6311071a05
nl80211_parse_mbssid_elems() uses a u8 variable num_elems to count the number of MBSSID elements in the nested netlink attribute attrs, which can lead to an integer overflow if a user of the nl80211 interface specifies 256 or more elements in the corresponding attribute in userspace. The integer overflow can lead to a heap buffer overflow as num_elems determines the size of the trailing array in elems, and this array is thereafter written to for each element in attrs. Note that this vulnerability only affects devices with the wiphy->mbssid_max_interfaces member set for the wireless physical device struct in the device driver, and can only be triggered by a process with CAP_NET_ADMIN capabilities. Fix this by checking for a maximum of 255 elements in attrs. Cc: stable@vger.kernel.org Fixes: dc1e3cb8da8b ("nl80211: MBSSID and EMA support in AP mode") Signed-off-by: Keith Yeo <keithyjy@gmail.com> Link: https://lore.kernel.org/r/20230731034719.77206-1-keithyjy@gmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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.