This is a note to let you know that I've just added the patch titled
comedi: vmk80xx: fix transfer-buffer overflows
to the 4.4-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:
comedi-vmk80xx-fix-transfer-buffer-overflows.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a23461c47482fc232ffc9b819539d1f837adf2b1 Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@xxxxxxxxxx>
Date: Mon, 25 Oct 2021 13:45:30 +0200
Subject: comedi: vmk80xx: fix transfer-buffer overflows
From: Johan Hovold <johan@xxxxxxxxxx>
commit a23461c47482fc232ffc9b819539d1f837adf2b1 upstream.
The driver uses endpoint-sized USB transfer buffers but up until
recently had no sanity checks on the sizes.
Commit e1f13c879a7c ("staging: comedi: check validity of wMaxPacketSize
of usb endpoints found") inadvertently fixed NULL-pointer dereferences
when accessing the transfer buffers in case a malicious device has a
zero wMaxPacketSize.
Make sure to allocate buffers large enough to handle also the other
accesses that are done without a size check (e.g. byte 18 in
vmk80xx_cnt_insn_read() for the VMK8061_MODEL) to avoid writing beyond
the buffers, for example, when doing descriptor fuzzing.
The original driver was for a low-speed device with 8-byte buffers.
Support was later added for a device that uses bulk transfers and is
presumably a full-speed device with a maximum 64-byte wMaxPacketSize.
Fixes: 985cafccbf9b ("Staging: Comedi: vmk80xx: Add k8061 support")
Cc: stable@xxxxxxxxxxxxxxx # 2.6.31
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Reviewed-by: Ian Abbott <abbotti@xxxxxxxxx>
Link: https://lore.kernel.org/r/20211025114532.4599-4-johan@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/vmk80xx.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/staging/comedi/drivers/vmk80xx.c
+++ b/drivers/staging/comedi/drivers/vmk80xx.c
@@ -99,6 +99,8 @@ enum {
#define IC3_VERSION BIT(0)
#define IC6_VERSION BIT(1)
+#define MIN_BUF_SIZE 64
+
enum vmk80xx_model {
VMK8055_MODEL,
VMK8061_MODEL
@@ -687,12 +689,12 @@ static int vmk80xx_alloc_usb_buffers(str
struct vmk80xx_private *devpriv = dev->private;
size_t size;
- size = usb_endpoint_maxp(devpriv->ep_rx);
+ size = max(usb_endpoint_maxp(devpriv->ep_rx), MIN_BUF_SIZE);
devpriv->usb_rx_buf = kzalloc(size, GFP_KERNEL);
if (!devpriv->usb_rx_buf)
return -ENOMEM;
- size = usb_endpoint_maxp(devpriv->ep_tx);
+ size = max(usb_endpoint_maxp(devpriv->ep_rx), MIN_BUF_SIZE);
devpriv->usb_tx_buf = kzalloc(size, GFP_KERNEL);
if (!devpriv->usb_tx_buf)
return -ENOMEM;
Patches currently in stable-queue which might be from johan@xxxxxxxxxx are
queue-4.4/comedi-ni_usb6501-fix-null-deref-in-command-paths.patch
queue-4.4/comedi-dt9812-fix-dma-buffers-on-stack.patch
queue-4.4/staging-r8712u-fix-control-message-timeout.patch
queue-4.4/comedi-vmk80xx-fix-bulk-buffer-overflow.patch
queue-4.4/comedi-vmk80xx-fix-transfer-buffer-overflows.patch
queue-4.4/comedi-vmk80xx-fix-bulk-and-interrupt-message-timeouts.patch
queue-4.4/rsi-fix-control-message-timeout.patch
queue-4.4/staging-rtl8192u-fix-control-message-timeouts.patch
queue-4.4/net-hso-register-netdev-later-to-avoid-a-race-condition.patch
