c381527918
If qdisc_create_dflt() fails, it returns NULL. With CONFIG_NET_SCHED
enabled, the check qdisc != &noop_qdisc passes and qdisc will be passed
to qdisc_hash_add(), which dereferences it.
This assignment was present in the upstream commit 5891cd5ec46c2
("net_sched: add __rcu annotation to netdev->qdisc") but was missed in
the backport 22d95b5449249 ("net_sched: add __rcu annotation to
netdev->qdisc"), perhaps due to merge conflicts. dev->qdisc is
&noop_qdisc by default and if qdisc_create_dflt() fails, this assignment
will make sure qdisc == &noop_qdisc and no NULL dereference will take
place.
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.
Fixes: 22d95b5449249 ("net_sched: add __rcu annotation to netdev->qdisc")
Signed-off-by: Pratyush Yadav <ptyadav@amazon.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.