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Unscored CVE-2025-21820 EUVD-2025-5974GHSA-pgjm-rqqp-m93m

tty: xilinx_uartps: split sysrq handling

Published Feb 27, 2025 · Updated May 11, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-aws-hwe Package: linux-azure Package: linux-azure-4.15 Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.2 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-4.15 Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-5.4 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

tty: xilinx_uartps: split sysrq handling

lockdep detects the following circular locking dependency:

CPU 0 CPU 1
========================== ============================
cdns_uart_isr() printk()
uart_port_lock(port) console_lock()
cdns_uart_console_write()
if (!port->sysrq)
uart_port_lock(port)
uart_handle_break()
port->sysrq = ...
uart_handle_sysrq_char()
printk()
console_lock()

The fixed commit attempts to avoid this situation by only taking the
port lock in cdns_uart_console_write if port->sysrq unset. However, if
(as shown above) cdns_uart_console_write runs before port->sysrq is set,
then it will try to take the port lock anyway. This may result in a
deadlock.

Fix this by splitting sysrq handling into two parts. We use the prepare
helper under the port lock and defer handling until we release the lock.

Affected products

VendorProductAffectedFixed
Linux Linux 4.6 5.15.179

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.12.15-1 —
Debian 13 linux 6.12.15-1 —
Debian 12 linux 6.1.129-1 —
Debian 11 linux-6.1 6.1.129-1~deb11u1 DLA-4102-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1066.68 —
Ubuntu 24.04 LTS linux 6.8.0-64.67 USN-7651-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1032.34 USN-7651-1
Ubuntu 24.04 LTS linux-azure 6.8.0-1034.39 USN-7737-1
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1022.23 USN-7737-1
Ubuntu 24.04 LTS linux-gcp 6.8.0-1033.35 USN-7651-4
Ubuntu 24.04 LTS linux-gcp-6.11 +1 6.11.0-1015.15~24.04.1 USN-7521-1
Ubuntu 24.04 LTS linux-gke 6.8.0-1028.32 USN-7651-3
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1015.17 USN-7651-3
Ubuntu 24.04 LTS linux-hwe-6.11 6.11.0-26.26~24.04.1 USN-7521-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1029.29 USN-7651-2
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-64.67.1 USN-7651-2
Ubuntu 24.04 LTS linux-lowlatency-hwe-6.11 6.11.0-1014.15~24.04.1 USN-7521-3
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1031.34 USN-7651-3
Ubuntu 24.04 LTS linux-nvidia-6.11 6.11.0-1010.10 —
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1031.34.1 USN-7651-3
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1008.8 —
Ubuntu 24.04 LTS linux-oem-6.11 6.11.0-1022.22 USN-7521-1
Ubuntu 24.04 LTS linux-oem-6.8 6.8.0-1031.31 USN-7651-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1029.30 USN-7651-3
Ubuntu 24.04 LTS linux-raspi 6.8.0-1031.35 USN-7651-6
Ubuntu 24.04 LTS linux-riscv +2 No fix yet —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1017.18 —
Ubuntu 22.04 LTS linux +1 5.15.0-140.150 USN-7510-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1084.91 USN-7510-7
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1032.34~22.04.1 USN-7651-3
Ubuntu 22.04 LTS linux-azure 5.15.0-1089.98 USN-7510-3
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1034.39~22.04.1 USN-7737-1
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1089.98.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1083.92 USN-7511-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1033.35~22.04.1 USN-7651-4
Ubuntu 22.04 LTS linux-gke +1 5.15.0-1081.87 USN-7511-3, USN-7510-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1066.74 USN-7510-1
Ubuntu 22.04 LTS linux-hwe-6.8 +1 6.8.0-64.67~22.04.1 USN-7653-1
Ubuntu 22.04 LTS linux-ibm 5.15.0-1076.79 USN-7510-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1029.29~22.04.1 USN-7651-2
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1079.85 USN-7510-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1080.85 USN-7510-1
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-64.67.1~22.04.1 USN-7651-2
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1078.79 USN-7510-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1031.34~22.04.1 USN-7651-3
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1037.37 USN-7510-3
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1026.26 USN-7510-7
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1029.30~22.04.1 USN-7651-3
Ubuntu 22.04 LTS linux-raspi 5.15.0-1078.81 USN-7510-7
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1050.54 USN-7602-1
Ubuntu 20.04 LTS linux-aws-5.15 5.15.0-1084.91~20.04.1 USN-7510-8
Ubuntu 20.04 LTS linux-azure-5.15 5.15.0-1089.98~20.04.1 USN-7510-3
Ubuntu 20.04 LTS linux-gcp-5.15 5.15.0-1083.92~20.04.1 USN-7512-1
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 20.04 LTS linux-ibm-5.15 5.15.0-1076.79~20.04.1 USN-7510-1
Ubuntu 20.04 LTS linux-intel-iotg-5.15 5.15.0-1079.85~20.04.1 USN-7510-7
Ubuntu 20.04 LTS linux-lowlatency-hwe-5.15 5.15.0-140.150~20.04.1 USN-7510-1
Ubuntu 20.04 LTS linux-oracle-5.15 5.15.0-1081.87~20.04.1 USN-7510-1
Ubuntu 20.04 LTS linux-riscv-5.15 5.15.0-1079.83~20.04.1 —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Show 14 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2026.27 USN-7651-5
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1025.26 USN-7652-1
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1077.79 USN-7510-4
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1084.93 USN-7510-4
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1025.26~22.04.1 —
Ubuntu Pro FIPS 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-78.78+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1084.91+fips1 USN-7510-6
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1089.98+fips1 USN-7510-5
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-140.150+fips1 USN-7510-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1083.92+fips1 USN-7511-2
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-preview 22.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro 20.04 LTS linux +10 No fix yet —
Ubuntu Pro 20.04 LTS linux-hwe-5.15 5.15.0-142.152~20.04.1 USN-7593-1
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1039.39~20.04.1 —
Ubuntu Pro 18.04 LTS linux +12 No fix yet —
Ubuntu Pro 16.04 LTS linux-gcp +4 No fix yet —
Ubuntu Pro 14.04 LTS linux-azure No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP6 kernel-64kb +3 6.4.0-150600.23.47.2 SUSE-SU-2025:1180-1
SLES 15 SP6 kernel-azure +1 6.4.0-150600.8.34.2 SUSE-SU-2025:1177-1
SLES 15 SP6 kernel-coco +3 6.4.0-15061.21.coco15sp6.1 SUSE-SU-2025:01919-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.47.2.150600.12.20.2 SUSE-SU-2025:1180-1
SLES 15 SP6 kernel-docs +2 6.4.0-150600.23.47.1 SUSE-SU-2025:1180-1
SLES 15 SP6 kernel-syms-azure 6.4.0-150600.8.34.1 SUSE-SU-2025:1177-1
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLE Micro 6.1 kernel-default-base 6.4.0-28.1.21.6 SUSE-SU-2025:20270-1
SLE Micro 6.1 kernel-livepatch-MICRO-6-0_Update_6 +1 1-3.1 SUSE-SU-2025:20270-1, SUSE-SU-2025:20260-1
SLE Micro 6.1 kernel-rt +4 6.4.0-28.1 SUSE-SU-2025:20270-1, SUSE-SU-2025:20260-1
SLE Micro 6.0 kernel-default-base 6.4.0-28.1.21.6 SUSE-SU-2025:20192-1
SLE Micro 6.0 kernel-livepatch-MICRO-6-0_Update_6 +1 1-3.1 SUSE-SU-2025:20192-1, SUSE-SU-2025:20190-1
SLE Micro 6.0 kernel-rt +4 6.4.0-28.1 SUSE-SU-2025:20192-1, SUSE-SU-2025:20190-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.47.2 SUSE-SU-2025:1180-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_10 1-150600.1.5.1 SUSE-SU-2025:1178-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_10 1-150600.13.5.1 SUSE-SU-2025:1180-1
SUSE Real Time Module 15 SP6 kernel-rt +3 6.4.0-150600.10.34.1 SUSE-SU-2025:1178-1
ReleasePackageFixed inAdvisory
openSUSE Leap 15.6 dtb-aarch64 +4 6.4.0-150600.23.47.1 SUSE-SU-2025:1180-1
openSUSE Leap 15.6 kernel-64kb +5 6.4.0-150600.23.47.2 SUSE-SU-2025:1180-1
openSUSE Leap 15.6 kernel-azure +1 6.4.0-150600.8.34.2 SUSE-SU-2025:1177-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.47.2.150600.12.20.2 SUSE-SU-2025:1180-1
openSUSE Leap 15.6 kernel-rt +3 6.4.0-150600.10.34.1 SUSE-SU-2025:1178-1
openSUSE Leap 15.6 kernel-syms-azure 6.4.0-150600.8.34.1 SUSE-SU-2025:1177-1

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 2 (CBL-Mariner) kernel 5.15.179.1-1 —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 kernel-uek +34 6.12.0-101.33.4.3.el10uek ELSA-2025-20530, ELSA-2025-20480

Advisories 38

References