This is a note to let you know that I've just added the patch titled
tty: fix compat TIOCGSERIAL leaking uninitialized memory
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 17329563a97df3ba474eca5037c1336e46e14ff8 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Mon, 24 Feb 2020 10:20:43 -0800
Subject: tty: fix compat TIOCGSERIAL leaking uninitialized memory
Commit 77654350306a ("take compat TIOC[SG]SERIAL treatment into
tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start
copying a whole 'serial_struct32' to userspace rather than individual
fields, but failed to initialize all padding and fields -- namely the
hole after the 'iomem_reg_shift' field, and the 'reserved' field.
Fix this by initializing the struct to zero.
[v2: use sizeof, and convert the adjacent line for consistency.]
Reported-by: syzbot+8da9175e28eadcb203ce@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 77654350306a ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()")
Cc: <stable@xxxxxxxxxxxxxxx> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Acked-by: Jiri Slaby <jslaby@xxxxxxx>
Link: https://lore.kernel.org/r/20200224182044.234553-2-ebiggers@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/tty_io.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 1fcf7ad83dfa..db4a13bc855e 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2730,7 +2730,9 @@ static int compat_tty_tiocgserial(struct tty_struct *tty,
struct serial_struct32 v32;
struct serial_struct v;
int err;
- memset(&v, 0, sizeof(struct serial_struct));
+
+ memset(&v, 0, sizeof(v));
+ memset(&v32, 0, sizeof(v32));
if (!tty->ops->set_serial)
return -ENOTTY;
--
2.25.1
