On Wed, Dec 18, 2019 at 7:45 PM Ben Hutchings email@example.com wrote:
On Tue, 2019-12-17 at 23:16 +0100, Arnd Bergmann wrote:
Rather than relying on fs/compat_ioctl.c, this adds support for a compat_ioctl() callback in the ide-floppy driver directly, which lets it translate the scsi commands.
After this, and before "compat_ioctl: move HDIO ioctl handling into drivers/ide", compat ioctls on an IDE hard drive will result in a null pointer dereference in ide_gd_compat_ioctl(). Not sure how much that really matters though.
I'm sure it makes no difference in the end, but you are of course right that this is a bug. I've folded in a check now, and leaving that in place even after it is no longer needed:
--- a/drivers/ide/ide-gd.c +++ b/drivers/ide/ide-gd.c @@ -348,6 +348,9 @@ static int ide_gd_compat_ioctl(struct block_device *bdev, fmode_t mode, struct ide_disk_obj *idkp = ide_drv_g(bdev->bd_disk, ide_disk_obj); ide_drive_t *drive = idkp->drive;
+ if (!drive->disk_ops->compat_ioctl) + return -ENOIOCTLCMD; + return drive->disk_ops->compat_ioctl(drive, bdev, mode, cmd, arg); } #endif
I pushed out an updated signed tag with this change.
Thanks for the continued careful review!