diff options
| author | Heinz Mauelshagen <heinzm@redhat.com> | 2014-10-17 13:38:50 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-21 09:22:53 -0800 |
| commit | 513f8da83b3ef6cf1475da6ef3d851286e8466fa (patch) | |
| tree | c3f9420ac5cab491dd9edc13b8a3529b5e27c1de /drivers/md | |
| parent | fe30b804a20bbc3218193f0d528e9749332fb06a (diff) | |
dm raid: ensure superblock's size matches device's logical block size
commit 40d43c4b4cac4c2647bf07110d7b07d35f399a84 upstream.
The dm-raid superblock (struct dm_raid_superblock) is padded to 512
bytes and that size is being used to read it in from the metadata
device into one preallocated page.
Reading or writing this on a 512-byte sector device works fine but on
a 4096-byte sector device this fails.
Set the dm-raid superblock's size to the logical block size of the
metadata device, because IO at that size is guaranteed too work. Also
add a size check to avoid silent partial metadata loss in case the
superblock should ever grow past the logical block size or PAGE_SIZE.
[includes pointer math fix from Dan Carpenter]
Reported-by: "Liuhua Wang" <lwang@suse.com>
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-raid.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 2dea49c4279e..84cddccc0249 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -785,8 +785,7 @@ struct dm_raid_superblock { __le32 layout; __le32 stripe_sectors; - __u8 pad[452]; /* Round struct to 512 bytes. */ - /* Always set to 0 when writing. */ + /* Remainder of a logical block is zero-filled when writing (see super_sync()). */ } __packed; static int read_disk_sb(struct md_rdev *rdev, int size) @@ -823,7 +822,7 @@ static void super_sync(struct mddev *mddev, struct md_rdev *rdev) test_bit(Faulty, &(rs->dev[i].rdev.flags))) failed_devices |= (1ULL << i); - memset(sb, 0, sizeof(*sb)); + memset(sb + 1, 0, rdev->sb_size - sizeof(*sb)); sb->magic = cpu_to_le32(DM_RAID_MAGIC); sb->features = cpu_to_le32(0); /* No features yet */ @@ -858,7 +857,11 @@ static int super_load(struct md_rdev *rdev, struct md_rdev *refdev) uint64_t events_sb, events_refsb; rdev->sb_start = 0; - rdev->sb_size = sizeof(*sb); + rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev); + if (rdev->sb_size < sizeof(*sb) || rdev->sb_size > PAGE_SIZE) { + DMERR("superblock size of a logical block is no longer valid"); + return -EINVAL; + } ret = read_disk_sb(rdev, rdev->sb_size); if (ret) |