From 8e910ca20e112d7f06ba3bf631a06ddb5ce14657 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Fri, 25 Oct 2024 13:13:05 -0400 Subject: [PATCH] bcachefs: Fix UAF in bch2_reconstruct_alloc() write_super() -> sb_counters_from_cpu() may reallocate the superblock Reported-by: syzbot+9fc4dac4775d07bcfe34@syzkaller.appspotmail.com Signed-off-by: Kent Overstreet --- fs/bcachefs/recovery.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c index 454b5a32dd7f..0ebc76dd7eb5 100644 --- a/fs/bcachefs/recovery.c +++ b/fs/bcachefs/recovery.c @@ -94,11 +94,10 @@ static void bch2_reconstruct_alloc(struct bch_fs *c) __set_bit_le64(BCH_FSCK_ERR_accounting_mismatch, ext->errors_silent); c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info); - bch2_write_super(c); - mutex_unlock(&c->sb_lock); - c->opts.recovery_passes |= bch2_recovery_passes_from_stable(le64_to_cpu(ext->recovery_passes_required[0])); + bch2_write_super(c); + mutex_unlock(&c->sb_lock); bch2_shoot_down_journal_keys(c, BTREE_ID_alloc, 0, BTREE_MAX_DEPTH, POS_MIN, SPOS_MAX);