Re: [PATCH 4.19 030/306] synclink_gt(): fix compat_ioctl()

From: Pavel Machek
Date: Sat Nov 30 2019 - 05:28:15 EST


Hi!

> From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
>
> [ Upstream commit 27230e51349fde075598c1b59d15e1ff802f3f6e ]
>
> compat_ptr() for pointer-taking ones...
>
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

> +++ b/drivers/tty/synclink_gt.c
> @@ -1186,14 +1186,13 @@ static long slgt_compat_ioctl(struct tty_struct *tty,
> unsigned int cmd, unsigned long arg)
> {
> struct slgt_info *info = tty->driver_data;
> - int rc = -ENOIOCTLCMD;
> + int rc;
>
> if (sanity_check(info, tty->name, "compat_ioctl"))
> return -ENODEV;
> DBGINFO(("%s compat_ioctl() cmd=%08X\n", info->device_name, cmd));
>
> switch (cmd) {
> -
> case MGSL_IOCSPARAMS32:
> rc = set_params32(info, compat_ptr(arg));
> break;
> @@ -1213,18 +1212,11 @@ static long slgt_compat_ioctl(struct tty_struct *tty,
> case MGSL_IOCWAITGPIO:
> case MGSL_IOCGXSYNC:
> case MGSL_IOCGXCTRL:
> - case MGSL_IOCSTXIDLE:
> - case MGSL_IOCTXENABLE:
> - case MGSL_IOCRXENABLE:
> - case MGSL_IOCTXABORT:
> - case TIOCMIWAIT:
> - case MGSL_IOCSIF:
> - case MGSL_IOCSXSYNC:
> - case MGSL_IOCSXCTRL:
> - rc = ioctl(tty, cmd, arg);
> + rc = ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
> break;
> + default:
> + rc = ioctl(tty, cmd, arg);
> }

Ok, so this used to only pass select calls to ioctl() and now it
passes everything thanks to default: marking. I guess that's suitable
for mainline, but is it also suitable for -stable?

Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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