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 <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2024-10-25 13:13:05 -04:00
parent a25a83de45
commit 8e910ca20e

View File

@ -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);