0fca5ed4be
[ Upstream commit 09d88791c7cd888d5195c84733caf9183dcfbd16 ]
The bpf_redirect_info is shared between the SKB and XDP redirect paths,
and the two paths use the same numeric flag values in the ri->flags
field (specifically, BPF_F_BROADCAST == BPF_F_NEXTHOP). This means that
if skb bpf_redirect_neigh() is used with a non-NULL params argument and,
subsequently, an XDP redirect is performed using the same
bpf_redirect_info struct, the XDP path will get confused and end up
crashing, which syzbot managed to trigger.
With the stack-allocated bpf_redirect_info, the structure is no longer
shared between the SKB and XDP paths, so the crash doesn't happen
anymore. However, different code paths using identically-numbered flag
values in the same struct field still seems like a bit of a mess, so
this patch cleans that up by moving the flag definitions together and
redefining the three flags in BPF_F_REDIRECT_INTERNAL to not overlap
with the flags used for XDP. It also adds a BUILD_BUG_ON() check to make
sure the overlap is not re-introduced by mistake.
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.