ccf8dbcd06
In the quest to remove all stack VLA usage from the kernel[1], this allocates the maximum size expected for all possible types and adds sanity-checks at both registration and usage to make sure nothing gets out of sync. This matches the proposed VLA solution for nfnetlink[2]. The values chosen here were based on finding assignments for .maxtype and .slave_maxtype and manually counting the enums: slave_maxtype (max 33): IFLA_BRPORT_MAX 33 IFLA_BOND_SLAVE_MAX 9 maxtype (max 45): IFLA_BOND_MAX 28 IFLA_BR_MAX 45 __IFLA_CAIF_HSI_MAX 8 IFLA_CAIF_MAX 4 IFLA_CAN_MAX 16 IFLA_GENEVE_MAX 12 IFLA_GRE_MAX 25 IFLA_GTP_MAX 5 IFLA_HSR_MAX 7 IFLA_IPOIB_MAX 4 IFLA_IPTUN_MAX 21 IFLA_IPVLAN_MAX 3 IFLA_MACSEC_MAX 15 IFLA_MACVLAN_MAX 7 IFLA_PPP_MAX 2 __IFLA_RMNET_MAX 4 IFLA_VLAN_MAX 6 IFLA_VRF_MAX 2 IFLA_VTI_MAX 7 IFLA_VXLAN_MAX 28 VETH_INFO_MAX 2 VXCAN_INFO_MAX 2 This additionally changes maxtype and slave_maxtype fields to unsigned, since they're only ever using positive values. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com [2] https://patchwork.kernel.org/patch/10439647/ Signed-off-by: Kees Cook <keescook@chromium.org> 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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.