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authorJiri Slaby <jslaby@suse.cz>2020-07-30 12:55:46 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-07-31 20:22:06 +0200
commitf3af1b68fc96b14b93d1013ce7965723dc53ebbc (patch)
tree99802b547781d2caf80832a8062a36a0420d1ed3 /drivers/tty/vt
parent7df5081cbf5e1c342acd30850a483ef504519937 (diff)
downloadlinux-f3af1b68fc96b14b93d1013ce7965723dc53ebbc.tar.bz2
tty: keyboard, do not speculate on func_table index
It is very unlikely for processor to speculate on the func_table index. The index is uchar and func_table is of size 256. So the compiler would need to screw up and generate a really bad code. But to stay on the safe side, forbid speculation on this user passed index. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Jiri Kosina <jikos@kernel.org> Link: https://lore.kernel.org/r/20200730105546.24268-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/vt')
-rw-r--r--drivers/tty/vt/keyboard.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
index 568b2171f335..a768069b0f9a 100644
--- a/drivers/tty/vt/keyboard.c
+++ b/drivers/tty/vt/keyboard.c
@@ -32,6 +32,7 @@
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/mm.h>
+#include <linux/nospec.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/slab.h>
@@ -2019,7 +2020,7 @@ int vt_do_kdgkb_ioctl(int cmd, struct kbsentry __user *user_kdgkb, int perm)
goto reterr;
}
kbs->kb_string[sizeof(kbs->kb_string)-1] = '\0';
- i = kbs->kb_func;
+ i = array_index_nospec(kbs->kb_func, MAX_NR_FUNC);
switch (cmd) {
case KDGKBSENT: