UBUNTU-CVE-2024-46795: Null Pointer Dereference

Q: Which systems are exposed to this issue?

Systems running an affected Ubuntu kernel package listed in the advisory are exposed when the ksmbd SMB server is in use. The affected package set includes linux, linux-azure, linux-gcp, linux-gke, linux-riscv, linux-realtime, linux-fips, and linux-azure-fde.

Q: What must an attacker be able to do to trigger the failure?

The issue involves SMB session setup on a reused connection when that connection is used for session binding. Exploitation requires network access and low privileges; no user interaction is required.

Q: What is the practical impact?

The missing preauthentication hash can be dereferenced while creating an SMB 3.1.1 encryption key, causing a kernel NULL pointer dereference. This can result in a denial of service through a kernel crash.

Published Sep 18, 2024

Updated

In the Linux kernel, the following vulnerability has been resolved: ksmbd: unset the binding mark of a reused connection Steve French reported null pointer dereference error from sha256 lib. cifs.ko can send session setup requests on reused connection. If reused connection is used for binding session, conn->binding can still remain true and generatepreauthhash() will not set sess->PreauthHashValue and it will be NULL. It is used as a material to create an encryption key in ksmbdgensmb311encryptionkey. ->PreauthHashValue cause null pointer dereference error from cryptoshashupdate(). BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: errorcode(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 8 PID: 429254 Comm: kworker/8:39 Hardware name: LENOVO 20MAS08500/20MAS08500, BIOS N2CET69W (1.52 ) Workqueue: ksmbd-io handleksmbdwork [ksmbd] RIP: 0010:libsha256basedoupdate.isra.0+0x11e/0x1d0 [sha256ssse3] <TASK> ? showregs+0x6d/0x80 ? die+0x24/0x80 ? pagefaultoops+0x99/0x1b0 ? douseraddrfault+0x2ee/0x6b0 ? excpagefault+0x83/0x1b0 ? asmexcpagefault+0x27/0x30 ? pfxsha256transformrorx+0x10/0x10 [sha256ssse3] ? libsha256basedoupdate.isra.0+0x11e/0x1d0 [sha256ssse3] ? pfxsha256transformrorx+0x10/0x10 [sha256ssse3] ? pfxsha256transformrorx+0x10/0x10 [sha256ssse3] sha256update+0x77/0xa0 [sha256ssse3] sha256avx2update+0x15/0x30 [sha256ssse3] cryptoshashupdate+0x1e/0x40 hmacupdate+0x12/0x20 cryptoshashupdate+0x1e/0x40 generatekey+0x234/0x380 [ksmbd] generatesmb3encryptionkey+0x40/0x1c0 [ksmbd] ksmbdgensmb311encryptionkey+0x72/0xa0 [ksmbd] ntlmauthenticate.isra.0+0x423/0x5d0 [ksmbd] smb2sesssetup+0x952/0xaa0 [ksmbd] processrequest+0xa3/0x1d0 [ksmbd] handleksmbdwork+0x1c4/0x2f0 [ksmbd] handleksmbdwork+0x2d/0xa0 [ksmbd] processonework+0x16c/0x350 workerthread+0x306/0x440 ? pfxworkerthread+0x10/0x10 kthread+0xef/0x120 ? pfxkthread+0x10/0x10 retfromfork+0x44/0x70 ? pfxkthread+0x10/0x10 retfromforkasm+0x1b/0x30 </TASK>

Affected Software

140 affected componentsFixes available

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<5.15.0-1072.78~20.04.1

5.15.0-1072.78~20.04.1

ubuntu/linux-azure-5.15<5.15.0-1078.87~20.04.1

5.15.0-1078.87~20.04.1

ubuntu/linux-gcp-5.15<5.15.0-1071.79~20.04.1

5.15.0-1071.79~20.04.1

ubuntu/linux-gkeop-5.15<5.15.0-1055.62~20.04.1

5.15.0-1055.62~20.04.1

ubuntu/linux-hwe-5.15<5.15.0-125.135~20.04.1

5.15.0-125.135~20.04.1

ubuntu/linux-ibm-5.15<5.15.0-1065.68~20.04.1

5.15.0-1065.68~20.04.1

ubuntu/linux-intel-iotg-5.15<5.15.0-1067.73~20.04.1

5.15.0-1067.73~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-125.135~20.04.1

5.15.0-125.135~20.04.1

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1032.32~20.04.1

5.15.0-1032.32~20.04.1

ubuntu/linux-oracle-5.15<5.15.0-1070.76~20.04.1

5.15.0-1070.76~20.04.1

ubuntu/linux-riscv-5.15<5.15.0-1068.72~20.04.1

5.15.0-1068.72~20.04.1

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<5.15.0-125.135

5.15.0-125.135

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1072.78

5.15.0-1072.78

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1020.22~22.04.1

6.8.0-1020.22~22.04.1

ubuntu/linux-azure<5.15.0-1075.84

5.15.0-1075.84

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1020.23~22.04.1

6.8.0-1020.23~22.04.1

ubuntu/linux-azure-fde<5.15.0-1076.85.1

5.15.0-1076.85.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1071.79

5.15.0-1071.79

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1019.21~22.04.1

6.8.0-1019.21~22.04.1

ubuntu/linux-gke<5.15.0-1069.75

5.15.0-1069.75

ubuntu/linux-gkeop<5.15.0-1055.62

5.15.0-1055.62

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-50.51~22.04.1

6.8.0-50.51~22.04.1

ubuntu/linux-ibm<5.15.0-1065.68

5.15.0-1065.68

ubuntu/linux-ibm-6.8<6.8.0-1017.17~22.04.1

6.8.0-1017.17~22.04.1

ubuntu/linux-intel-iotg<5.15.0-1067.73

5.15.0-1067.73

ubuntu/linux-kvm<5.15.0-1069.74

5.15.0-1069.74

ubuntu/linux-lowlatency<5.15.0-125.135

5.15.0-125.135

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-50.51.1~22.04.1

6.8.0-50.51.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1067.68

5.15.0-1067.68

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1019.21~22.04.1

6.8.0-1019.21~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1032.32

5.15.0-1032.32

ubuntu/linux-nvidia-tegra-igx<5.15.0-1020.20

5.15.0-1020.20

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1070.76

5.15.0-1070.76

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1017.18~22.04.1

6.8.0-1017.18~22.04.1

ubuntu/linux-raspi<5.15.0-1065.68

5.15.0-1065.68

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-50.51.1~22.04.1

6.8.0-50.51.1~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1038.42

5.15.0-1038.42

ubuntu/linux-bluefield<5.15.0-1056.58

5.15.0-1056.58

ubuntu/linux-intel-iot-realtime<5.15.0-1066.68

5.15.0-1066.68

ubuntu/linux-realtime<5.15.0-1073.81

5.15.0-1073.81

ubuntu/linux-realtime-6.8<6.8.1-1013.14~22.04.1

6.8.1-1013.14~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1072.78+fips1

5.15.0-1072.78+fips1

ubuntu/linux-azure-fips<5.15.0-1075.84+fips1

5.15.0-1075.84+fips1

ubuntu/linux-fips<5.15.0-125.135+fips1

5.15.0-125.135+fips1

ubuntu/linux-gcp-fips<5.15.0-1071.79+fips1

5.15.0-1071.79+fips1

ubuntu/linux<6.8.0-50.51

6.8.0-50.51

ubuntu/linux-aws<6.8.0-1020.22

6.8.0-1020.22

ubuntu/linux-azure<6.8.0-1020.23

6.8.0-1020.23

ubuntu/linux-gcp<6.8.0-1019.21

6.8.0-1019.21

ubuntu/linux-gke<6.8.0-1015.19

6.8.0-1015.19

ubuntu/linux-gkeop<6.8.0-1002.4

6.8.0-1002.4

ubuntu/linux-ibm<6.8.0-1017.17

6.8.0-1017.17

ubuntu/linux-lowlatency<6.8.0-50.51.1

6.8.0-50.51.1

ubuntu/linux-nvidia<6.8.0-1019.21

6.8.0-1019.21

ubuntu/linux-nvidia-lowlatency<6.8.0-1019.21.1

6.8.0-1019.21.1

ubuntu/linux-oem-6.8<6.8.0-1018.18

6.8.0-1018.18

ubuntu/linux-oracle<6.8.0-1017.18

6.8.0-1017.18

ubuntu/linux-raspi<6.8.0-1016.18

6.8.0-1016.18

ubuntu/linux-riscv<6.8.0-50.51.1

6.8.0-50.51.1

ubuntu/linux-xilinx<6.8.0-1017.18

6.8.0-1017.18

ubuntu/linux-raspi-realtime<6.8.0-2015.16

6.8.0-2015.16

ubuntu/linux-realtime<6.8.1-1013.14

6.8.1-1013.14

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 5.15.0-1072.78~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1078.87~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1071.79~20.04.1
Upgrade
Upgrade ubuntu/linux-gkeop-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1055.62~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-125.135~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1065.68~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1067.73~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-125.135~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1032.32~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1070.76~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1068.72~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-125.135
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1072.78
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1020.22~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.84
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1020.23~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1076.85.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1071.79
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1019.21~22.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1069.75
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1055.62
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-50.51~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1065.68
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1017.17~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1067.73
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1069.74
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-125.135
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-50.51.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1067.68
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1019.21~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1032.32
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1020.20
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1070.76
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1017.18~22.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1065.68
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-50.51.1~22.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1038.42
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1056.58
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1066.68
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1073.81
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1013.14~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1072.78+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.84+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-125.135+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1071.79+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-50.51
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1020.22
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1020.23
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1019.21
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1015.19
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1002.4
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1017.17
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-50.51.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1019.21
Upgrade
Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-1019.21.1
Upgrade
Upgrade ubuntu/linux-oem-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1018.18
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1017.18
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.8.0-1016.18
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 6.8.0-50.51.1
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 6.8.0-2015.16
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1013.14
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78+fips1

Event History

Sep 18, 2024

CVE Published

via OSV·08:15 AM

Data Sourced

via OSV·08:15 AM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which systems are exposed to this issue?

Systems running an affected Ubuntu kernel package listed in the advisory are exposed when the ksmbd SMB server is in use. The affected package set includes linux, linux-azure, linux-gcp, linux-gke, linux-riscv, linux-realtime, linux-fips, and linux-azure-fde.

What must an attacker be able to do to trigger the failure?

The issue involves SMB session setup on a reused connection when that connection is used for session binding. Exploitation requires network access and low privileges; no user interaction is required.

What is the practical impact?

The missing preauthentication hash can be dereferenced while creating an SMB 3.1.1 encryption key, causing a kernel NULL pointer dereference. This can result in a denial of service through a kernel crash.

UBUNTU-CVE-2024-46795: Null Pointer Dereference

Affected Software

Remediation

Event History

Frequently Asked Questions

Which systems are exposed to this issue?

What must an attacker be able to do to trigger the failure?

What is the practical impact?

Company

Resources

Contact

Frequently Asked Questions

Which systems are exposed to this issue?

What must an attacker be able to do to trigger the failure?

What is the practical impact?