CVE-2025-21812: ax25: rcu protect dev->ax25_ptr

Q: What is the severity of CVE-2025-21812?

CVE-2025-21812 is classified as a medium severity vulnerability in the Linux kernel.

Q: What does CVE-2025-21812 affect?

CVE-2025-21812 affects the Linux kernel and specifically relates to the ax25 TCP/IP stack module.

Q: How do I fix CVE-2025-21812?

To fix CVE-2025-21812, update the Linux kernel to the latest stable version where the vulnerability has been patched.

Q: What are the potential impacts of CVE-2025-21812?

The potential impacts of CVE-2025-21812 include user-after-free vulnerabilities and possible denial of service due to the lockdep issue.

Q: When was CVE-2025-21812 disclosed?

CVE-2025-21812 was disclosed as part of ongoing security updates for the Linux kernel.

Published Feb 27, 2025

Updated

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

ax25: rcu protect dev->ax25ptr

syzbot found a lockdep issue [1].

We should remove ax25 RTNL dependency in ax25setsockopt()

This should also fix a variety of possible UAF in ax25.

[1]

WARNING: possible circular locking dependency detected 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Not tainted ------------------------------------------------------ syz.5.1818/12806 is trying to acquire lock: ffffffff8fcb3988 (rtnlmutex){+.+.}-{4:4}, at: ax25setsockopt+0xa55/0xe90 net/ax25/afax25.c:680

but task is already holding lock: ffff8880617ac258 (sklock-AFAX25){+.+.}-{0:0}, at: locksock include/net/sock.h:1618 [inline] ffff8880617ac258 (sklock-AFAX25){+.+.}-{0:0}, at: ax25setsockopt+0x209/0xe90 net/ax25/afax25.c:574

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (sklock-AFAX25){+.+.}-{0:0}: lockacquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 locksocknested+0x48/0x100 net/core/sock.c:3642 locksock include/net/sock.h:1618 [inline] ax25killbydevice net/ax25/afax25.c:101 [inline] ax25deviceevent+0x24d/0x580 net/ax25/afax25.c:146 notifiercallchain+0x1a5/0x3f0 kernel/notifier.c:85 devnotifyflags+0x207/0x400 devchangeflags+0xf0/0x1a0 net/core/dev.c:9026 devifsioc+0x7c8/0xe70 net/core/devioctl.c:563 devioctl+0x719/0x1340 net/core/devioctl.c:820 sockdoioctl+0x240/0x460 net/socket.c:1234 sockioctl+0x626/0x8e0 net/socket.c:1339 vfsioctl fs/ioctl.c:51 [inline] dosysioctl fs/ioctl.c:906 [inline] sesysioctl+0xf5/0x170 fs/ioctl.c:892 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xf3/0x230 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x77/0x7f

-> #0 (rtnlmutex){+.+.}-{4:4}: checkprevadd kernel/locking/lockdep.c:3161 [inline] checkprevsadd kernel/locking/lockdep.c:3280 [inline] validatechain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 lockacquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lockacquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 mutexlockcommon kernel/locking/mutex.c:585 [inline] mutexlock+0x1ac/0xee0 kernel/locking/mutex.c:735 ax25setsockopt+0xa55/0xe90 net/ax25/afax25.c:680 dosocksetsockopt+0x3af/0x720 net/socket.c:2324 syssetsockopt net/socket.c:2349 [inline] dosyssetsockopt net/socket.c:2355 [inline] sesyssetsockopt net/socket.c:2352 [inline] x64syssetsockopt+0x1ee/0x280 net/socket.c:2352 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xf3/0x230 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x77/0x7f

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1 ---- ---- lock(sklock-AFAX25); lock(rtnlmutex); lock(sklock-AFAX25); lock(rtnlmutex);

DEADLOCK

1 lock held by syz.5.1818/12806: #0: ffff8880617ac258 (sklock-AFAX25){+.+.}-{0:0}, at: locksock include/net/sock.h:1618 [inline] #0: ffff8880617ac258 (sklock-AFAX25){+.+.}-{0:0}, at: ax25setsockopt+0x209/0xe90 net/ax25/afax25.c:574

stack backtrace: CPU: 1 UID: 0 PID: 12806 Comm: syz.5.1818 Not tainted 6.13.0-rc3-syzkaller-00762-g9268abe611b0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> dumpstack lib/dumpstack.c:94 [inline] dumpstacklvl+0x241/0x360 lib/dumpstack.c:120 printcircularbug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 checknoncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2206 checkprevadd kernel/locking/lockdep.c:3161 [inline] checkprevsadd kernel/lockin ---truncated---

Affected Software

214 affected componentsFixes available

Linux Linux kernel

Linux Linux kernel>=3.18.132<3.19

Linux Linux kernel>=4.4.170<4.5

Linux Linux kernel>=4.9.149<4.10

Linux Linux kernel>=4.14.92<4.15

Linux Linux kernel>=4.19.14<4.20

Linux Linux kernel>=4.20.1<6.1.129

Linux Linux kernel>=6.2<6.6.76

Linux Linux kernel>=6.7<6.12.13

Linux Linux kernel>=6.13<6.13.2

ubuntu/linux-aws*

ubuntu/linux-azure*

ubuntu/linux-lts-xenial*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-hwe*

ubuntu/linux-azure*

ubuntu/linux-gcp*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-kvm*

ubuntu/linux-oracle*

ubuntu/linux-fips*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-aws-5.4*

ubuntu/linux-azure*

ubuntu/linux-azure-4.15*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-5.4*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-4.15*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gcp-5.4*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-5.4*

ubuntu/linux-hwe-edge*

ubuntu/linux-ibm-5.4*

ubuntu/linux-kvm*

ubuntu/linux-oem*

ubuntu/linux-oracle*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-oracle-5.4*

ubuntu/linux-raspi-5.4*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-fips*

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.15<5.15.0-1119.126~20.04.1

5.15.0-1119.126~20.04.1

ubuntu/linux-aws-5.8*

ubuntu/linux-azure*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.15<5.15.0-1125.134~20.04.1

5.15.0-1125.134~20.04.1

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-azure-fde-5.15<5.15.0-1124.133~20.04.1

5.15.0-1124.133~20.04.1

ubuntu/linux-bluefield*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.15<5.15.0-1120.130~20.04.1

5.15.0-1120.130~20.04.1

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.15<5.15.0-202.212~20.04.1

5.15.0-202.212~20.04.1

ubuntu/linux-hwe-5.8*

ubuntu/linux-ibm*

ubuntu/linux-ibm-5.15<5.15.0-1113.117~20.04.1

5.15.0-1113.117~20.04.1

ubuntu/linux-intel-5.13*

ubuntu/linux-intel-iotg-5.15<5.15.0-1114.120~20.04.1

5.15.0-1114.120~20.04.1

ubuntu/linux-iot*

ubuntu/linux-kvm*

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-197.207~20.04.1

5.15.0-197.207~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1070.72~20.04.1

5.15.0-1070.72~20.04.1

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.15<5.15.0-1116.122~20.04.1

5.15.0-1116.122~20.04.1

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.15<5.15.0-1113.117~20.04.2

5.15.0-1113.117~20.04.2

ubuntu/linux-riscv-5.8*

ubuntu/linux-xilinx-zynqmp*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux*

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1119.126

5.15.0-1119.126

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1032.34~22.04.1

6.8.0-1032.34~22.04.1

ubuntu/linux-azure<5.15.0-1125.134

5.15.0-1125.134

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1034.39~22.04.1

6.8.0-1034.39~22.04.1

ubuntu/linux-azure-fde<5.15.0-1124.133

5.15.0-1124.133

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1120.130

5.15.0-1120.130

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1033.35~22.04.1

6.8.0-1033.35~22.04.1

ubuntu/linux-gke<5.15.0-1115.121

5.15.0-1115.121

ubuntu/linux-gkeop<5.15.0-1102.110

5.15.0-1102.110

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-64.67~22.04.1

6.8.0-64.67~22.04.1

ubuntu/linux-ibm<5.15.0-1113.117

5.15.0-1113.117

ubuntu/linux-ibm-6.8<6.8.0-1029.29~22.04.1

6.8.0-1029.29~22.04.1

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-intel-iotg<5.15.0-1114.120

5.15.0-1114.120

ubuntu/linux-kvm<5.15.0-1111.116

5.15.0-1111.116

ubuntu/linux-lowlatency<5.15.0-197.207

5.15.0-197.207

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-64.67.1~22.04.1

6.8.0-64.67.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1114.115

5.15.0-1114.115

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1031.34~22.04.1

6.8.0-1031.34~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1070.72

5.15.0-1070.72

ubuntu/linux-nvidia-tegra-igx<5.15.0-1059.59

5.15.0-1059.59

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1116.122

5.15.0-1116.122

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1029.30~22.04.1

6.8.0-1029.30~22.04.1

ubuntu/linux-raspi*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-64.67~22.04.1

6.8.0-64.67~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp*

ubuntu/linux-bluefield<5.15.0-1103.105

5.15.0-1103.105

ubuntu/linux-intel-iot-realtime<5.15.0-1111.115

5.15.0-1111.115

ubuntu/linux-realtime<5.15.0-1118.127

5.15.0-1118.127

ubuntu/linux-realtime-6.8<6.8.1-1025.26~22.04.1

6.8.1-1025.26~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1119.126+fips1

5.15.0-1119.126+fips1

ubuntu/linux-azure-fips<5.15.0-1125.134+fips1

5.15.0-1125.134+fips1

ubuntu/linux-fips<5.15.0-202.212+fips1

5.15.0-202.212+fips1

ubuntu/linux-gcp-fips<5.15.0-1120.130+fips1

5.15.0-1120.130+fips1

ubuntu/linux<6.8.0-64.67

6.8.0-64.67

ubuntu/linux-aws<6.8.0-1032.34

6.8.0-1032.34

ubuntu/linux-azure<6.8.0-1034.39

6.8.0-1034.39

ubuntu/linux-azure-6.11<6.11.0-1015.15~24.04.1

6.11.0-1015.15~24.04.1

ubuntu/linux-azure-nvidia<6.8.0-1022.23

6.8.0-1022.23

ubuntu/linux-gcp<6.8.0-1033.35

6.8.0-1033.35

ubuntu/linux-gcp-6.11<6.11.0-1015.15~24.04.1

6.11.0-1015.15~24.04.1

ubuntu/linux-gke<6.8.0-1028.32

6.8.0-1028.32

ubuntu/linux-gkeop<6.8.0-1015.17

6.8.0-1015.17

ubuntu/linux-hwe-6.11<6.11.0-26.26~24.04.1

6.11.0-26.26~24.04.1

ubuntu/linux-ibm<6.8.0-1029.29

6.8.0-1029.29

ubuntu/linux-lowlatency<6.8.0-64.67.1

6.8.0-64.67.1

ubuntu/linux-lowlatency-hwe-6.11<6.11.0-1014.15~24.04.1

6.11.0-1014.15~24.04.1

ubuntu/linux-nvidia<6.8.0-1031.34

6.8.0-1031.34

ubuntu/linux-nvidia-6.11<6.11.0-1010.10

6.11.0-1010.10

ubuntu/linux-nvidia-lowlatency<6.8.0-1031.34.1

6.8.0-1031.34.1

ubuntu/linux-nvidia-tegra<6.8.0-1008.8

6.8.0-1008.8

ubuntu/linux-oem-6.11<6.11.0-1022.22

6.11.0-1022.22

ubuntu/linux-oem-6.8<6.8.0-1031.31

6.8.0-1031.31

ubuntu/linux-oracle<6.8.0-1029.30

6.8.0-1029.30

ubuntu/linux-raspi<6.8.0-1031.35

6.8.0-1031.35

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-xilinx<6.8.0-1017.18

6.8.0-1017.18

ubuntu/linux-raspi-realtime<6.8.0-2026.27

6.8.0-2026.27

ubuntu/linux-realtime<6.8.1-1025.26

6.8.1-1025.26

ubuntu/linux-fips<6.8.0-78.78+fips1

6.8.0-78.78+fips1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1119.126~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1125.134~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1124.133~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1120.130~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-202.212~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1113.117~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.120~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-197.207~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1070.72~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1116.122~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1113.117~20.04.2
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1119.126
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1032.34~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1125.134
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1034.39~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1124.133
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1120.130
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1033.35~22.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1115.121
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1102.110
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-64.67~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1113.117
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1029.29~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.120
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1111.116
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-197.207
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-64.67.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1114.115
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1031.34~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1070.72
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1059.59
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1116.122
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1029.30~22.04.1
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-64.67~22.04.1
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1103.105
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1111.115
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1118.127
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1025.26~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1119.126+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1125.134+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-202.212+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1120.130+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-64.67
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1032.34
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1034.39
Upgrade
Upgrade ubuntu/linux-azure-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1015.15~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1022.23
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1033.35
Upgrade
Upgrade ubuntu/linux-gcp-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1015.15~24.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.32
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1015.17
Upgrade
Upgrade ubuntu/linux-hwe-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-26.26~24.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1029.29
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-64.67.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1014.15~24.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1031.34
Upgrade
Upgrade ubuntu/linux-nvidia-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1010.10
Upgrade
Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-1031.34.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 6.8.0-1008.8
Upgrade
Upgrade ubuntu/linux-oem-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1022.22
Upgrade
Upgrade ubuntu/linux-oem-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1031.31
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1029.30
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.8.0-1031.35
Upgrade
Upgrade ubuntu/linux-xilinx to a version that resolves this vulnerability.
Fixed in 6.8.0-1017.18
Upgrade
Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.
Fixed in 6.8.0-2026.27
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1025.26
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78+fips1

Event History

Feb 27, 2025

CVE Published

via MITRE·08:01 PM

Data Sourced

via MITRE·08:01 PM

DescriptionSeverity

Data Sourced

via OSV·08:16 PM

DescriptionSeverityAffected Software

Data Sourced

via NVD·08:16 PM

RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

What is the severity of CVE-2025-21812?

CVE-2025-21812 is classified as a medium severity vulnerability in the Linux kernel.

What does CVE-2025-21812 affect?

CVE-2025-21812 affects the Linux kernel and specifically relates to the ax25 TCP/IP stack module.

How do I fix CVE-2025-21812?

To fix CVE-2025-21812, update the Linux kernel to the latest stable version where the vulnerability has been patched.

What are the potential impacts of CVE-2025-21812?

The potential impacts of CVE-2025-21812 include user-after-free vulnerabilities and possible denial of service due to the lockdep issue.

When was CVE-2025-21812 disclosed?

CVE-2025-21812 was disclosed as part of ongoing security updates for the Linux kernel.

CVE-2025-21812: ax25: rcu protect dev->ax25_ptr

Affected Software

Remediation

Event History

Frequently Asked Questions

What is the severity of CVE-2025-21812?

What does CVE-2025-21812 affect?

How do I fix CVE-2025-21812?

What are the potential impacts of CVE-2025-21812?

When was CVE-2025-21812 disclosed?

Company

Resources

Contact