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Fencer Vulns
high 7.8

CVE-2025-40290 json

xsk: avoid data corruption on cq descriptor number

published 2025-12-08 11 mo ago modified 2026-10-14 25 d ago also EUVD-2025-201616

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

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

xsk: avoid data corruption on cq descriptor number

Since commit 30f241fcf52a ("xsk: Fix immature cq descriptor production"), the descriptor number is stored in skb control block and xsk_cq_submit_addr_locked() relies on it to put the umem addrs onto pool's completion queue.

skb control block shouldn't be used for this purpose as after transmit xsk doesn't have control over it and other subsystems could use it. This leads to the following kernel panic due to a NULL pointer dereference.

BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 2 UID: 1 PID: 927 Comm: p4xsk.bin Not tainted 6.16.12+deb14-cloud-amd64 #1 PREEMPT(lazy) Debian 6.16.12-1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 RIP: 0010:xsk_destruct_skb+0xd0/0x180 [...] Call Trace: <IRQ> ? napi_complete_done+0x7a/0x1a0 ip_rcv_core+0x1bb/0x340 ip_rcv+0x30/0x1f0 __netif_receive_skb_one_core+0x85/0xa0 process_backlog+0x87/0x130 __napi_poll+0x28/0x180 net_rx_action+0x339/0x420 handle_softirqs+0xdc/0x320 ? handle_edge_irq+0x90/0x1e0 do_softirq.part.0+0x3b/0x60 </IRQ> <TASK> __local_bh_enable_ip+0x60/0x70 __dev_direct_xmit+0x14e/0x1f0 __xsk_generic_xmit+0x482/0xb70 ? __remove_hrtimer+0x41/0xa0 ? __xsk_generic_xmit+0x51/0xb70 ? _raw_spin_unlock_irqrestore+0xe/0x40 xsk_sendmsg+0xda/0x1c0 __sys_sendto+0x1ee/0x200 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x84/0x2f0 ? __pfx_pollwake+0x10/0x10 ? __rseq_handle_notify_resume+0xad/0x4c0 ? restore_fpregs_from_fpstate+0x3c/0x90 ? switch_fpu_return+0x5b/0xe0 ? do_syscall_64+0x204/0x2f0 ? do_syscall_64+0x204/0x2f0 ? do_syscall_64+0x204/0x2f0 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> [...] Kernel panic - not syncing: Fatal exception in interrupt Kernel Offset: 0x1c000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)

Instead use the skb destructor_arg pointer along with pointer tagging. As pointers are always aligned to 8B, use the bottom bit to indicate whether this a single address or an allocated struct containing several addresses.

Patch / fix

  • Linux Linux 6.17, 6.17.11, 6.18
  • linux Debian 14 6.17.11-1

debian advisories DEBIAN-CVE-2025-40290

  • linux Ubuntu 25.10 6.17.0-19.19
  • linux-aws Ubuntu 25.10 6.17.0-1009.9
  • linux-gcp Ubuntu 25.10 6.17.0-1009.9
  • linux-azure Ubuntu 25.10 6.17.0-1010.10
  • linux-raspi Ubuntu 25.10 6.17.0-1010.10
  • linux-riscv Ubuntu 25.10 6.17.0-19.19.1
  • linux-oracle Ubuntu 25.10 6.17.0-1009.9
  • linux-aws-6.17 Ubuntu 24.04 LTS 6.17.0-1009.9~24.04.2

ubuntu advisories UBUNTU-CVE-2025-40290

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

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-2025-40290 updated

kernel: xsk: avoid data corruption on cq descriptor number

  • 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 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

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.