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From: Camila Alvarez <cam.alvarez.i@gmail.com>
To: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Brian Foster <bfoster@redhat.com>,
	linux-bcachefs@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Camila Alvarez <cam.alvarez.i@gmail.com>,
	syzbot+249018ea545364f78d04@syzkaller.appspotmail.com
Subject: [PATCH] guard against unknown r->data_type in bch2_sb_dev_has_data()
Date: Tue, 14 May 2024 21:47:22 -0400
Message-Id: <20240515014720.2482142-1-cam.alvarez.i@gmail.com>
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Shift is perfomed only when the data type makes sense.

Fix a missing guard on r->data_type being known.

Reported-by: syzbot+249018ea545364f78d04@syzkaller.appspotmail.com
Signed-off-by: Camila Alvarez <cam.alvarez.i@gmail.com>
---
 fs/bcachefs/replicas.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/bcachefs/replicas.c b/fs/bcachefs/replicas.c
index 678b9c20e251..0fa91d0bf951 100644
--- a/fs/bcachefs/replicas.c
+++ b/fs/bcachefs/replicas.c
@@ -1006,14 +1006,14 @@ unsigned bch2_sb_dev_has_data(struct bch_sb *sb, unsigned dev)
 
 		for_each_replicas_entry(replicas, r)
 			for (i = 0; i < r->nr_devs; i++)
-				if (r->devs[i] == dev)
+				if (r->devs[i] == dev && r->data_type < BCH_DATA_NR)
 					data_has |= 1 << r->data_type;
 	} else if (replicas_v0) {
 		struct bch_replicas_entry_v0 *r;
 
 		for_each_replicas_entry_v0(replicas_v0, r)
 			for (i = 0; i < r->nr_devs; i++)
-				if (r->devs[i] == dev)
+				if (r->devs[i] == dev && r->data_type < BCH_DATA_NR)
 					data_has |= 1 << r->data_type;
 	}
 
-- 
2.34.1