs/journal_sb.c @@ -119,6 +119,11 @@ static int bch2_sb_journal_v2_validate(struct bch_sb *sb, struct bch_sb_field *f for (i = 0; i < nr; i++) { b[i].start = le64_to_cpu(journal->d[i].start); b[i].end = b[i].start + le64_to_cpu(journal->d[i].nr); + if (le64_to_cpu(journal->d[i].nr) > UINT_MAX) { + prt_printf(err, "journal v2 entry d[%u].nr %llu overflow\n", + i, le64_to_cpu(journal->d[i].nr)); + goto err; + } } sort(b, nr, sizeof(*b), u64_range_cmp, NULL); -- 2.43.0