When the nr value of a signle entry or their sum overflows, 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 | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/fs/bcachefs/journal_sb.c b/fs/bcachefs/journal_sb.c index db80e506e3ab..230ed99130e4 100644 --- a/fs/bcachefs/journal_sb.c +++ b/fs/bcachefs/journal_sb.c @@ -107,6 +107,7 @@ static int bch2_sb_journal_v2_validate(struct bch_sb *sb, struct bch_sb_field *f unsigned nr; unsigned i; struct u64_range *b; + u64 total_nr = 0, entry_nr; nr = bch2_sb_field_journal_v2_nr_entries(journal); if (!nr) @@ -117,8 +118,21 @@ static int bch2_sb_journal_v2_validate(struct bch_sb *sb, struct bch_sb_field *f return -BCH_ERR_ENOMEM_sb_journal_v2_validate; for (i = 0; i < nr; i++) { + entry_nr = le64_to_cpu(journal->d[i].nr); + if (entry_nr > UINT_MAX) { + prt_printf(err, "Journal v2 entry d[%u] nr %llu overflow\n", + i, entry_nr); + goto err; + } + total_nr += entry_nr; b[i].start = le64_to_cpu(journal->d[i].start); - b[i].end = b[i].start + le64_to_cpu(journal->d[i].nr); + b[i].end = b[i].start + entry_nr; + } + + if (total_nr > UINT_MAX) { + prt_printf(err, "Sum of journal v2 entries nr %llu overflow\n", + total_nr); + goto err; } sort(b, nr, sizeof(*b), u64_range_cmp, NULL); -- 2.43.0