2bd8534a1b
commit a368ecde8a5055b627749b09c6218ef793043e47 upstream.
Syzbot has identified a bug in usbcore (see the Closes: tag below)
caused by our assumption that the reserved bits in an endpoint
descriptor's bEndpointAddress field will always be 0. As a result of
the bug, the endpoint_is_duplicate() routine in config.c (and possibly
other routines as well) may believe that two descriptors are for
distinct endpoints, even though they have the same direction and
endpoint number. This can lead to confusion, including the bug
identified by syzbot (two descriptors with matching endpoint numbers
and directions, where one was interrupt and the other was bulk).
To fix the bug, we will clear the reserved bits in bEndpointAddress
when we parse the descriptor. (Note that both the USB-2.0 and USB-3.1
specs say these bits are "Reserved, reset to zero".) This requires us
to make a copy of the descriptor earlier in usb_parse_endpoint() and
use the copy instead of the original when checking for duplicates.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: syzbot+8693a0bb9c10b554272a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/0000000000003d868e061bc0f554@google.com/
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.