abfdd9e2f0
[ Upstream commit 0276af2176c78771da7f311621a25d7608045827 ]
ethtool_set_coalesce() now uses both the .get_coalesce() and
.set_coalesce() callbacks. But the check for their availability is
buggy, so changing the coalesce settings on a device where the driver
provides only _one_ of the callbacks results in a NULL pointer
dereference instead of an -EOPNOTSUPP.
Fix the condition so that the availability of both callbacks is
ensured. This also matches the netlink code.
Note that reproducing this requires some effort - it only affects the
legacy ioctl path, and needs a specific combination of driver options:
- have .get_coalesce() and .coalesce_supported but no
.set_coalesce(), or
- have .set_coalesce() but no .get_coalesce(). Here eg. ethtool doesn't
cause the crash as it first attempts to call ethtool_get_coalesce()
and bails out on error.
Fixes: f3ccfda19319 ("ethtool: extend coalesce setting uAPI with CQE mode")
Cc: Yufeng Mo <moyufeng@huawei.com>
Cc: Huazhong Tan <tanhuazhong@huawei.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Link: https://lore.kernel.org/r/20211126175543.28000-1-jwi@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.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.