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Fencer Vulns
high 7.5

CVE-2026-46114 json

RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads

published 2026-05-28 5 mo ago modified 2026-10-19 20 d ago also EUVD-2026-32873

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 40%
public exploits
0
none known

Summary

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

RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads

atomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c unconditionally dereferences 8 bytes at payload_addr(pkt):

value = *(u64 *)payload_addr(pkt);

check_rkey() previously accepted an ATOMIC_WRITE request with pktlen == resid == 0 because the length validation only compared pktlen against resid. A remote initiator that sets the RETH length to 0 therefore reaches atomic_write_reply() with a zero-byte logical payload, and the responder reads sizeof(u64) bytes from past the logical end of the packet into skb->head tailroom, then writes those 8 bytes into the attacker's MR via rxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel tailroom per probe (the other 4 bytes are the packet's own trailing ICRC).

IBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is protocol-invalid. Hoist a strict length check into check_rkey() so the responder never reaches the unchecked dereference, and keep the existing WRITE-family length logic for the normal RDMA WRITE path.

Reproduced on mainline with an unmodified rxe driver: a sustained zero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer bytes into the attacker's MR, including recognisable kernel strings and partial kernel-direct-map pointer words. With this patch applied the responder rejects the PDU and the MR stays all-zero.

Patch / fix

  • Linux Linux 6.6.140, 6.12.88, 6.18.30, 7.0.7, 7.1
  • linux Debian 13 6.12.88-1
  • linux Debian 14 7.0.7-1

debian advisories DEBIAN-CVE-2026-46114

  • linux Ubuntu 24.04 LTS 6.8.0-136.136
  • linux Ubuntu 26.04 LTS 7.0.0-28.28
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1061.64
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1064.72
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1008.8
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1059.67
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1003.4

ubuntu advisories UBUNTU-CVE-2026-46114

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 RHEL 9 5.14.0-687.49.1.el9_8
  • rv RHEL 9 5.14.0-687.49.1.el9_8
  • perf RHEL 9 5.14.0-687.49.1.el9_8
  • rtla RHEL 9 5.14.0-687.49.1.el9_8
  • libperf RHEL 9 5.14.0-687.49.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.49.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.49.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.49.1.el9_8

red hat advisories RHSA-2026:77219RHSA-2026:77218RHSA-2026:68570

  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-48.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-48.1
  • kernel-rt Real Time Module 15 SP7 6.4.0-150700.7.59.2
  • kernel-syms-rt Real Time Module 15 SP7 6.4.0-150700.7.59.1
  • kernel-source-rt Real Time Module 15 SP7 6.4.0-150700.7.59.2
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.60.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.60.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.60.1

suse advisories SUSE-SU-2026:22433-1SUSE-SU-2026:22458-1SUSE-SU-2026:2591-1SUSE-SU-2026:2482-1SUSE-SU-2026:22108-1SUSE-SU-2026:22137-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.35.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.35.1

opensuse advisories openSUSE-SU-2026:20965-1openSUSE-SU-2026:10954-1

  • kernel AlmaLinux 9 5.14.0-687.49.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.49.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.49.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.49.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.49.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.49.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.49.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.49.1.el9_8

almalinux advisories ALSA-2026:68570

  • kernel Rocky Linux 9 5.14.0-687.49.1.el9_8

rocky linux advisories RLSA-2026:68570

  • kernel Azure Linux 3.0 6.6.141.1-1

azure linux advisories AZL-89115

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2026-46114 updated cvss 7.0

kernel: RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads

  • Red Hat CodeReady Linux Builder EUS (v.9.6) libperf 5.14.0-570.147.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.147.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.147.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.147.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.147.1.el9_6
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.49.1.el9_8, perf 5.14.0-687.49.1.el9_8, rtla 5.14.0-687.49.1.el9_8, python3-perf 5.14.0-687.49.1.el9_8, kernel-devel-matched 5.14.0-687.49.1.el9_8, kernel-64k-devel-matched 5.14.0-687.49.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:68570
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) rv 5.14.0-427.154.1.el9_4, perf 5.14.0-427.154.1.el9_4, rtla 5.14.0-427.154.1.el9_4, kernel-devel-matched 5.14.0-427.154.1.el9_4, kernel-64k-devel-matched 5.14.0-427.154.1.el9_4, kernel-debug-devel-matched 5.14.0-427.154.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:77218
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) rv 5.14.0-570.147.1.el9_6, perf 5.14.0-570.147.1.el9_6, rtla 5.14.0-570.147.1.el9_6, python3-perf 5.14.0-570.147.1.el9_6, kernel-devel-matched 5.14.0-570.147.1.el9_6, kernel-64k-devel-matched 5.14.0-570.147.1.el9_6, +7 more
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.49.1.el9_8, kernel-64k 5.14.0-687.49.1.el9_8, kernel-core 5.14.0-687.49.1.el9_8, kernel-tools 5.14.0-687.49.1.el9_8, kernel-modules 5.14.0-687.49.1.el9_8, kernel-64k-core 5.14.0-687.49.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:68570
  • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool 7.3.0-427.154.1.el9_4, kernel 5.14.0-427.154.1.el9_4, kernel-64k 5.14.0-427.154.1.el9_4, kernel-core 5.14.0-427.154.1.el9_4, kernel-tools 5.14.0-427.154.1.el9_4, python3-perf 5.14.0-427.154.1.el9_4, +28 more
    fixed: vendor fix RHSA-2026:77218
  • Red Hat Enterprise Linux BaseOS EUS (v.9.6) kernel 5.14.0-570.147.1.el9_6, kernel-64k 5.14.0-570.147.1.el9_6, kernel-core 5.14.0-570.147.1.el9_6, kernel-tools 5.14.0-570.147.1.el9_6, kernel-modules 5.14.0-570.147.1.el9_6, kernel-64k-core 5.14.0-570.147.1.el9_6, +27 more
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.49.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.49.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.49.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.49.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.49.1.el9_8 Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.49.1.el9_8, kernel-rt-64k 5.14.0-687.49.1.el9_8, kernel-rt-core 5.14.0-687.49.1.el9_8, kernel-rt-modules 5.14.0-687.49.1.el9_8, kernel-rt-64k-core 5.14.0-687.49.1.el9_8, kernel-rt-debug-core 5.14.0-687.49.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:68570
show 6 more
  • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt 5.14.0-427.154.1.el9_4, kernel-rt-core 5.14.0-427.154.1.el9_4, kernel-rt-modules 5.14.0-427.154.1.el9_4, kernel-rt-debug-core 5.14.0-427.154.1.el9_4, kernel-rt-modules-core 5.14.0-427.154.1.el9_4, kernel-rt-debug-modules 5.14.0-427.154.1.el9_4, +4 more
    fixed: vendor fix RHSA-2026:77218
  • Red Hat Enterprise Linux Real Time EUS (v.9.6) kernel-rt 5.14.0-570.147.1.el9_6, kernel-rt-64k 5.14.0-570.147.1.el9_6, kernel-rt-core 5.14.0-570.147.1.el9_6, kernel-rt-modules 5.14.0-570.147.1.el9_6, kernel-rt-64k-core 5.14.0-570.147.1.el9_6, kernel-rt-debug-core 5.14.0-570.147.1.el9_6, +14 more
    fixed: vendor fix RHSA-2026:77219
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.49.1.el9_8, kernel-rt-core 5.14.0-687.49.1.el9_8, kernel-rt-modules 5.14.0-687.49.1.el9_8, kernel-rt-debug-core 5.14.0-687.49.1.el9_8, kernel-rt-modules-core 5.14.0-687.49.1.el9_8, kernel-rt-debug-modules 5.14.0-687.49.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:68570
  • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt 5.14.0-427.154.1.el9_4, kernel-rt-kvm 5.14.0-427.154.1.el9_4, kernel-rt-core 5.14.0-427.154.1.el9_4, kernel-rt-modules 5.14.0-427.154.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.154.1.el9_4, kernel-rt-debug-core 5.14.0-427.154.1.el9_4, +6 more
    fixed: vendor fix RHSA-2026:77218
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.6) kernel-rt 5.14.0-570.147.1.el9_6, kernel-rt-kvm 5.14.0-570.147.1.el9_6, kernel-rt-core 5.14.0-570.147.1.el9_6, kernel-rt-modules 5.14.0-570.147.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.147.1.el9_6, kernel-rt-debug-core 5.14.0-570.147.1.el9_6, +6 more
    fixed: vendor fix RHSA-2026:77219
  • 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 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 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
23 d ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 40% 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:H/I:N/A:N

Affected products

  • Linux Linux

Classification

Weakness
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.