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Unscored CVE-2025-68335 EUVD-2025-204728GHSA-7r9r-9pcc-36g7

comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel()

Published Dec 22, 2025 · Updated May 11, 2026 · Assigned by Linux

Vendor: Linux Product: Linux 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-6.14 Package: linux-aws-6.17 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-6.14 Package: linux-azure-6.17 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-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 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-6.14 Package: linux-gcp-6.17 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-6.14 Package: linux-hwe-6.17 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-lts-xenial Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 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-6.14 Package: linux-oem-6.17 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-6.14 Package: linux-oracle-6.17 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-6.14 Package: linux-realtime-6.17 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-6.14 Package: linux-riscv-6.17 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: Debian Ecosystem: Ubuntu

Description

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

comedi: pcl818: fix null-ptr-deref in pcl818_ai_cancel()

Syzbot identified an issue [1] in pcl818_ai_cancel(), which stems from
the fact that in case of early device detach via pcl818_detach(),
subdevice dev->read_subdev may not have initialized its pointer to
&struct comedi_async as intended. Thus, any such dereferencing of
&s->async->cmd will lead to general protection fault and kernel crash.

Mitigate this problem by removing a call to pcl818_ai_cancel() from
pcl818_detach() altogether. This way, if the subdevice setups its
support for async commands, everything async-related will be
handled via subdevice's own ->cancel() function in
comedi_device_detach_locked() even before pcl818_detach(). If no
support for asynchronous commands is provided, there is no need
to cancel anything either.

[1] Syzbot crash:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 1 UID: 0 PID: 6050 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:pcl818_ai_cancel+0x69/0x3f0 drivers/comedi/drivers/pcl818.c:762
...
Call Trace:
<TASK>
pcl818_detach+0x66/0xd0 drivers/comedi/drivers/pcl818.c:1115
comedi_device_detach_locked+0x178/0x750 drivers/comedi/drivers.c:207
do_devconfig_ioctl drivers/comedi/comedi_fops.c:848 [inline]
comedi_unlocked_ioctl+0xcde/0x1020 drivers/comedi/comedi_fops.c:2178
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
...

Affected products

VendorProductAffectedFixed
Linux Linux 3.15 5.15.198

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 6.17.12-1 —
Debian 13 linux 6.12.63-1 —
Debian 12 linux 6.1.162-1 DSA-6127-1
Debian 11 linux-6.1 6.1.162-1~deb11u1 DLA-4476-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1017.21 —
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1086.88 —
Ubuntu 25.10 linux 6.17.0-19.19 USN-8094-1
Ubuntu 25.10 linux-aws +2 6.17.0-1009.9 USN-8094-1
Ubuntu 25.10 linux-azure +1 6.17.0-1010.10 USN-8094-5, USN-8094-4
Ubuntu 25.10 linux-azure-fde No fix yet —
Ubuntu 25.10 linux-realtime 6.17.0-1008.9 USN-8094-2
Ubuntu 25.10 linux-riscv 6.17.0-19.19.1 —
Ubuntu 24.04 LTS linux 6.8.0-110.110 USN-8179-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1052.55 USN-8179-1
Ubuntu 24.04 LTS linux-aws-6.17 6.17.0-1009.9~24.04.2 USN-8094-1
Ubuntu 24.04 LTS linux-azure 6.8.0-1054.60 USN-8258-1
Ubuntu 24.04 LTS linux-azure-6.17 6.17.0-1010.10~24.04.1 USN-8094-4
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1058.65 —
Ubuntu 24.04 LTS linux-azure-nvidia 6.8.0-1039.42 —
Ubuntu 24.04 LTS linux-gcp 6.8.0-1054.57 USN-8179-1
Ubuntu 24.04 LTS linux-gcp-6.17 6.17.0-1009.9~24.04.3 USN-8094-2
Ubuntu 24.04 LTS linux-gke 6.8.0-1050.56 USN-8179-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1037.40 USN-8179-1
Ubuntu 24.04 LTS linux-hwe-6.17 6.17.0-19.19~24.04.2 USN-8094-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1051.51 USN-8179-1
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-110.110.1 USN-8179-1
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1051.54 USN-8185-1
Ubuntu 24.04 LTS linux-nvidia-6.17 6.17.0-1018.18 —
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1051.54.1 USN-8185-2
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1022.22 USN-8265-1
Ubuntu 24.04 LTS linux-oem-6.17 6.17.0-1017.17 USN-8152-1
Ubuntu 24.04 LTS linux-oracle 6.8.0-1049.50 USN-8203-1
Ubuntu 24.04 LTS linux-oracle-6.17 6.17.0-1009.9~24.04.1 USN-8094-1
Ubuntu 24.04 LTS linux-raspi 6.8.0-1052.56 USN-8179-3
Ubuntu 24.04 LTS linux-riscv +18 No fix yet —
Ubuntu 24.04 LTS linux-riscv-6.17 6.17.0-19.19.1~24.04.1 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1028.29 USN-8261-1
Ubuntu 22.04 LTS linux +1 5.15.0-173.183 USN-8096-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1103.110 USN-8096-1
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1052.55~22.04.1 USN-8179-1
Ubuntu 22.04 LTS linux-azure 5.15.0-1109.118 USN-8163-2
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1059.65~22.04.1 USN-8440-1
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1109.118.1 —
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1058.65~22.04.1 —
Ubuntu 22.04 LTS linux-gcp 5.15.0-1103.112 USN-8096-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1054.57~22.04.1 USN-8179-4
Ubuntu 22.04 LTS linux-gke 5.15.0-1099.105 USN-8096-3
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1086.94 USN-8096-1
Ubuntu 22.04 LTS linux-hwe-6.8 +1 6.8.0-110.110~22.04.1 USN-8179-3
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1097.100 USN-8141-1, USN-8096-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1051.51~22.04.1 USN-8179-3
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1098.104 USN-8096-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1095.100 USN-8096-1
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-110.110.1~22.04.1 USN-8179-1
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1098.99 USN-8096-1
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1051.54~22.04.1 USN-8185-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1055.55 USN-8096-1
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1044.44 USN-8096-5
Ubuntu 22.04 LTS linux-oracle 5.15.0-1100.106 USN-8096-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1049.50~22.04.1 USN-8203-1
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1067.71 USN-8096-1
Show 18 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2042.43 USN-8204-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1047.48 USN-8184-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.17 6.17.0-1008.9~24.04.1 USN-8094-3
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1094.96 USN-8116-1
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1102.111 USN-8096-4
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1047.48~22.04.1 USN-8184-1
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 16.04 LTS linux-fips No fix yet —
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1052.55+fips1 USN-8179-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1053.59+fips1 —
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-110.110+fips2 USN-8179-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1054.57+fips1 USN-8179-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1103.110+fips1 USN-8096-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1109.118+fips1 USN-8163-1
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-173.183+fips1 USN-8096-2
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1103.112+fips1 USN-8096-2
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-updates 16.04 LTS linux-fips 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-aws-5.15 5.15.0-1103.110~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-azure-5.15 5.15.0-1110.119~20.04.1 USN-8243-1
Ubuntu Pro 20.04 LTS linux-gcp-5.15 5.15.0-1103.112~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-hwe-5.15 +1 5.15.0-173.183~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-ibm-5.15 5.15.0-1097.100~20.04.1 USN-8096-1
Ubuntu Pro 20.04 LTS linux-intel-iotg-5.15 5.15.0-1098.104~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1055.55~20.04.1 USN-8096-1
Ubuntu Pro 20.04 LTS linux-oracle-5.15 5.15.0-1100.106~20.04.1 USN-8096-3
Ubuntu Pro 20.04 LTS linux-riscv-5.15 5.15.0-1097.101~20.04.1 —
Ubuntu Pro 18.04 LTS linux +12 No fix yet —
Ubuntu Pro 16.04 LTS linux +7 No fix yet —
Ubuntu Pro 14.04 LTS linux-aws +2 No fix yet —
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +6 6.4.0-150700.53.28.1 SUSE-SU-2026:0315-1
SLES 15 SP7 kernel-azure +2 6.4.0-150700.20.24.1 SUSE-SU-2026:0281-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.28.1.150700.17.19.1 SUSE-SU-2026:0315-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.84.1 SUSE-SU-2026:0293-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.84.1.150600.12.38.1 SUSE-SU-2026:0293-1
Show 9 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 kernel-64kb +8 6.12.0-160000.9.1 SUSE-SU-2026:20220-1
SLES for SAP 16.0 kernel-default-base 6.12.0-160000.9.1.160000.2.6 SUSE-SU-2026:20220-1
SLES for SAP 15 SP6 kernel-default-base 6.4.0-150600.23.84.1.150600.12.38.1 SUSE-SU-2026:0293-1
SLES for SAP 15 SP6 kernel-docs +4 6.4.0-150600.23.84.1 SUSE-SU-2026:0293-1
SLES 16.0 kernel-64kb +8 6.12.0-160000.9.1 SUSE-SU-2026:20228-1, SUSE-SU-2026:20220-1
SLES 16.0 kernel-default-base 6.12.0-160000.9.1.160000.2.6 SUSE-SU-2026:20220-1
SLE Micro 6.2 kernel-default-base 6.12.0-160000.9.1.160000.2.6 SUSE-SU-2026:20207-1
SLE Micro 6.2 kernel-rt +5 6.12.0-160000.9.1 SUSE-SU-2026:20564-1, SUSE-SU-2026:20207-1
SLE Micro 6.1 kernel-default-base 6.4.0-39.1.21.16 SUSE-SU-2026:20498-1
SLE Micro 6.1 kernel-rt +1 6.4.0-40.1 SUSE-SU-2026:20876-1
SLE Micro 6.1 kernel-source +2 6.4.0-39.1 SUSE-SU-2026:20498-1
SLE Micro 6.0 kernel-default-base 6.4.0-39.1.21.16 SUSE-SU-2026:20477-1
SLE Micro 6.0 kernel-rt +1 6.4.0-40.1 SUSE-SU-2026:20845-1
SLE Micro 6.0 kernel-source +2 6.4.0-39.1 SUSE-SU-2026:20477-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.28.1 SUSE-SU-2026:0315-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_8 1-150700.1.3.1 SUSE-SU-2026:0278-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_8 1-150700.15.3.1 SUSE-SU-2026:0315-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.84.1 SUSE-SU-2026:0293-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_19 1-150600.13.3.1 SUSE-SU-2026:0293-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.28.1 SUSE-SU-2026:0278-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed kernel-source 6.18.5-1.1 openSUSE-SU-2026:10039-1
openSUSE Tumbleweed kernel-source-longterm 6.18.16-1.1 openSUSE-SU-2026:10301-1
openSUSE Leap 16.0 kernel-default-base 6.12.0-160000.9.1.160000.2.6 openSUSE-SU-2026:20145-1
openSUSE Leap 16.0 kernel-rt +11 6.12.0-160000.9.1 openSUSE-SU-2026:20145-1
openSUSE Leap 15.6 dtb-aarch64 +10 6.4.0-150600.23.84.1 SUSE-SU-2026:0293-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.84.1.150600.12.38.1 SUSE-SU-2026:0293-1

Advisories 47

References