| Message ID | alpine.LRH.2.02.2001150833180.31494@file01.intranet.prod.int.rdu2.redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: fix an integer overflow in logical block size | expand |
Mikulas, > This patch changes the logical block size from unsigned short to > unsigned int to avoid the overflow. Looks fine. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
On Wed, Jan 15, 2020 at 08:35:25AM -0500, Mikulas Patocka wrote: > Logical block size has type unsigned short. That means that it can be at > most 32768. However, there are architectures that can run with 64k pages > (for example arm64) and on these architectures, it may be possible to > create block devices with 64k block size. The patch looks fine, and other drivers(loop, nbd, virtio_blk, ...) allow user to pass customized logical block size, and the passed size can be > 32k. Reviewed-by: Ming Lei <ming.lei@redhat.com> Thanks, Ming
On 1/15/20 6:35 AM, Mikulas Patocka wrote: > Logical block size has type unsigned short. That means that it can be at > most 32768. However, there are architectures that can run with 64k pages > (for example arm64) and on these architectures, it may be possible to > create block devices with 64k block size. > > For exmaple (run this on an architecture with 64k pages): > # modprobe brd rd_size=1048576 > # dmsetup create cache --table "0 `blockdev --getsize /dev/ram0` writecache s /dev/ram0 /dev/ram1 65536 0" > # mkfs.ext4 -b 65536 /dev/mapper/cache > # mount -t ext4 /dev/mapper/cache /mnt/test > > Mount will fail with this error because it tries to read the superblock using 2-sector > access: > device-mapper: writecache: I/O is not aligned, sector 2, size 1024, block size 65536 > EXT4-fs (dm-0): unable to read superblock > > This patch changes the logical block size from unsigned short to unsigned > int to avoid the overflow. Thanks, applied.
On Wed, Jan 15, 2020 at 08:35:25AM -0500, Mikulas Patocka wrote: > Logical block size has type unsigned short. That means that it can be at > most 32768. However, there are architectures that can run with 64k pages > (for example arm64) and on these architectures, it may be possible to > create block devices with 64k block size. > > For exmaple (run this on an architecture with 64k pages): > # modprobe brd rd_size=1048576 > # dmsetup create cache --table "0 `blockdev --getsize /dev/ram0` writecache s /dev/ram0 /dev/ram1 65536 0" > # mkfs.ext4 -b 65536 /dev/mapper/cache > # mount -t ext4 /dev/mapper/cache /mnt/test > > Mount will fail with this error because it tries to read the superblock using 2-sector > access: > device-mapper: writecache: I/O is not aligned, sector 2, size 1024, block size 65536 > EXT4-fs (dm-0): unable to read superblock > > This patch changes the logical block size from unsigned short to unsigned > int to avoid the overflow. > > Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Mikulas, a question about this patch. In crypt_io_hints() in drivers/md/dm-crypt.c there is: limits->logical_block_size = max_t(unsigned short, limits->logical_block_size, cc->sector_size); Shouldn't that have been changed to 'unsigned int', now that limits->logical_block_size is 'unsigned int' rather than 'unsigned short'? - Eric
Index: linux-2.6/block/blk-settings.c =================================================================== --- linux-2.6.orig/block/blk-settings.c 2020-01-15 14:02:54.000000000 +0100 +++ linux-2.6/block/blk-settings.c 2020-01-15 14:02:54.000000000 +0100 @@ -328,7 +328,7 @@ EXPORT_SYMBOL(blk_queue_max_segment_size * storage device can address. The default of 512 covers most * hardware. **/ -void blk_queue_logical_block_size(struct request_queue *q, unsigned short size) +void blk_queue_logical_block_size(struct request_queue *q, unsigned int size) { q->limits.logical_block_size = size; Index: linux-2.6/include/linux/blkdev.h =================================================================== --- linux-2.6.orig/include/linux/blkdev.h 2020-01-15 14:02:54.000000000 +0100 +++ linux-2.6/include/linux/blkdev.h 2020-01-15 14:11:07.000000000 +0100 @@ -328,6 +328,7 @@ struct queue_limits { unsigned int max_sectors; unsigned int max_segment_size; unsigned int physical_block_size; + unsigned int logical_block_size; unsigned int alignment_offset; unsigned int io_min; unsigned int io_opt; @@ -338,7 +339,6 @@ struct queue_limits { unsigned int discard_granularity; unsigned int discard_alignment; - unsigned short logical_block_size; unsigned short max_segments; unsigned short max_integrity_segments; unsigned short max_discard_segments; @@ -1077,7 +1077,7 @@ extern void blk_queue_max_write_same_sec unsigned int max_write_same_sectors); extern void blk_queue_max_write_zeroes_sectors(struct request_queue *q, unsigned int max_write_same_sectors); -extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); +extern void blk_queue_logical_block_size(struct request_queue *, unsigned int); extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); extern void blk_queue_alignment_offset(struct request_queue *q, unsigned int alignment); @@ -1291,7 +1291,7 @@ static inline unsigned int queue_max_seg return q->limits.max_segment_size; } -static inline unsigned short queue_logical_block_size(const struct request_queue *q) +static inline unsigned queue_logical_block_size(const struct request_queue *q) { int retval = 512; @@ -1301,7 +1301,7 @@ static inline unsigned short queue_logic return retval; } -static inline unsigned short bdev_logical_block_size(struct block_device *bdev) +static inline unsigned int bdev_logical_block_size(struct block_device *bdev) { return queue_logical_block_size(bdev_get_queue(bdev)); } Index: linux-2.6/drivers/md/dm-snap-persistent.c =================================================================== --- linux-2.6.orig/drivers/md/dm-snap-persistent.c 2019-10-10 16:52:03.000000000 +0200 +++ linux-2.6/drivers/md/dm-snap-persistent.c 2020-01-15 14:14:11.000000000 +0100 @@ -17,7 +17,7 @@ #include <linux/dm-bufio.h> #define DM_MSG_PREFIX "persistent snapshot" -#define DM_CHUNK_SIZE_DEFAULT_SECTORS 32 /* 16KB */ +#define DM_CHUNK_SIZE_DEFAULT_SECTORS 32U /* 16KB */ #define DM_PREFETCH_CHUNKS 12 Index: linux-2.6/drivers/md/raid0.c =================================================================== --- linux-2.6.orig/drivers/md/raid0.c 2019-12-11 09:31:25.000000000 +0100 +++ linux-2.6/drivers/md/raid0.c 2020-01-15 14:15:14.000000000 +0100 @@ -87,7 +87,7 @@ static int create_strip_zones(struct mdd char b[BDEVNAME_SIZE]; char b2[BDEVNAME_SIZE]; struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); - unsigned short blksize = 512; + unsigned blksize = 512; *private_conf = ERR_PTR(-ENOMEM); if (!conf)
Logical block size has type unsigned short. That means that it can be at most 32768. However, there are architectures that can run with 64k pages (for example arm64) and on these architectures, it may be possible to create block devices with 64k block size. For exmaple (run this on an architecture with 64k pages): # modprobe brd rd_size=1048576 # dmsetup create cache --table "0 `blockdev --getsize /dev/ram0` writecache s /dev/ram0 /dev/ram1 65536 0" # mkfs.ext4 -b 65536 /dev/mapper/cache # mount -t ext4 /dev/mapper/cache /mnt/test Mount will fail with this error because it tries to read the superblock using 2-sector access: device-mapper: writecache: I/O is not aligned, sector 2, size 1024, block size 65536 EXT4-fs (dm-0): unable to read superblock This patch changes the logical block size from unsigned short to unsigned int to avoid the overflow. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org --- block/blk-settings.c | 2 +- drivers/md/dm-snap-persistent.c | 2 +- drivers/md/raid0.c | 2 +- include/linux/blkdev.h | 8 ++++---- 4 files changed, 7 insertions(+), 7 deletions(-)