[SRU][Jammy-OEM-5.17/OEM-6.0][PATCH 0/2] CVE-2022-4269

[Yuxuan Luo]

[Impact]
A flaw was found in the Linux kernel Traffic Control (TC) subsystem. Using
a specific networking configuration (redirecting egress packets to ingress
using TC action "mirred") a local unprivileged user could trigger a CPU
soft lockup (ABBA deadlock) when the transport protocol in use (TCP or
SCTP) does a retransmission, resulting in a denial of service condition.

[Backport]
For Jammy, there is a build error at `mirred_nest_level` not found. In order to
fix this problem, backport 78dcdffe0418 (“net/sched: act_mirred: better
wording on protection against excessive stack growth”), this commit renamed
some variables, which solves the error of the fix commit.

[Test]
Compile and smoke tested via `sudo tc filter add dev dummy0 protocol ip
pref 100 handle 100 flower`.

[Potential Regression]
Expecting really low potential regression as the two commits only
refactor and add some checks.

Davide Caratti (1):
  act_mirred: use the backlog for nested calls to mirred ingress

 net/sched/act_mirred.c                        |  7 +++
 .../selftests/net/forwarding/tc_actions.sh    | 49 ++++++++++++++++++-
 2 files changed, 55 insertions(+), 1 deletion(-)

-- 
2.34.1