CVE-2021-47162: tipc: skb_linearize the head skb when reassembling msgs

Q: What is the severity of CVE-2021-47162?

CVE-2021-47162 has been categorized as having a moderate severity level.

Q: How do I fix CVE-2021-47162?

To fix CVE-2021-47162, you should update to the latest stable version of the Linux kernel that includes the patch.

Q: What systems are affected by CVE-2021-47162?

CVE-2021-47162 affects various versions of the Linux kernel that are vulnerable to the described issue.

Q: What is the nature of the vulnerability in CVE-2021-47162?

The vulnerability in CVE-2021-47162 involves improper handling of the skb's frag_list during message reassembly.

Q: Is CVE-2021-47162 actively exploited in the wild?

As of now, there is no evidence to suggest that CVE-2021-47162 is being actively exploited in the wild.

Published Mar 25, 2024

Updated

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

tipc: skblinearize the head skb when reassembling msgs

It's not a good idea to append the frag skb to a skb's fraglist if the fraglist already has skbs from elsewhere, such as this skb was created by pskbcopy() where the fraglist was cloned (all the skbs in it were skbget'ed) and shared by multiple skbs.

However, the new appended frag skb should have been only seen by the current skb. Otherwise, it will cause use after free crashes as this appended frag skb are seen by multiple skbs but it only got skbget called once.

The same thing happens with a skb updated by pskbmaypull() with a skbcloned skb. Li Shuang has reported quite a few crashes caused by this when doing testing over macvlan devices:

[] kernel BUG at net/core/skbuff.c:1970! [] Call Trace: [] skbclone+0x4d/0xb0 [] macvlanbroadcast+0xd8/0x160 [macvlan] [] macvlanprocessbroadcast+0x148/0x150 [macvlan] [] processonework+0x1a7/0x360 [] workerthread+0x30/0x390

[] kernel BUG at mm/usercopy.c:102! [] Call Trace: [] checkheapobject+0xd3/0x100 [] checkobjectsize+0xff/0x16b [] simplecopytoiter+0x1c/0x30 [] skbdatagramiter+0x7d/0x310 [] skbdatagramiter+0x2a5/0x310 [] skbcopydatagramiter+0x3b/0x90 [] tipcrecvmsg+0x14a/0x3a0 [tipc] [] sysrecvmsg+0x91/0x150 [] sysrecvmsg+0x7b/0xc0

[] kernel BUG at mm/slub.c:305! [] Call Trace: [] <IRQ> [] kmemcachefree+0x3ff/0x400 [] netifreceiveskbcore+0x12c/0xc40 [] ? kmemcachealloc+0x12e/0x270 [] netifreceiveskbinternal+0x3d/0xb0 [] ? getrxpageinfo+0x8e/0xa0 [be2net] [] bepoll+0x6ef/0xd00 [be2net] [] ? irqexit+0x4f/0x100 [] netrxaction+0x149/0x3b0

...

This patch is to fix it by linearizing the head skb if it has fraglist set in tipcbufappend(). Note that we choose to do this before calling skbunshare(), as skblinearize() will avoid skbcopy(). Also, we can not just drop the fraglist either as the early time.

Affected Software

128 affected componentsFixes available

Linux Linux kernel

Linux Linux kernel>=4.3<4.4.271

Linux Linux kernel>=4.5<4.9.271

Linux Linux kernel>=4.10<4.14.235

Linux Linux kernel>=4.15<4.19.193

Linux Linux kernel>=4.20<5.4.124

Linux Linux kernel>=5.5<5.10.42

Linux Linux kernel>=5.11<5.12.9

Linux Linux kernel=5.13-rc1

Linux Linux kernel=5.13-rc2

Linux Linux kernel=5.13-rc3

ubuntu/linux-azure<4.15.0-1121.134~14.04.1

4.15.0-1121.134~14.04.1

ubuntu/linux-aws*

ubuntu/linux-lts-xenial*

ubuntu/linux-aws-hwe<4.15.0-1109.116~16.04.1

4.15.0-1109.116~16.04.1

ubuntu/linux-azure<4.15.0-1121.134~16.04.1

4.15.0-1121.134~16.04.1

ubuntu/linux-gcp<4.15.0-1106.120~16.04.1

4.15.0-1106.120~16.04.1

ubuntu/linux-hwe<4.15.0-151.157~16.04.1

4.15.0-151.157~16.04.1

ubuntu/linux-oracle<4.15.0-1078.86~16.04.1

4.15.0-1078.86~16.04.1

ubuntu/linux*

ubuntu/linux-aws*

ubuntu/linux-hwe-edge*

ubuntu/linux-kvm*

ubuntu/linux-fips*

ubuntu/linux<4.15.0-151.157

4.15.0-151.157

ubuntu/linux-aws<4.15.0-1109.116

4.15.0-1109.116

ubuntu/linux-aws-5.4<5.4.0-1054.57~18.04.1

5.4.0-1054.57~18.04.1

ubuntu/linux-azure-4.15<4.15.0-1121.134

4.15.0-1121.134

ubuntu/linux-azure-5.4<5.4.0-1055.57~18.04.1

5.4.0-1055.57~18.04.1

ubuntu/linux-gcp-4.15<4.15.0-1106.120

4.15.0-1106.120

ubuntu/linux-gcp-5.4<5.4.0-1049.53~18.04.1

5.4.0-1049.53~18.04.1

ubuntu/linux-hwe-5.4<5.4.0-80.90~18.04.1

5.4.0-80.90~18.04.1

ubuntu/linux-kvm<4.15.0-1097.99

4.15.0-1097.99

ubuntu/linux-oracle<4.15.0-1078.86

4.15.0-1078.86

ubuntu/linux-oracle-5.4<5.4.0-1052.56~18.04.1

5.4.0-1052.56~18.04.1

ubuntu/linux-raspi-5.4<5.4.0-1041.45~18.04.1

5.4.0-1041.45~18.04.1

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-hwe-edge*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-fips<4.15.0-2051.53

4.15.0-2051.53

ubuntu/linux-azure-fips<4.15.0-2033.37

4.15.0-2033.37

ubuntu/linux-fips<4.15.0-1066.75

4.15.0-1066.75

ubuntu/linux-gcp-fips<4.15.0-2016.18

4.15.0-2016.18

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux<5.4.0-80.90

5.4.0-80.90

ubuntu/linux-aws<5.4.0-1054.57

5.4.0-1054.57

ubuntu/linux-azure<5.4.0-1055.57

5.4.0-1055.57

ubuntu/linux-bluefield<5.4.0-1016.19

5.4.0-1016.19

ubuntu/linux-gcp<5.4.0-1049.53

5.4.0-1049.53

ubuntu/linux-gkeop<5.4.0-1021.22

5.4.0-1021.22

ubuntu/linux-kvm<5.4.0-1044.46

5.4.0-1044.46

ubuntu/linux-oracle<5.4.0-1052.56

5.4.0-1052.56

ubuntu/linux-raspi<5.4.0-1041.45

5.4.0-1041.45

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-aws-fips<5.4.0-1069.73+fips2

5.4.0-1069.73+fips2

ubuntu/linux-azure-fips<5.4.0-1073.76+fips1

5.4.0-1073.76+fips1

ubuntu/linux-fips<5.4.0-1031.36

5.4.0-1031.36

ubuntu/linux-gcp-fips<5.4.0-1067.71~20.04.1

5.4.0-1067.71~20.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-nvidia-6.2*

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-raspi-realtime*

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 4.15.0-1121.134~14.04.1
Upgrade
Upgrade ubuntu/linux-aws-hwe to a version that resolves this vulnerability.
Fixed in 4.15.0-1109.116~16.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 4.15.0-1121.134~16.04.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 4.15.0-1106.120~16.04.1
Upgrade
Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.
Fixed in 4.15.0-151.157~16.04.1
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 4.15.0-1078.86~16.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 4.15.0-151.157
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 4.15.0-1109.116
Upgrade
Upgrade ubuntu/linux-aws-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1054.57~18.04.1
Upgrade
Upgrade ubuntu/linux-azure-4.15 to a version that resolves this vulnerability.
Fixed in 4.15.0-1121.134
Upgrade
Upgrade ubuntu/linux-azure-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1055.57~18.04.1
Upgrade
Upgrade ubuntu/linux-gcp-4.15 to a version that resolves this vulnerability.
Fixed in 4.15.0-1106.120
Upgrade
Upgrade ubuntu/linux-gcp-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1049.53~18.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-80.90~18.04.1
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 4.15.0-1097.99
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 4.15.0-1078.86
Upgrade
Upgrade ubuntu/linux-oracle-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1052.56~18.04.1
Upgrade
Upgrade ubuntu/linux-raspi-5.4 to a version that resolves this vulnerability.
Fixed in 5.4.0-1041.45~18.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2051.53
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2033.37
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-1066.75
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 4.15.0-2016.18
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.4.0-80.90
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.4.0-1054.57
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.4.0-1055.57
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.4.0-1016.19
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.4.0-1049.53
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.4.0-1021.22
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.4.0-1044.46
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.4.0-1052.56
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.4.0-1041.45
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1069.73+fips2
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1073.76+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1031.36
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.4.0-1067.71~20.04.1
Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Patch tipc: skb_linearize the head skb when reassembling msgs

Event History

Mar 25, 2024

CVE Published

via MITRE·09:16 AM

Data Sourced

via MITRE·09:16 AM

DescriptionSeverity

Data Sourced

via OSV·10:15 AM

DescriptionSeverityAffected Software

Event

via OSV·10:15 AM

Data Sourced

via NVD·10:15 AM

RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

What is the severity of CVE-2021-47162?

CVE-2021-47162 has been categorized as having a moderate severity level.

How do I fix CVE-2021-47162?

To fix CVE-2021-47162, you should update to the latest stable version of the Linux kernel that includes the patch.

What systems are affected by CVE-2021-47162?

CVE-2021-47162 affects various versions of the Linux kernel that are vulnerable to the described issue.

What is the nature of the vulnerability in CVE-2021-47162?

The vulnerability in CVE-2021-47162 involves improper handling of the skb's frag_list during message reassembly.

Is CVE-2021-47162 actively exploited in the wild?

As of now, there is no evidence to suggest that CVE-2021-47162 is being actively exploited in the wild.

CVE-2021-47162: tipc: skb_linearize the head skb when reassembling msgs

Affected Software

Remediation

Event History

Frequently Asked Questions

What is the severity of CVE-2021-47162?

How do I fix CVE-2021-47162?

What systems are affected by CVE-2021-47162?

What is the nature of the vulnerability in CVE-2021-47162?

Is CVE-2021-47162 actively exploited in the wild?

Company

Resources

Contact