patch "vt_ioctl: add array_index_nospec to VT_ACTIVATE" added to tty-linus

This is a note to let you know that I've just added the patch titled

vt_ioctl: add array_index_nospec to VT_ACTIVATE

to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 28cb138f559f8c1a1395f5564f86b8bbee83631b Mon Sep 17 00:00:00 2001
From: Jakob Koschel <[email protected]>
Date: Thu, 27 Jan 2022 15:44:05 +0100
Subject: vt_ioctl: add array_index_nospec to VT_ACTIVATE

in vt_setactivate an almost identical code path has been patched with array_index_nospec. In the VT_ACTIVATE path the user input is from a system call argument instead of a usercopy. For consistency both code paths should have the same mitigations applied.

Kasper Acknowledgements: Jakob Koschel, Brian Johannesmeyer, Kaveh Razavi, Herbert Bos, Cristiano Giuffrida from the VUSec group at VU Amsterdam.

---
 drivers/tty/vt/vt_ioctl.c | 1 +
 1 file changed, 1 insertion(+)

index e0714a9c9fd7..58013698635f 100644
@@ -845,6 +845,7 @@ int vt_ioctl(struct tty_struct *tty,
 			return -ENXIO;
 
 		arg--;
+		arg = array_index_nospec(arg, MAX_NR_CONSOLES);
 		console_lock();
 		ret = vc_allocate(arg);
 		console_unlock();

2.35.1