[ Upstream commit d482c7bb0541d19dea8bff437a9f3c5563b5b2d2 ]

Endpoints with a maxpacket length of 0 are probably useless.  They
can't transfer any data, and it's not at all unlikely that an HCD will
crash or hang when trying to handle an URB for such an endpoint.

Currently the USB core does not check for endpoints having a maxpacket
value of 0.  This patch adds a check, printing a warning and skipping
over any endpoints it catches.

Now, the USB spec does not rule out endpoints having maxpacket = 0.
But since they wouldn't have any practical use, there doesn't seem to
be any good reason for us to accept them.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>

Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1910281050420.1485-100000@iolanthe.rowland.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 3dd550a2d36596a1b0ee7955da3b611c031d3873 upstream.

The syzbot fuzzer provoked a slab-out-of-bounds error in the USB core:

BUG: KASAN: slab-out-of-bounds in memcmp+0xa6/0xb0 lib/string.c:904
Read of size 1 at addr ffff8881d175bed6 by task kworker/0:3/2746

CPU: 0 PID: 2746 Comm: kworker/0:3 Not tainted 5.3.0-rc5+ #28
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xca/0x13e lib/dump_stack.c:113
  print_address_description+0x6a/0x32c mm/kasan/report.c:351
  __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
  kasan_report+0xe/0x12 mm/kasan/common.c:612
  memcmp+0xa6/0xb0 lib/string.c:904
  memcmp include/linux/string.h:400 [inline]
  descriptors_changed drivers/usb/core/hub.c:5579 [inline]
  usb_reset_and_verify_device+0x564/0x1300 drivers/usb/core/hub.c:5729
  usb_reset_device+0x4c1/0x920 drivers/usb/core/hub.c:5898
  rt2x00usb_probe+0x53/0x7af
drivers/net/wireless/ralink/rt2x00/rt2x00usb.c:806

The error occurs when the descriptors_changed() routine (called during
a device reset) attempts to compare the old and new BOS and capability
descriptors.  The length it uses for the comparison is the
wTotalLength value stored in BOS descriptor, but this value is not
necessarily the same as the length actually allocated for the
descriptors.  If it is larger the routine will call memcmp() with a
length that is too big, thus reading beyond the end of the allocated
region and leading to this fault.

The kernel reads the BOS descriptor twice: first to get the total
length of all the capability descriptors, and second to read it along
with all those other descriptors.  A malicious (or very faulty) device
may send different values for the BOS descriptor fields each time.
The memory area will be allocated using the wTotalLength value read
the first time, but stored within it will be the value read the second
time.

To prevent this possibility from causing any errors, this patch
modifies the BOS descriptor after it has been read the second time:
It sets the wTotalLength field to the actual length of the descriptors
that were read in and validated.  Then the memcpy() call, or any other
code using these descriptors, will be able to rely on wTotalLength
being valid.

Reported-and-tested-by: syzbot+35f4d916c623118d576e@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1909041154260.1722-100000@iolanthe.rowland.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The syzkaller USB fuzzer found a slab-out-of-bounds write bug in the
USB core, caused by a failure to check the actual size of a BOS
descriptor.  This patch adds a check to make sure the descriptor is at
least as large as it is supposed to be, so that the code doesn't
inadvertently access memory beyond the end of the allocated region
when assigning to dev->bos->desc->bNumDeviceCaps later on.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: syzbot+71f1e64501a309fcc012@syzkaller.appspotmail.com
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    struct boo entry[];
};

size = sizeof(struct foo) + count * sizeof(struct boo);
instance = kzalloc(size, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

Notice that, in this case, variable len is not necessary, hence
it is removed.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

It is better to initialize the variable 'cfgno' in the for loop than
at the current place.

Signed-off-by: Suwan Kim <suwan.kim027@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

It is better to initialize the return value "result" to -ENOMEM
than to 0. And because "result" takes the return value of
usb_parse_configuration() which returns 0 for success, setting
"result" to 0 at before and after of the for loop is unnecessary.

Signed-off-by: Suwan Kim <suwan.kim027@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Some non-compliant high-speed USB devices have bulk endpoints with a
1024-byte maxpacket size.  Although such endpoints don't work with
xHCI host controllers, they do work with EHCI controllers.  We used to
accept these invalid sizes (with a warning), but we no longer do
because of an unintentional change introduced by commit aed9d65ac327
("USB: validate wMaxPacketValue entries in endpoint descriptors").

This patch restores the old behavior, so that people with these
peculiar devices can use them without patching their kernels by hand.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Elvinas <elvinas@veikia.lt>
Fixes: aed9d65ac327 ("USB: validate wMaxPacketValue entries in endpoint descriptors")
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB 3.1 devices are not detected as 3.1 capable since 4.15-rc3 due to a
off by one in commit 81cf4a45360f ("USB: core: Add type-specific length
check of BOS descriptors")

It uses USB_DT_USB_SSP_CAP_SIZE() to get SSP capability size which takes
the zero based SSAC as argument, not the actual count of sublink speed
attributes.

USB3 spec 9.6.2.5 says "The number of Sublink Speed Attributes = SSAC + 1."

The type-specific length check patch was added to stable and needs to be
fixed there as well

Fixes: 81cf4a45360f ("USB: core: Add type-specific length check of BOS descriptors")
Cc: linux-stable <stable@vger.kernel.org>
CC: Masakazu Mokuno <masakazu.mokuno@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

A malicious USB device with crafted descriptors can cause the kernel
to access unallocated memory by setting the bNumInterfaces value too
high in a configuration descriptor.  Although the value is adjusted
during parsing, this adjustment is skipped in one of the error return
paths.

This patch prevents the problem by setting bNumInterfaces to 0
initially.  The existing code already sets it to the proper value
after parsing is complete.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 32fd87b3bbf5f7a045546401dfe2894dbbf4d8c3.

Alan wrote a better fix for this...

Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>