| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.4 88/92] vcs: prevent write access to vcsu devices | Date | Wed, 11 Dec 2019 16:06:19 +0100 |
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From: Nicolas Pitre <nico@fluxnic.net>
commit 0c9acb1af77a3cb8707e43f45b72c95266903cee upstream.
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>
--- drivers/tty/vt/vc_screen.c | 3 +++ 1 file changed, 3 insertions(+)
--- 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 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;
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