Linux kernel source tree
Go to file
John Fastabend 9c983fd7cf bpf, sockmap: Attach map progs to psock early for feature probes
commit 38207a5e81 upstream.

When a TCP socket is added to a sock map we look at the programs attached
to the map to determine what proto op hooks need to be changed. Before
the patch in the 'fixes' tag there were only two categories -- the empty
set of programs or a TX policy. In any case the base set handled the
receive case.

After the fix we have an optimized program for receive that closes a small,
but possible, race on receive. This program is loaded only when the map the
psock is being added to includes a RX policy. Otherwise, the race is not
possible so we don't need to handle the race condition.

In order for the call to sk_psock_init() to correctly evaluate the above
conditions all progs need to be set in the psock before the call. However,
in the current code this is not the case. We end up evaluating the
requirements on the old prog state. If your psock is attached to multiple
maps -- for example a tx map and rx map -- then the second update would pull
in the correct maps. But, the other pattern with a single rx enabled map
the correct receive hooks are not used. The result is the race fixed by the
patch in the fixes tag below may still be seen in this case.

To fix we simply set all psock->progs before doing the call into
sock_map_init(). With this the init() call gets the full list of programs
and chooses the correct proto ops on the first iteration instead of
requiring the second update to pull them in. This fixes the race case when
only a single map is used.

Fixes: c5d2177a72 ("bpf, sockmap: Fix race in ingress receive verdict with redirect to self")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211119181418.353932-2-john.fastabend@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 10:57:09 +01:00
arch x86/sme: Explicitly map new EFI memmap table as encrypted 2021-12-14 10:57:08 +01:00
block block: avoid to quiesce queue in elevator_init_mq 2021-12-01 09:04:56 +01:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto crypto: pcrypt - Delay write to padata->info 2021-11-18 19:16:44 +01:00
Documentation docs: accounting: update delay-accounting.rst reference 2021-12-01 09:04:56 +01:00
drivers vrf: don't run conntrack on vrf with !dflt qdisc 2021-12-14 10:57:08 +01:00
fs io-wq: don't retry task_work creation failure on fatal conditions 2021-12-08 09:04:53 +01:00
include bpf, x86: Fix "no previous prototype" warning 2021-12-14 10:57:08 +01:00
init init: make unknown command line param message clearer 2021-11-18 19:17:11 +01:00
ipc shm: extend forced shm destroy to support objects from several IPC nses 2021-11-25 09:48:42 +01:00
kernel sched/uclamp: Fix rq->uclamp_max not set on first enqueue 2021-12-08 09:04:54 +01:00
lib siphash: use _unaligned version by default 2021-12-08 09:04:47 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm hugetlbfs: flush TLBs correctly after huge_pmd_unshare 2021-11-25 09:49:07 +01:00
net bpf, sockmap: Attach map progs to psock early for feature probes 2021-12-14 10:57:09 +01:00
samples samples/bpf: Fix incorrect use of strlen in xdp_redirect_cpu 2021-11-25 09:48:33 +01:00
scripts leaking_addresses: Always print a trailing newline 2021-11-18 19:16:16 +01:00
security selinux: fix NULL-pointer dereference when hashtab allocation fails 2021-11-25 09:49:07 +01:00
sound ASoC: rk817: Add module alias for rk817-codec 2021-12-08 09:04:52 +01:00
tools vrf: don't run conntrack on vrf with !dflt qdisc 2021-12-14 10:57:08 +01:00
usr .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
virt KVM: Ensure local memslot copies operate on up-to-date arch-specific data 2021-12-08 09:04:43 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS drm fixes for 5.15 final 2021-10-28 12:17:01 -07:00
Makefile Linux 5.15.7 2021-12-08 09:04:57 +01:00
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.