This is a note to let you know that I've just added the patch titled
USB: serial: whiteheat: fix heap overflow in WHITEHEAT_GET_DTR_RTS
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-serial-whiteheat-fix-heap-overflow-in-whiteheat_get_dtr_rts.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e23e50e7acc8d8f16498e9c129db33e6a00e80eb Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Wed, 20 Apr 2022 17:12:34 -0700
Subject: USB: serial: whiteheat: fix heap overflow in WHITEHEAT_GET_DTR_RTS
From: Kees Cook <keescook@xxxxxxxxxxxx>
commit e23e50e7acc8d8f16498e9c129db33e6a00e80eb upstream.
The sizeof(struct whitehat_dr_info) can be 4 bytes under CONFIG_AEABI=n
due to "-mabi=apcs-gnu", even though it has a single u8:
whiteheat_private {
__u8 mcr; /* 0 1 */
/* size: 4, cachelines: 1, members: 1 */
/* padding: 3 */
/* last cacheline: 4 bytes */
};
The result is technically harmless, as both the source and the
destinations are currently the same allocation size (4 bytes) and don't
use their padding, but if anything were to ever be added after the
"mcr" member in "struct whiteheat_private", it would be overwritten. The
structs both have a single u8 "mcr" member, but are 4 bytes in padded
size. The memcpy() destination was explicitly targeting the u8 member
(size 1) with the length of the whole structure (size 4), triggering
the memcpy buffer overflow warning:
In file included from include/linux/string.h:253,
from include/linux/bitmap.h:11,
from include/linux/cpumask.h:12,
from include/linux/smp.h:13,
from include/linux/lockdep.h:14,
from include/linux/spinlock.h:62,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:6,
from include/linux/slab.h:15,
from drivers/usb/serial/whiteheat.c:17:
In function 'fortify_memcpy_chk',
inlined from 'firm_send_command' at drivers/usb/serial/whiteheat.c:587:4:
include/linux/fortify-string.h:328:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
328 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Instead, just assign the one byte directly.
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Link: https://lore.kernel.org/lkml/202204142318.vDqjjSFn-lkp@xxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220421001234.2421107-1-keescook@xxxxxxxxxxxx
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/serial/whiteheat.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -644,9 +644,8 @@ static int firm_send_command(struct usb_
switch (command) {
case WHITEHEAT_GET_DTR_RTS:
info = usb_get_serial_port_data(port);
- memcpy(&info->mcr, command_info->result_buffer,
- sizeof(struct whiteheat_dr_info));
- break;
+ info->mcr = command_info->result_buffer[0];
+ break;
}
}
exit:
Patches currently in stable-queue which might be from keescook@xxxxxxxxxxxx are
queue-4.9/usb-serial-whiteheat-fix-heap-overflow-in-whiteheat_get_dtr_rts.patch
