UBUNTU-CVE-2024-56678: Use After Free

Q: Which systems are exposed to this issue?

The issue affects the listed Ubuntu Linux kernel packages on PowerPC systems where /proc/kcore is available and contains unmapped KFENCE objects. The affected package list includes linux-realtime, linux-azure, linux-gcp, linux-gke, linux-gkeop, linux-riscv, linux-fips, and linux-hwe-edge.

Q: What access does an attacker need to trigger it?

The provided severity vector indicates local access, low attack complexity, and low privileges are required; no user interaction is needed. A read of /proc/kcore, such as running dd if=/proc/kcore of=/dev/null bs=1M, can trigger the faulty path.

Q: How can administrators identify likely exposure or attempted triggering?

Review whether /proc/kcore can be read on affected PowerPC systems and check for processes reading it, including dd commands using /proc/kcore as input. Kernel logs may show KFENCE reports such as invalid reads or use-after-free reads in copy_from_kernel_nofault during read_kcore_iter.

Published Dec 28, 2024

Updated

In the Linux kernel, the following vulnerability has been resolved: powerpc/mm/fault: Fix kfence page fault reporting copyfromkernelnofault() can be called when doing read of /proc/kcore. /proc/kcore can have some unmapped kfence objects which when read via copyfromkernelnofault() can cause page faults. Since nofault() functions define their own fixup table for handling fault, use that instead of asking kfence to handle such faults. Hence we search the exception tables for the nip which generated the fault. If there is an entry then we let the fixup table handler handle the page fault by returning an error from within dopagefault(). This can be easily triggered if someone tries to do dd from /proc/kcore. eg. dd if=/proc/kcore of=/dev/null bs=1M Some example false negatives: =============================== BUG: KFENCE: invalid read in copyfromkernelnofault+0x9c/0x1a0 Invalid read at 0xc0000000fdff0000: copyfromkernelnofault+0x9c/0x1a0 0xc00000000665f950 readkcoreiter+0x57c/0xa04 procregreaditer+0xe4/0x16c vfsread+0x320/0x3ec ksysread+0x90/0x154 systemcallexception+0x120/0x310 systemcallvectoredcommon+0x15c/0x2ec BUG: KFENCE: use-after-free read in copyfromkernelnofault+0x9c/0x1a0 Use-after-free read at 0xc0000000fe050000 (in kfence-#2): copyfromkernelnofault+0x9c/0x1a0 0xc00000000665f950 readkcoreiter+0x57c/0xa04 procregreaditer+0xe4/0x16c vfsread+0x320/0x3ec ksysread+0x90/0x154 systemcallexception+0x120/0x310 systemcallvectoredcommon+0x15c/0x2ec

Affected Software

150 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-hwe-edge*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-5.15<5.15.0-1080.87~20.04.1

5.15.0-1080.87~20.04.1

ubuntu/linux-azure-5.15<5.15.0-1086.95~20.04.1

5.15.0-1086.95~20.04.1

ubuntu/linux-gcp-5.15<5.15.0-1081.90~20.04.1

5.15.0-1081.90~20.04.1

ubuntu/linux-hwe-5.15<5.15.0-136.147~20.04.1

5.15.0-136.147~20.04.1

ubuntu/linux-ibm-5.15<5.15.0-1074.77~20.04.1

5.15.0-1074.77~20.04.1

ubuntu/linux-intel-iotg-5.15<5.15.0-1077.83~20.04.1

5.15.0-1077.83~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-135.146~20.04.1

5.15.0-135.146~20.04.1

ubuntu/linux-oracle-5.15<5.15.0-1077.83~20.04.1

5.15.0-1077.83~20.04.1

ubuntu/linux-riscv-5.15<5.15.0-1075.79~20.04.1

5.15.0-1075.79~20.04.1

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-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.8*

ubuntu/linux-intel-5.13*

ubuntu/linux-nvidia-tegra-5.15<5.15.0-1039.39~20.04.1

5.15.0-1039.39~20.04.1

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<5.15.0-135.146

5.15.0-135.146

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1080.87

5.15.0-1080.87

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1027.29~22.04.1

6.8.0-1027.29~22.04.1

ubuntu/linux-azure<5.15.0-1084.93

5.15.0-1084.93

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1027.32~22.04.1

6.8.0-1027.32~22.04.1

ubuntu/linux-azure-fde<5.15.0-1084.93.1

5.15.0-1084.93.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1079.88

5.15.0-1079.88

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1028.30~22.04.1

6.8.0-1028.30~22.04.1

ubuntu/linux-gke<5.15.0-1077.83

5.15.0-1077.83

ubuntu/linux-gkeop<5.15.0-1062.70

5.15.0-1062.70

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-58.60~22.04.1

6.8.0-58.60~22.04.1

ubuntu/linux-ibm<5.15.0-1072.75

5.15.0-1072.75

ubuntu/linux-ibm-6.8<6.8.0-1024.24~22.04.1

6.8.0-1024.24~22.04.1

ubuntu/linux-intel-iot-realtime<5.15.0-1073.75

5.15.0-1073.75

ubuntu/linux-intel-iotg<5.15.0-1075.81

5.15.0-1075.81

ubuntu/linux-kvm<5.15.0-1076.81

5.15.0-1076.81

ubuntu/linux-lowlatency<5.15.0-135.146

5.15.0-135.146

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-58.60.1~22.04.1

6.8.0-58.60.1~22.04.1

ubuntu/linux-nvidia<5.15.0-1074.75

5.15.0-1074.75

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1026.29~22.04.1

6.8.0-1026.29~22.04.1

ubuntu/linux-nvidia-tegra<5.15.0-1033.33

5.15.0-1033.33

ubuntu/linux-nvidia-tegra-igx<5.15.0-1021.21

5.15.0-1021.21

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1077.83

5.15.0-1077.83

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1024.25~22.04.1

6.8.0-1024.25~22.04.1

ubuntu/linux-raspi<5.15.0-1074.77

5.15.0-1074.77

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-58.60.1~22.04.1

6.8.0-58.60.1~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-xilinx-zynqmp<5.15.0-1044.48

5.15.0-1044.48

ubuntu/linux-bluefield<5.15.0-1062.64

5.15.0-1062.64

ubuntu/linux-realtime<5.15.0-1080.88

5.15.0-1080.88

ubuntu/linux-realtime-6.8<6.8.1-1020.21~22.04.1

6.8.1-1020.21~22.04.1

ubuntu/linux-aws-fips*

ubuntu/linux-azure-fips*

ubuntu/linux-fips*

ubuntu/linux-gcp-fips*

ubuntu/linux-aws-fips<5.15.0-1080.87+fips1

5.15.0-1080.87+fips1

ubuntu/linux-azure-fips<5.15.0-1083.92+fips1

5.15.0-1083.92+fips1

ubuntu/linux-fips<5.15.0-135.146+fips1

5.15.0-135.146+fips1

ubuntu/linux-gcp-fips<5.15.0-1079.88+fips1

5.15.0-1079.88+fips1

ubuntu/linux<6.8.0-58.60

6.8.0-58.60

ubuntu/linux-aws<6.8.0-1027.29

6.8.0-1027.29

ubuntu/linux-azure<6.8.0-1027.32

6.8.0-1027.32

ubuntu/linux-azure-6.11<6.11.0-1012.12~24.04.1

6.11.0-1012.12~24.04.1

ubuntu/linux-azure-nvidia<6.8.0-1014.15

6.8.0-1014.15

ubuntu/linux-gcp<6.8.0-1028.30

6.8.0-1028.30

ubuntu/linux-gcp-6.11<6.11.0-1011.11~24.04.1

6.11.0-1011.11~24.04.1

ubuntu/linux-gke<6.8.0-1023.27

6.8.0-1023.27

ubuntu/linux-gkeop<6.8.0-1010.12

6.8.0-1010.12

ubuntu/linux-ibm<6.8.0-1024.24

6.8.0-1024.24

ubuntu/linux-lowlatency<6.8.0-58.60.1

6.8.0-58.60.1

ubuntu/linux-nvidia<6.8.0-1026.29

6.8.0-1026.29

ubuntu/linux-nvidia-6.11<6.11.0-1007.7

6.11.0-1007.7

ubuntu/linux-nvidia-lowlatency<6.8.0-1026.29.1

6.8.0-1026.29.1

ubuntu/linux-nvidia-tegra<6.8.0-1008.8

6.8.0-1008.8

ubuntu/linux-oem-6.11<6.11.0-1015.15

6.11.0-1015.15

ubuntu/linux-oem-6.8<6.8.0-1026.26

6.8.0-1026.26

ubuntu/linux-oracle<6.8.0-1024.25

6.8.0-1024.25

ubuntu/linux-raspi<6.8.0-1028.32

6.8.0-1028.32

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv<6.8.0-58.60.1

6.8.0-58.60.1

ubuntu/linux-xilinx<6.8.0-1017.18

6.8.0-1017.18

ubuntu/linux-raspi-realtime<6.8.0-2023.24

6.8.0-2023.24

ubuntu/linux-realtime<6.8.1-1020.21

6.8.1-1020.21

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 5.15.0-1080.87~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1086.95~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1081.90~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-136.147~20.04.1
Upgrade
Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.77~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.79~20.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1039.39~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.87
Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1027.29~22.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1084.93
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1027.32~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1084.93.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1079.88
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.30~22.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1062.70
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1072.75
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1024.24~22.04.1
Upgrade
Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1073.75
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1075.81
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1076.81
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.75
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.29~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 5.15.0-1033.33
Upgrade
Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.
Fixed in 5.15.0-1021.21
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1077.83
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1024.25~22.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1074.77
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60.1~22.04.1
Upgrade
Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.
Fixed in 5.15.0-1044.48
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1062.64
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.88
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1020.21~22.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1080.87+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1083.92+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-135.146+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 5.15.0-1079.88+fips1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1027.29
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1027.32
Upgrade
Upgrade ubuntu/linux-azure-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1012.12~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1014.15
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.30
Upgrade
Upgrade ubuntu/linux-gcp-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1011.11~24.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1023.27
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1010.12
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1024.24
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.29
Upgrade
Upgrade ubuntu/linux-nvidia-6.11 to a version that resolves this vulnerability.
Fixed in 6.11.0-1007.7
Upgrade
Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.29.1
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 6.11.0-1015.15
Upgrade
Upgrade ubuntu/linux-oem-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1026.26
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1024.25
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.8.0-1028.32
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 6.8.0-58.60.1
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 6.8.0-2023.24
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1020.21
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-78.78+fips1

Event History

Dec 28, 2024

CVE Published

via OSV·10:15 AM

Data Sourced

via OSV·10:15 AM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which systems are exposed to this issue?

The issue affects the listed Ubuntu Linux kernel packages on PowerPC systems where /proc/kcore is available and contains unmapped KFENCE objects. The affected package list includes linux-realtime, linux-azure, linux-gcp, linux-gke, linux-gkeop, linux-riscv, linux-fips, and linux-hwe-edge.

What access does an attacker need to trigger it?