Re: [syzbot] Re: [syzbot] [bcachefs?] KASAN: slab-use-after-free Read in bch2_reconstruct_alloc

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Subject: Re: [syzbot] [bcachefs?] KASAN: slab-use-after-free Read in bch2_reconstruct_alloc
Author: lizhi.xu@xxxxxxxxxxxxx

sb is changed?

#syz test: upstream master

diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index 55e1504a8130..b9a3a8e6acd9 100644
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -95,6 +95,7 @@ static void bch2_reconstruct_alloc(struct bch_fs *c)
 	c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
 
 	bch2_write_super(c);
+	ext = bch2_sb_field_get(c->disk_sb.sb, ext);
 	mutex_unlock(&c->sb_lock);
 
 	c->opts.recovery_passes |= bch2_recovery_passes_from_stable(le64_to_cpu(ext->recovery_passes_required[0]));