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authorNicolas Pitre <nico@fluxnic.net>2019-11-05 12:33:16 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-27 09:47:17 +0300
commit0c9acb1af77a3cb8707e43f45b72c95266903cee (patch)
treed96804eb6165e9136204f64a82d8b46a30e2d549 /drivers/tty
parentb2b2dd71e0859436d4e05b2f61f86140250ed3f8 (diff)
downloadlinux-0c9acb1af77a3cb8707e43f45b72c95266903cee.tar.xz
vcs: prevent write access to vcsu devices
Commit d21b0be246bf ("vt: introduce unicode mode for /dev/vcs") guarded against using devices containing attributes as this is not yet implemented. It however failed to guard against writes to any devices as this is also unimplemented. Reported-by: Or Cohen <orcohen@paloaltonetworks.com> Signed-off-by: Nicolas Pitre <npitre@baylibre.com> Cc: <stable@vger.kernel.org> # v4.19+ Cc: Jiri Slaby <jslaby@suse.com> Fixes: d21b0be246bf ("vt: introduce unicode mode for /dev/vcs") Link: https://lore.kernel.org/r/nycvar.YSQ.7.76.1911051030580.30289@knanqh.ubzr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/vt/vc_screen.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c
index 1f042346e722..778f83ea2249 100644
--- a/drivers/tty/vt/vc_screen.c
+++ b/drivers/tty/vt/vc_screen.c
@@ -456,6 +456,9 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
size_t ret;
char *con_buf;
+ if (use_unicode(inode))
+ return -EOPNOTSUPP;
+
con_buf = (char *) __get_free_page(GFP_KERNEL);
if (!con_buf)
return -ENOMEM;