[PATCH 38/38] vt_ioctl: move perm checks level up

From: Jiri Slaby
Date: Mon Jun 15 2020 - 03:49:38 EST


Synchronize with others and check perm directly in vt_k_ioctl.
We do not need to pass perm to do_fontx_ioctl and do_unimap_ioctl then.

Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/tty/vt/vt_ioctl.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
index 224f2a564e13..91c301775047 100644
--- a/drivers/tty/vt/vt_ioctl.c
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -486,7 +486,7 @@ static int vt_k_ioctl(struct tty_struct *tty, unsigned int cmd,
}

static inline int do_fontx_ioctl(int cmd,
- struct consolefontdesc __user *user_cfd, int perm,
+ struct consolefontdesc __user *user_cfd,
struct console_font_op *op)
{
struct consolefontdesc cfdarg;
@@ -497,8 +497,6 @@ static inline int do_fontx_ioctl(int cmd,

switch (cmd) {
case PIO_FONTX:
- if (!perm)
- return -EPERM;
op->op = KD_FONT_OP_SET;
op->flags = KD_FONT_FLAG_OLD;
op->width = 8;
@@ -552,7 +550,7 @@ static int vt_io_fontreset(struct console_font_op *op)
}

static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud,
- int perm, struct vc_data *vc)
+ struct vc_data *vc)
{
struct unimapdesc tmp;

@@ -560,11 +558,9 @@ static inline int do_unimap_ioctl(int cmd, struct unimapdesc __user *user_ud,
return -EFAULT;
switch (cmd) {
case PIO_UNIMAP:
- if (!perm)
- return -EPERM;
return con_set_unimap(vc, tmp.entry_ct, tmp.entries);
case GIO_UNIMAP:
- if (!perm && fg_console != vc->vc_num)
+ if (fg_console != vc->vc_num)
return -EPERM;
return con_get_unimap(vc, tmp.entry_ct, &(user_ud->entry_ct),
tmp.entries);
@@ -607,8 +603,12 @@ static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up,
return con_get_cmap(up);

case PIO_FONTX:
+ if (!perm)
+ return -EPERM;
+
+ fallthrough;
case GIO_FONTX:
- return do_fontx_ioctl(cmd, up, perm, &op);
+ return do_fontx_ioctl(cmd, up, &op);

case PIO_FONTRESET:
if (!perm)
@@ -640,7 +640,10 @@ static int vt_io_ioctl(struct vc_data *vc, unsigned int cmd, void __user *up,

case PIO_UNIMAP:
case GIO_UNIMAP:
- return do_unimap_ioctl(cmd, up, perm, vc);
+ if (!perm)
+ return -EPERM;
+
+ return do_unimap_ioctl(cmd, up, vc);

default:
return -ENOIOCTLCMD;
--
2.27.0