pty: fix compat ioctls

BugLink: https://bugs.launchpad.net/bugs/1854975
[ Upstream commit 50f45326afab723df529eca54095e2feac24da2d ]

pointer-taking ones need compat_ptr(); int-taking one doesn't.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 9e26c530d2ddb798385a2c731915e3ad336c0cd3..b3208b1b1028d0c0efa287558e7b8814e117d9de 100644 (file)
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -28,6 +28,7 @@
 #include <linux/mount.h>
 #include <linux/file.h>
 #include <linux/ioctl.h>
+#include <linux/compat.h>
 
 #undef TTY_DEBUG_HANGUP
 #ifdef TTY_DEBUG_HANGUP
@@ -488,6 +489,7 @@ static int pty_bsd_ioctl(struct tty_struct *tty,
        return -ENOIOCTLCMD;
 }
 
+#ifdef CONFIG_COMPAT
 static long pty_bsd_compat_ioctl(struct tty_struct *tty,
                                 unsigned int cmd, unsigned long arg)
 {
@@ -495,8 +497,11 @@ static long pty_bsd_compat_ioctl(struct tty_struct *tty,
         * PTY ioctls don't require any special translation between 32-bit and
         * 64-bit userspace, they are already compatible.
         */
-       return pty_bsd_ioctl(tty, cmd, arg);
+       return pty_bsd_ioctl(tty, cmd, (unsigned long)compat_ptr(arg));
 }
+#else
+#define pty_bsd_compat_ioctl NULL
+#endif
 
 static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
 /*
@@ -676,6 +681,7 @@ static int pty_unix98_ioctl(struct tty_struct *tty,
        return -ENOIOCTLCMD;
 }
 
+#ifdef CONFIG_COMPAT
 static long pty_unix98_compat_ioctl(struct tty_struct *tty,
                                 unsigned int cmd, unsigned long arg)
 {
@@ -683,8 +689,12 @@ static long pty_unix98_compat_ioctl(struct tty_struct *tty,
         * PTY ioctls don't require any special translation between 32-bit and
         * 64-bit userspace, they are already compatible.
         */
-       return pty_unix98_ioctl(tty, cmd, arg);
+       return pty_unix98_ioctl(tty, cmd,
+               cmd == TIOCSIG ? arg : (unsigned long)compat_ptr(arg));
 }
+#else
+#define pty_unix98_compat_ioctl NULL
+#endif
 
 /**
  *     ptm_unix98_lookup       -       find a pty master