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Fencer Vulns
high 7.5

CVE-2023-53463 json

ibmvnic: Do not reset dql stats on NON_FATAL err

published 2025-10-01 13 mo ago modified 2026-10-15 24 d ago also EUVD-2025-32808

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 30%
public exploits
0
none known

Summary

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

ibmvnic: Do not reset dql stats on NON_FATAL err

All ibmvnic resets, make a call to netdev_tx_reset_queue() when re-opening the device. netdev_tx_reset_queue() resets the num_queued and num_completed byte counters. These stats are used in Byte Queue Limit (BQL) algorithms. The difference between these two stats tracks the number of bytes currently sitting on the physical NIC. ibmvnic increases the number of queued bytes though calls to netdev_tx_sent_queue() in the drivers xmit function. When, VIOS reports that it is done transmitting bytes, the ibmvnic device increases the number of completed bytes through calls to netdev_tx_completed_queue(). It is important to note that the driver batches its transmit calls and num_queued is increased every time that an skb is added to the next batch, not necessarily when the batch is sent to VIOS for transmission.

Unlike other reset types, a NON FATAL reset will not flush the sub crq tx buffers. Therefore, it is possible for the batched skb array to be partially full. So if there is call to netdev_tx_reset_queue() when re-opening the device, the value of num_queued (0) would not account for the skb's that are currently batched. Eventually, when the batch is sent to VIOS, the call to netdev_tx_completed_queue() would increase num_completed to a value greater than the num_queued. This causes a BUG_ON crash:

ibmvnic 30000002: Firmware reports error, cause: adapter problem. Starting recovery... ibmvnic 30000002: tx error 600 ibmvnic 30000002: tx error 600 ibmvnic 30000002: tx error 600 ibmvnic 30000002: tx error 600 ------------[ cut here ]------------ kernel BUG at lib/dynamic_queue_limits.c:27! Oops: Exception in kernel mode, sig: 5 [....] NIP dql_completed+0x28/0x1c0 LR ibmvnic_complete_tx.isra.0+0x23c/0x420 [ibmvnic] Call Trace: ibmvnic_complete_tx.isra.0+0x3f8/0x420 [ibmvnic] (unreliable) ibmvnic_interrupt_tx+0x40/0x70 [ibmvnic] __handle_irq_event_percpu+0x98/0x270 ---[ end trace ]---

Therefore, do not reset the dql stats when performing a NON_FATAL reset.

Patch / fix

  • Linux Linux 5.15.121, 6.1.39, 6.4.4, 6.5
  • linux Debian 12 6.1.52-1
  • linux Debian 14, Debian 13 6.4.4-1

debian advisories DEBIAN-CVE-2023-53463

  • linux Ubuntu 22.04 LTS 5.15.0-86.96
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1047.52
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1044.52
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1044.49
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1040.43
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1044.49
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1049.56
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1030.35

ubuntu advisories UBUNTU-CVE-2023-53463

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt Real Time Module 15 SP7 6.4.0-150700.7.22.1
  • kernel-syms-rt Real Time Module 15 SP7 6.4.0-150700.7.22.1
  • kernel-source-rt Real Time Module 15 SP7 6.4.0-150700.7.22.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.18.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.18.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.18.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.22.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.22.1

suse advisories SUSE-SU-2025:4141-1SUSE-SU-2025:4132-1SUSE-SU-2025:4057-1SUSE-SU-2025:20870-1SUSE-SU-2025:3761-1SUSE-SU-2025:20898-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-53463 updated cvss 4.7

kernel: ibmvnic: Do not reset dql stats on NON_FATAL err

  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
24 d ago

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 30% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.