c433570458
There are multiple issues here: 1. After freeing dev->ax25_ptr, we need to set it to NULL otherwise we may use a dangling pointer. 2. There is a race between ax25_setsockopt() and device notifier as reported by syzbot. Close it by holding RTNL lock. 3. We need to test if dev->ax25_ptr is NULL before using it. Reported-and-tested-by: syzbot+ae6bb869cbed29b29040@syzkaller.appspotmail.com Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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.