NULL pointer dereference in Linux kernel - CVE-2026-52939

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Main Vulnerability Database Vulnerabilities #VU135436

NULL pointer dereference in Linux kernel - CVE-2026-52939

Published: June 25, 2026


Vulnerability identifier: #VU135436
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-52939
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a NULL pointer dereference in rds_ib_send_cqe_handler() and rds_ib_send_unmap_op() when processing an atomic cmsg over an active RDS/IB connection. A local user can send a crafted AF_RDS sendmsg() request to cause a denial of service.

On hardware that natively accepts masked atomic operations, no additional setup is required.


Affected software

Linux kernel
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Workstation Extension 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Micro
SUSE Linux Micro Extras
SUSE Linux Enterprise Live Patching
Public Cloud Module
Legacy Module
Development Tools Module
Basesystem Module
SUSE Real Time Module
Ubuntu
kgraft-patch-4_12_14-122_328-default
kernel-livepatch-SLE15-SP7-RT_Update_20-debugsource
kernel-livepatch-6_4_0-150700_7_75-rt-debuginfo
kernel-livepatch-6_4_0-150700_7_75-rt
kernel-livepatch-SLE15-SP7_Update_21-debugsource
kernel-livepatch-6_4_0-150700_53_81-default-debuginfo
kernel-livepatch-6_4_0-150700_53_81-default
cluster-md-kmp-default-debuginfo
kernel-default-base
kernel-default-devel
cluster-md-kmp-default
gfs2-kmp-default
ocfs2-kmp-default-debuginfo
gfs2-kmp-default-debuginfo
dlm-kmp-default
ocfs2-kmp-default
kernel-default-base-debuginfo
dlm-kmp-default-debuginfo
kernel-syms
kernel-source
kernel-default-kgraft
kernel-default-debuginfo
kernel-default-kgraft-devel
kernel-default-debugsource
kernel-default
kernel-devel
kernel-macros
kernel-default-man
kernel-default-devel-debuginfo
kernel-64kb
kernel-64kb-debugsource
kernel-64kb-devel
kernel-obs-build
kernel-obs-build-debugsource
kernel-kvmsmall-debuginfo
kernel-kvmsmall-debugsource
kernel-default-livepatch
kernel-rt-livepatch
kernel-rt-debugsource
kernel-rt-debuginfo
kernel-kvmsmall
kernel-source-rt
kernel-devel-rt
kernel-rt
kernel-syms-rt
ocfs2-kmp-rt
gfs2-kmp-rt-debuginfo
dlm-kmp-rt
kernel-rt-devel
cluster-md-kmp-rt
cluster-md-kmp-rt-debuginfo
dlm-kmp-rt-debuginfo
gfs2-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-rt-devel-debuginfo
kernel-azure-devel-debuginfo
kernel-default-livepatch-devel
kernel-azure
kernel-azure-devel
kernel-azure-debugsource
kernel-default-extra
kernel-default-extra-debuginfo
reiserfs-kmp-default-debuginfo
kernel-azure-debuginfo
reiserfs-kmp-default
kernel-docs
kernel-64kb-devel-debuginfo
kernel-zfcpdump
kernel-zfcpdump-debugsource
kernel-zfcpdump-debuginfo
kernel-64kb-debuginfo
linux (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-52939

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kgraft-patch-4_12_14-122_328-default - update to 1-8.5.1
kernel-livepatch-SLE15-SP7-RT_Update_20-debugsource - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_75-rt-debuginfo - update to 1-150700.1.3.1
kernel-livepatch-6_4_0-150700_7_75-rt - update to 1-150700.1.3.1
kernel-livepatch-SLE15-SP7_Update_21-debugsource - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_81-default-debuginfo - update to 1-150700.15.3.1
kernel-livepatch-6_4_0-150700_53_81-default - update to 1-150700.15.3.1
cluster-md-kmp-default-debuginfo - addressed in versions 4.12.14-122.328.1, 6.4.0-150700.53.81.1
kernel-default-base - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1.21.35, 6.4.0-52.1.21.36, 6.4.0-150700.53.81.1.150700.17.45.1
kernel-default-devel - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
cluster-md-kmp-default - addressed in versions 4.12.14-122.328.1, 6.4.0-150700.53.81.1
gfs2-kmp-default - addressed in versions 4.12.14-122.328.1, 6.4.0-150700.53.81.1
ocfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.328.1, 6.4.0-150700.53.81.1
gfs2-kmp-default-debuginfo - addressed in versions 4.12.14-122.328.1, 6.4.0-150700.53.81.1
dlm-kmp-default - addressed in versions 4.12.14-122.328.1, 6.4.0-150700.53.81.1
ocfs2-kmp-default - addressed in versions 4.12.14-122.328.1, 6.4.0-150700.53.81.1
kernel-default-base-debuginfo - update to 4.12.14-122.328.1
dlm-kmp-default-debuginfo - addressed in versions 4.12.14-122.328.1, 6.4.0-150700.53.81.1
kernel-syms - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-source - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-default-kgraft - update to 4.12.14-122.328.1
kernel-default-debuginfo - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-default-kgraft-devel - update to 4.12.14-122.328.1
kernel-default-debugsource - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-default - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-devel - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-macros - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-default-man - update to 4.12.14-122.328.1
kernel-default-devel-debuginfo - addressed in versions 4.12.14-122.328.1, 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-64kb - addressed in versions 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-64kb-debugsource - addressed in versions 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-64kb-devel - addressed in versions 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-obs-build - addressed in versions 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-obs-build-debugsource - addressed in versions 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-kvmsmall-debuginfo - update to 6.4.0-52.1
kernel-kvmsmall-debugsource - update to 6.4.0-52.1
kernel-default-livepatch - addressed in versions 6.4.0-52.1, 6.4.0-150700.53.81.1
kernel-rt-livepatch - update to 6.4.0-52.1
kernel-rt-debugsource - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-rt-debuginfo - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-kvmsmall - update to 6.4.0-52.1
kernel-source-rt - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-devel-rt - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-rt - addressed in versions 6.4.0-52.1, 6.4.0-150700.7.75.1
kernel-syms-rt - update to 6.4.0-150700.7.75.1
ocfs2-kmp-rt - update to 6.4.0-150700.7.75.1
gfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.75.1
dlm-kmp-rt - update to 6.4.0-150700.7.75.1
kernel-rt-devel - update to 6.4.0-150700.7.75.1
cluster-md-kmp-rt - update to 6.4.0-150700.7.75.1
cluster-md-kmp-rt-debuginfo - update to 6.4.0-150700.7.75.1
dlm-kmp-rt-debuginfo - update to 6.4.0-150700.7.75.1
gfs2-kmp-rt - update to 6.4.0-150700.7.75.1
ocfs2-kmp-rt-debuginfo - update to 6.4.0-150700.7.75.1
kernel-rt-devel-debuginfo - update to 6.4.0-150700.7.75.1
kernel-azure-devel-debuginfo - update to 6.4.0-150700.53.81.1
kernel-default-livepatch-devel - update to 6.4.0-150700.53.81.1
kernel-azure - update to 6.4.0-150700.53.81.1
kernel-azure-devel - update to 6.4.0-150700.53.81.1
kernel-azure-debugsource - update to 6.4.0-150700.53.81.1
kernel-default-extra - update to 6.4.0-150700.53.81.1
kernel-default-extra-debuginfo - update to 6.4.0-150700.53.81.1
reiserfs-kmp-default-debuginfo - update to 6.4.0-150700.53.81.1
kernel-azure-debuginfo - update to 6.4.0-150700.53.81.1
reiserfs-kmp-default - update to 6.4.0-150700.53.81.1
kernel-docs - update to 6.4.0-150700.53.81.1
kernel-64kb-devel-debuginfo - update to 6.4.0-150700.53.81.1
kernel-zfcpdump - update to 6.4.0-150700.53.81.1
kernel-zfcpdump-debugsource - update to 6.4.0-150700.53.81.1
kernel-zfcpdump-debuginfo - update to 6.4.0-150700.53.81.1
kernel-64kb-debuginfo - update to 6.4.0-150700.53.81.1
linux (Ubuntu package) - addressed in versions 5.15.0-195.205~20.04.1, 5.15.0-195.205, 5.15.0-198.208~20.04.1, 5.15.0-198.208+fips1, 5.15.0-1080.84, 5.15.0-1100.108, 5.15.0-1109.111, 5.15.0-1109.114, 5.15.0-1111.115~20.04.1, 5.15.0-1111.115, 5.15.0-1112.118~20.04.1, 5.15.0-1112.118, 5.15.0-1113.119, 5.15.0-1114.120, 5.15.0-1116.125~20.04.1, 5.15.0-1117.124~20.04.1, 5.15.0-1117.124, 5.15.0-1117.124+fips1, 5.15.0-1122.131~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1123.132, 5.15.0-1123.132+fips1, 5.15.0.195.160, 5.15.0.195.205~20.04.1, 5.15.0.198.114, 5.15.0.198.171, 5.15.0.198.208~20.04.1, 5.15.0.1080.83~20.04.1, 5.15.0.1100.99, 5.15.0.1109.105, 5.15.0.1109.113, 5.15.0.1111.108, 5.15.0.1111.115~20.04.1, 5.15.0.1112.111, 5.15.0.1112.118~20.04.1, 5.15.0.1113.112, 5.15.0.1114.110, 5.15.0.1116.120, 5.15.0.1117.113, 5.15.0.1117.120, 5.15.0.1117.124~20.04.1, 5.15.0.1122.131~20.04.1, 5.15.0.1123.107, 5.15.0.1123.121, 5.15.0.1123.132~20.04.1, 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1012.12
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112, 7.0.0-1018.18
linux-oracle-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.120~20.04.1, 5.15.0.1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1118.128~20.04.1, 5.15.0.1118.128~20.04.1
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1118.128, 5.15.0-1118.128+fips1, 5.15.0.1118.107, 5.15.0.1118.115, 6.8.0-1070.78
linux-azure-fde (Ubuntu package) - addressed in versions 5.15.0-1122.131, 5.15.0.1122.131
linux-gke (Ubuntu package) - addressed in versions 6.8.0-146.146.1~22.04.1, 6.8.0-146.146.1, 6.8.0-1051.55, 6.8.0-1063.66, 6.8.0-1064.67~22.04.1, 6.8.0-1064.67, 6.8.0-1064.67.1, 6.8.0-1065.73, 6.8.0-1066.67
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1068.75~22.04.1, 6.8.0-1068.75, 6.8.0-1069.77+fips1, 6.8.0-1070.78~22.04.1, 6.8.0-1070.78, 7.0.0-1011.11, 7.0.0-1014.14
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

External References

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