CVE-2024-35970: af_unix: Clear stale u->oob_skb.

Q: What is the severity of CVE-2024-35970?

CVE-2024-35970 has been classified as a moderate severity vulnerability in the Linux kernel.

Q: How do I fix CVE-2024-35970?

To fix CVE-2024-35970, upgrade to the patched versions of the Linux kernel: 5.10.223-1, 5.10.226-1, 6.1.119-1, 6.1.123-1, 6.12.11-1, or 6.12.12-1.

Q: Which versions of the Linux kernel are affected by CVE-2024-35970?

CVE-2024-35970 affects the Linux kernel versions prior to the newly released patched versions mentioned in the fix.

Q: What is the nature of the vulnerability identified in CVE-2024-35970?

CVE-2024-35970 is related to a deadlock issue of unix_gc_lock in the af_unix module of the Linux kernel.

Q: Which Linux distributions are impacted by CVE-2024-35970?

CVE-2024-35970 affects Debian-based distributions that use the specified Linux kernel versions.

Published May 20, 2024

Updated

In multiple locations, there is a possible use after free due to a race condition. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.

Other sources

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

afunix: Clear stale u->oobskb.

syzkaller started to report deadlock of unixgclock after commit 4090fa373f0e ("afunix: Replace garbage collection algorithm."), but it just uncovers the bug that has been there since commit 314001f0bf92 ("afunix: Add OOB support").

The repro basically does the following.

from socket import from array import array

c1, c2 = socketpair(AFUNIX, SOCKSTREAM) c1.sendmsg([b'a'], [(SOLSOCKET, SCMRIGHTS, array("i", [c2.fileno()]))], MSGOOB) c2.recv(1) # blocked as no normal data in recv queue

c2.close() # done async and unblock recv() c1.close() # done async and trigger GC

A socket sends its file descriptor to itself as OOB data and tries to receive normal data, but finally recv() fails due to async close().

The problem here is wrong handling of OOB skb in manageoob(). When recvmsg() is called without MSGOOB, manageoob() is called to check if the peeked skb is OOB skb. In such a case, manageoob() pops it out of the receive queue but does not clear unixsock(sk)->oobskb. This is wrong in terms of uAPI.

Let's say we send "hello" with MSGOOB, and "world" without MSGOOB. The 'o' is handled as OOB data. When recv() is called twice without MSGOOB, the OOB data should be lost.

>>> from socket import >>> c1, c2 = socketpair(AFUNIX, SOCKSTREAM, 0) >>> c1.send(b'hello', MSGOOB) # 'o' is OOB data 5 >>> c1.send(b'world') 5 >>> c2.recv(5) # OOB data is not received b'hell' >>> c2.recv(5) # OOB date is skipped b'world' >>> c2.recv(5, MSGOOB) # This should return an error b'o'

In the same situation, TCP actually returns -EINVAL for the last recv().

Also, if we do not clear unixsk(sk)->oobskb, unixpoll() always set EPOLLPRI even though the data has passed through by previous recv().

To avoid these issues, we must clear unixsk(sk)->oobskb when dequeuing it from recv queue.

The reason why the old GC did not trigger the deadlock is because the old GC relied on the receive queue to detect the loop.

When it is triggered, the socket with OOB data is marked as GC candidate because file refcount == inflight count (1). However, after traversing all inflight sockets, the socket still has a positive inflight count (1), thus the socket is excluded from candidates. Then, the old GC lose the chance to garbage-collect the socket.

With the old GC, the repro continues to create true garbage that will never be freed nor detected by kmemleak as it's linked to the global inflight list. That's why we couldn't even notice the issue.

— NVD

Affected Software

145 affected componentsFixes available

Linux Linux kernel>=5.15<5.15.156

Linux Linux kernel>=5.16<6.1.87

Linux Linux kernel>=6.2<6.6.28

Linux Linux kernel>=6.7<6.8.7

Linux Linux kernel=6.9-rc1

Linux Linux kernel=6.9-rc2

Linux Linux kernel=6.9-rc3

Google Android

debian/linux<6.1.90-1

6.1.90-1

debian/linux<6.8.9-1

6.8.9-1

debian/linux<6.8.9-1

6.8.9-1

debian/linux

6.1.176-16.1.190-16.12.107-16.12.115-27.2.12-17.2.15-1

ubuntu/linux-hwe-edge*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-azure*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-5.15<5.15.0-1065.71~20.04.1

5.15.0-1065.71~20.04.1

ubuntu/linux-azure-5.15<5.15.0-1068.77~20.04.1

5.15.0-1068.77~20.04.1

ubuntu/linux-gcp-5.15<5.15.0-1065.73~20.04.1

5.15.0-1065.73~20.04.1

ubuntu/linux-gkeop-5.15<5.15.0-1048.55~20.04.1

5.15.0-1048.55~20.04.1

ubuntu/linux-hwe-5.15<5.15.0-116.126~20.04.1

5.15.0-116.126~20.04.1

ubuntu/linux-ibm-5.15<5.15.0-1058.61~20.04.1

5.15.0-1058.61~20.04.1

ubuntu/linux-intel-iotg-5.15<5.15.0-1060.66~20.04.1

5.15.0-1060.66~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-116.126~20.04.1

5.15.0-116.126~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1027.27~20.04.1

5.15.0-1027.27~20.04.1

ubuntu/linux-oracle-5.15<5.15.0-1063.69~20.04.1

5.15.0-1063.69~20.04.1

ubuntu/linux-riscv-5.15<5.15.0-1061.65~20.04.1

5.15.0-1061.65~20.04.1

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.8*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.8*

ubuntu/linux-intel-5.13*

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.8*

ubuntu/linux<5.15.0-116.126

5.15.0-116.126

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1065.71

5.15.0-1065.71

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1011.12~22.04.1

6.8.0-1011.12~22.04.1

ubuntu/linux-azure<5.15.0-1068.77

5.15.0-1068.77

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1010.10~22.04.1

6.8.0-1010.10~22.04.1

ubuntu/linux-azure-fde<5.15.0-1068.77.1

5.15.0-1068.77.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1064.72

5.15.0-1064.72

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gke<5.15.0-1062.68

5.15.0-1062.68

ubuntu/linux-gkeop<5.15.0-1048.55

5.15.0-1048.55

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-ibm<5.15.0-1058.61

5.15.0-1058.61

ubuntu/linux-intel-iotg<5.15.0-1060.66

5.15.0-1060.66

ubuntu/linux-kvm<5.15.0-1062.67

5.15.0-1062.67

ubuntu/linux-lowlatency<5.15.0-116.126

5.15.0-116.126

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-nvidia<5.15.0-1060.61

5.15.0-1060.61

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1009.9~22.04.1

6.8.0-1009.9~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1026.26

5.15.0-1026.26

ubuntu/linux-nvidia-tegra-igx<5.15.0-1015.15

5.15.0-1015.15

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1063.69

5.15.0-1063.69

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1008.8~22.04.1

6.8.0-1008.8~22.04.1

ubuntu/linux-raspi<5.15.0-1058.61

5.15.0-1058.61

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1035.39

5.15.0-1035.39

ubuntu/linux-bluefield<5.15.0-1047.49

5.15.0-1047.49

ubuntu/linux-intel-iot-realtime<5.15.0-1058.60

5.15.0-1058.60

ubuntu/linux-realtime<5.15.0-1066.74

5.15.0-1066.74

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1065.71+fips1

5.15.0-1065.71+fips1

ubuntu/linux-azure-fips<5.15.0-1068.77+fips1

5.15.0-1068.77+fips1

ubuntu/linux-fips<5.15.0-115.125+fips1

5.15.0-115.125+fips1

ubuntu/linux-gcp-fips<5.15.0-1064.72+fips1

5.15.0-1064.72+fips1

ubuntu/linux<6.8.0-38.38

6.8.0-38.38

ubuntu/linux-aws<6.8.0-1011.12

6.8.0-1011.12

ubuntu/linux-azure<6.8.0-1010.10

6.8.0-1010.10

ubuntu/linux-gcp<6.8.0-1010.11

6.8.0-1010.11

ubuntu/linux-gke<6.8.0-1006.9

6.8.0-1006.9

ubuntu/linux-ibm<6.8.0-1008.8

6.8.0-1008.8

ubuntu/linux-intel<6.8.0-1007.14

6.8.0-1007.14

ubuntu/linux-lowlatency<6.8.0-38.38.1

6.8.0-38.38.1

ubuntu/linux-nvidia<6.8.0-1009.9

6.8.0-1009.9

ubuntu/linux-oem-6.8<6.8.0-1008.8

6.8.0-1008.8

ubuntu/linux-oracle<6.8.0-1008.8

6.8.0-1008.8

ubuntu/linux-raspi<6.8.0-1007.7

6.8.0-1007.7

ubuntu/linux-riscv<6.8.0-38.38.1

6.8.0-38.38.1

ubuntu/linux-raspi-realtime<6.8.0-2006.6

6.8.0-2006.6

ubuntu/linux-realtime<6.8.1-1004.4

6.8.1-1004.4

ubuntu/linux-vmware*

android/:linux_kernel:>=:0<:2025-12-05

:2025-12-05

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.1.90-1
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.8.9-1
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.12-1Fixed in 7.2.15-1
Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1065.71~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1068.77~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1065.73~20.04.1
Upgrade
Upgrade ubuntu/linux-gkeop-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1048.55~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-116.126~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1058.61~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1060.66~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-116.126~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1027.27~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1063.69~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1061.65~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-116.126
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1065.71
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1011.12~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1068.77
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1010.10~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1068.77.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1064.72
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1062.68
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1048.55
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1058.61
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1060.66
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1062.67
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-116.126
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1060.61
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1009.9~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1026.26
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1015.15
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1063.69
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1008.8~22.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1058.61
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1035.39
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1047.49
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1058.60
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1066.74
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1065.71+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1068.77+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-115.125+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1064.72+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-38.38
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1011.12
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1010.10
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1010.11
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1006.9
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1008.8
Upgrade
Upgrade ubuntu/linux-intel to a version that resolves this vulnerability.
Fixed in 6.8.0-1007.14
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-38.38.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1009.9
Upgrade
Upgrade ubuntu/linux-oem-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1008.8
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1008.8
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.8.0-1007.7
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 6.8.0-38.38.1
Upgrade
Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.
Fixed in 6.8.0-2006.6
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1004.4
Upgrade
Upgrade android/:linux_kernel: to a version that resolves this vulnerability.
Fixed in :2025-12-05

Event History

May 20, 2024

CVE Published

via MITRE·09:41 AM

Data Sourced

via MITRE·09:41 AM

Description

Data Sourced

via OSV·10:15 AM

DescriptionSeverityAffected Software

Dec 1, 2025

Advisory Published

via OSV·12:00 AM

Data Sourced

via Android·12:00 AM

SeverityWeaknessAffected Software

Frequently Asked Questions

What is the severity of CVE-2024-35970?

CVE-2024-35970 has been classified as a moderate severity vulnerability in the Linux kernel.

How do I fix CVE-2024-35970?

To fix CVE-2024-35970, upgrade to the patched versions of the Linux kernel: 5.10.223-1, 5.10.226-1, 6.1.119-1, 6.1.123-1, 6.12.11-1, or 6.12.12-1.

Which versions of the Linux kernel are affected by CVE-2024-35970?

CVE-2024-35970 affects the Linux kernel versions prior to the newly released patched versions mentioned in the fix.

What is the nature of the vulnerability identified in CVE-2024-35970?

CVE-2024-35970 is related to a deadlock issue of unix_gc_lock in the af_unix module of the Linux kernel.

Which Linux distributions are impacted by CVE-2024-35970?

CVE-2024-35970 affects Debian-based distributions that use the specified Linux kernel versions.

CVE-2024-35970: af_unix: Clear stale u->oob_skb.

Other sources

Affected Software

Remediation

Event History

Frequently Asked Questions

What is the severity of CVE-2024-35970?

How do I fix CVE-2024-35970?

Which versions of the Linux kernel are affected by CVE-2024-35970?

What is the nature of the vulnerability identified in CVE-2024-35970?

Which Linux distributions are impacted by CVE-2024-35970?

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