linux-kernel - [PATCH 4.19 07/39] dm bufio: subtract the number of initial sectors in dm_bufio_get_device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210310132319.964034941@linuxfoundation.org>
Date:   Wed, 10 Mar 2021 14:24:15 +0100
From:   gregkh@...uxfoundation.org
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Mikulas Patocka <mpatocka@...hat.com>,
        Milan Broz <gmazyland@...il.com>,
        Mike Snitzer <snitzer@...hat.com>
Subject: [PATCH 4.19 07/39] dm bufio: subtract the number of initial sectors in dm_bufio_get_device_size

From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

From: Mikulas Patocka <mpatocka@...hat.com>

commit a14e5ec66a7a66e57b24e2469f9212a78460207e upstream.

dm_bufio_get_device_size returns the device size in blocks. Before
returning the value, we must subtract the nubmer of starting
sectors. The number of starting sectors may not be divisible by block
size.

Note that currently, no target is using dm_bufio_set_sector_offset and
dm_bufio_get_device_size simultaneously, so this change has no effect.
However, an upcoming dm-verity-fec fix needs this change.

Signed-off-by: Mikulas Patocka <mpatocka@...hat.com>
Reviewed-by: Milan Broz <gmazyland@...il.com>
Cc: stable@...r.kernel.org
Signed-off-by: Mike Snitzer <snitzer@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/md/dm-bufio.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1463,6 +1463,10 @@ EXPORT_SYMBOL_GPL(dm_bufio_get_block_siz
 sector_t dm_bufio_get_device_size(struct dm_bufio_client *c)
 {
 	sector_t s = i_size_read(c->bdev->bd_inode) >> SECTOR_SHIFT;
+	if (s >= c->start)
+		s -= c->start;
+	else
+		s = 0;
 	if (likely(c->sectors_per_block_bits >= 0))
 		s >>= c->sectors_per_block_bits;
 	else