From: Milan Broz Make size of dm_ioctl struct always 312 bytes on all supported architectures. This change retains compatibility with already-compiled code because it uses an embedded offset to locate the payload that follows the structure. On 64-bit architectures there is no change at all; on 32-bit we are increasing the size of dm-ioctl from 308 to 312 bytes. Currently with 32-bit userspace / 64-bit kernel on x86_64 some ioctls (including rename, message) are incorrectly rejected by the comparison against 'param + 1'. This breaks userspace lvrename and multipath 'fail_if_no_path' changes, for example. (BTW Device-mapper uses its own versioning and ignores the ioctl size bits. Only the generic ioctl compat code on mixed arches checks them, and that will continue to accept both sizes for now, but we intend to list 308 as deprecated and eventually remove it.) Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon Cc: Guido Guenther Cc: Kevin Corry Cc: stable@kernel.org --- drivers/md/dm-ioctl.c | 6 +++--- include/linux/dm-ioctl.h | 5 +++-- 2 files changed, 6 insertions(+), 5 deletions(-) Index: linux-2.6.23/drivers/md/dm-ioctl.c =================================================================== --- linux-2.6.23.orig/drivers/md/dm-ioctl.c 2007-10-12 13:15:21.000000000 +0100 +++ linux-2.6.23/drivers/md/dm-ioctl.c 2007-10-12 13:15:29.000000000 +0100 @@ -700,7 +700,7 @@ static int dev_rename(struct dm_ioctl *p int r; char *new_name = (char *) param + param->data_start; - if (new_name < (char *) (param + 1) || + if (new_name < (char *) param->data || invalid_str(new_name, (void *) param + param_size)) { DMWARN("Invalid new logical volume name supplied."); return -EINVAL; @@ -726,7 +726,7 @@ static int dev_set_geometry(struct dm_io if (!md) return -ENXIO; - if (geostr < (char *) (param + 1) || + if (geostr < (char *) param->data || invalid_str(geostr, (void *) param + param_size)) { DMWARN("Invalid geometry supplied."); goto out; @@ -1233,7 +1233,7 @@ static int target_message(struct dm_ioct if (r) goto out; - if (tmsg < (struct dm_target_msg *) (param + 1) || + if (tmsg < (struct dm_target_msg *) param->data || invalid_str(tmsg->message, (void *) param + param_size)) { DMWARN("Invalid target message parameters."); r = -EINVAL; Index: linux-2.6.23/include/linux/dm-ioctl.h =================================================================== --- linux-2.6.23.orig/include/linux/dm-ioctl.h 2007-10-12 13:15:21.000000000 +0100 +++ linux-2.6.23/include/linux/dm-ioctl.h 2007-10-12 13:15:29.000000000 +0100 @@ -131,6 +131,7 @@ struct dm_ioctl { char name[DM_NAME_LEN]; /* device name */ char uuid[DM_UUID_LEN]; /* unique identifier for * the block device */ + char data[7]; /* padding or data */ }; /* @@ -285,9 +286,9 @@ typedef char ioctl_struct[308]; #define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl) #define DM_VERSION_MAJOR 4 -#define DM_VERSION_MINOR 11 +#define DM_VERSION_MINOR 12 #define DM_VERSION_PATCHLEVEL 0 -#define DM_VERSION_EXTRA "-ioctl (2006-10-12)" +#define DM_VERSION_EXTRA "-ioctl (2007-10-02)" /* Status bits */ #define DM_READONLY_FLAG (1 << 0) /* In/Out */