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Fencer Vulns
high 7.5

CVE-2025-21960 json

eth: bnxt: do not update checksum in bnxt_xdp_build_skb()

published 2025-04-01 19 mo ago modified 2026-08-05 3 mo ago also EUVD-2025-9360

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

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

eth: bnxt: do not update checksum in bnxt_xdp_build_skb()

The bnxt_rx_pkt() updates ip_summed value at the end if checksum offload is enabled. When the XDP-MB program is attached and it returns XDP_PASS, the bnxt_xdp_build_skb() is called to update skb_shared_info. The main purpose of bnxt_xdp_build_skb() is to update skb_shared_info, but it updates ip_summed value too if checksum offload is enabled. This is actually duplicate work.

When the bnxt_rx_pkt() updates ip_summed value, it checks if ip_summed is CHECKSUM_NONE or not. It means that ip_summed should be CHECKSUM_NONE at this moment. But ip_summed may already be updated to CHECKSUM_UNNECESSARY in the XDP-MB-PASS path. So the by skb_checksum_none_assert() WARNS about it.

This is duplicate work and updating ip_summed in the bnxt_xdp_build_skb() is not needed.

Splat looks like: WARNING: CPU: 3 PID: 5782 at ./include/linux/skbuff.h:5155 bnxt_rx_pkt+0x479b/0x7610 [bnxt_en] Modules linked in: bnxt_re bnxt_en rdma_ucm rdma_cm iw_cm ib_cm ib_uverbs veth xt_nat xt_tcpudp xt_conntrack nft_chain_nat xt_MASQUERADE nf_] CPU: 3 UID: 0 PID: 5782 Comm: socat Tainted: G W 6.14.0-rc4+ #27 Tainted: [W]=WARN Hardware name: ASUS System Product Name/PRIME Z690-P D4, BIOS 0603 11/01/2021 RIP: 0010:bnxt_rx_pkt+0x479b/0x7610 [bnxt_en] Code: 54 24 0c 4c 89 f1 4c 89 ff c1 ea 1f ff d3 0f 1f 00 49 89 c6 48 85 c0 0f 84 4c e5 ff ff 48 89 c7 e8 ca 3d a0 c8 e9 8f f4 ff ff <0f> 0b f RSP: 0018:ffff88881ba09928 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 00000000c7590303 RCX: 0000000000000000 RDX: 1ffff1104e7d1610 RSI: 0000000000000001 RDI: ffff8881c91300b8 RBP: ffff88881ba09b28 R08: ffff888273e8b0d0 R09: ffff888273e8b070 R10: ffff888273e8b010 R11: ffff888278b0f000 R12: ffff888273e8b080 R13: ffff8881c9130e00 R14: ffff8881505d3800 R15: ffff888273e8b000 FS: 00007f5a2e7be080(0000) GS:ffff88881ba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff2e708ff8 CR3: 000000013e3b0000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <IRQ> ? __warn+0xcd/0x2f0 ? bnxt_rx_pkt+0x479b/0x7610 ? report_bug+0x326/0x3c0 ? handle_bug+0x53/0xa0 ? exc_invalid_op+0x14/0x50 ? asm_exc_invalid_op+0x16/0x20 ? bnxt_rx_pkt+0x479b/0x7610 ? bnxt_rx_pkt+0x3e41/0x7610 ? __pfx_bnxt_rx_pkt+0x10/0x10 ? napi_complete_done+0x2cf/0x7d0 __bnxt_poll_work+0x4e8/0x1220 ? __pfx___bnxt_poll_work+0x10/0x10 ? __pfx_mark_lock.part.0+0x10/0x10 bnxt_poll_p5+0x36a/0xfa0 ? __pfx_bnxt_poll_p5+0x10/0x10 __napi_poll.constprop.0+0xa0/0x440 net_rx_action+0x899/0xd00 ...

Following ping.py patch adds xdp-mb-pass case. so ping.py is going to be able to reproduce this issue.

Patch / fix

  • Linux Linux 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14
  • linux Debian 12 6.1.133-1
  • linux Debian 14, Debian 13 6.12.20-1

debian advisories DEBIAN-CVE-2025-21960

  • linux Ubuntu 24.04 LTS 6.8.0-84.84
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1039.41
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1040.42
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1036.40
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1037.37
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1038.44
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1023.25
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1039.43

ubuntu advisories UBUNTU-CVE-2025-21960

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-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.39.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.39.1
  • kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.39.1
  • kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.39.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1

suse advisories SUSE-SU-2025:01967-1SUSE-SU-2025:01964-1SUSE-SU-2025:01951-1SUSE-SU-2025:01919-1SUSE-SU-2025:01707-1SUSE-SU-2025:01614-1

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-2025-21960 updated cvss 5.7

kernel: eth: bnxt: do not update checksum in bnxt_xdp_build_skb()

  • Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available “To mitigate this issue, prevent module bnxt_en from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • 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 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
    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

Exploit prediction

0.53% chance of exploitation in the next 30 days, higher than 45% 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.