[SRU][J][PATCH 0/1] CVE-2022-49858

[Cengiz Can]

https://ubuntu.com/security/CVE-2022-49858

[ Impact ]

In the Linux kernel, the following vulnerability has been resolved:

octeontx2-pf: Fix SQE threshold checking

Current way of checking available SQE count which is based on HW updated SQB
count could result in driver submitting an SQE even before CQE for the
previously transmitted SQE at the same index is processed in NAPI resulting
losing SKB pointers, hence a leak. Fix this by checking a consumer index which
is updated once CQE is processed.

[ Fix ]

jammy/linux: backported from f0dfc4c88ef3

The backport drops the CQ_XDP branch in otx2_tx_napi_handler because this
tree lacks XDP TX support (no CQ_XDP enum or otx2_xdp_snd_pkt_handler). The
sq/cons_head SQE-threshold fix is preserved, calling otx2_snd_pkt_handler
with the computed sq.

[ Test Plan ]

Build and boot tested.

[ Where Problems Could Occur ]

A regression would most likely surface on systems using Marvell OcteonTX2
network interfaces driven by the octeontx2-pf driver, specifically under
heavy transmit workloads where the send-queue threshold logic is exercised.
An incorrect fix could affect packet transmission or the associated SKB
accounting on that hardware. Systems without Marvell OcteonTX2 NICs do not
use this driver and are not affected.

[ Other Info ]

Kybele flow-v11-25-ga27c0fa6. Reference: 3b90db0e/v1