e32a291736
commit 97367c97226aab8b298ada954ce12659ee3ad2a4 upstream. It turned out that the current implementation of the port subscription is racy. The subscription contains two linked lists, and we have to add to or delete from both lists. Since both connection and disconnection procedures perform the same order for those two lists (i.e. src list, then dest list), when a deletion happens during a connection procedure, the src list may be deleted before the dest list addition completes, and this may lead to a use-after-free or an Oops, even though the access to both lists are protected via mutex. The simple workaround for this race is to change the access order for the disconnection, namely, dest list, then src list. This assures that the connection has been established when disconnecting, and also the concurrent deletion can be avoided. Reported-and-tested-by: folkert <folkert@vanheusden.com> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210801182754.GP890690@belle.intranet.vanheusden.com Link: https://lore.kernel.org/r/20210803114312.2536-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.