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VulnerabilityPublished Updated

CVE-2025-21682: Linux kernel · eth: bnxt: always recalculate features after XDP clearing, fix null-deref

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.3 High · fixed in 6.8.0-1030.32~22.04.1 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.3High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.8.0-1030.32~22.04.1, 6.8.0-1030.35~22.04.1, 6.8.0-1031.33~22.04.1 +31
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 31 Jan 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux@6.8.0-62.65?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-62.65
Fixed in
  • 6.8.0-62.65
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@6.8.0-1030.32?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1030.32
Fixed in
  • 6.8.0-1030.32
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@6.8.0-1030.35?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1030.35
Fixed in
  • 6.8.0-1030.35
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11@6.11.0-1013.13~24.04.1?arch=source&distro=nobleOther threatsAffected
  • <6.11.0-1013.13~24.04.1
Fixed in
  • 6.11.0-1013.13~24.04.1
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia@6.8.0-1018.19?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1018.19
Fixed in
  • 6.8.0-1018.19
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp@6.8.0-1031.33?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1031.33
Fixed in
  • 6.8.0-1031.33

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: eth: bnxt: always recalculate features after XDP clearing, fix null-deref Recalculate features when XDP is detached. Before: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: off [requested on] After: # ip li set dev eth0 xdp obj xdp_dummy.bpf.o sec xdp # ip li set dev eth0 xdp off # ethtool -k eth0 | grep gro rx-gro-hw: on The fact that HW-GRO doesn't get re-enabled automatically is just a minor annoyance. The real issue is that the features will randomly come back during another reconfiguration which just happens to invoke netdev_update_features(). The driver doesn't handle reconfiguring two things at a time very robustly. Starting with commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") we only reconfigure the RSS hash table if the "effective" number of Rx rings has changed. If HW-GRO is enabled "effective" number of rings is 2x what user sees. So if we are in the bad state, with HW-GRO re-enablement "pending" after XDP off, and we lower the rings by / 2 - the HW-GRO rings doing 2x and the ethtool -L doing / 2 may cancel each other out, and the: if (old_rx_rings != bp->hw_resc.resv_rx_rings && condition in __bnxt_reserve_rings() will be false. The RSS map won't get updated, and we'll crash with: BUG: kernel NULL pointer dereference, address: 0000000000000168 RIP: 0010:__bnxt_hwrm_vnic_set_rss+0x13a/0x1a0 bnxt_hwrm_vnic_rss_cfg_p5+0x47/0x180 __bnxt_setup_vnic_p5+0x58/0x110 bnxt_init_nic+0xb72/0xf50 __bnxt_open_nic+0x40d/0xab0 bnxt_open_nic+0x2b/0x60 ethtool_set_channels+0x18c/0x1d0 As we try to access a freed ring. The issue is present since XDP support was added, really, but prior to commit 98ba1d931f61 ("bnxt_en: Fix RSS logic in __bnxt_reserve_rings()") it wasn't causing major issues.

References

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