Linux Kernel up to 5.4.118/5.10.36/5.11.20/5.12.3 KVM kvm_io_bus_unregister_dev null pointer dereference

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 5.4.118/5.10.36/5.11.20/5.12.3. This issue affects the function kvm_io_bus_unregister_dev of the component KVM. The manipulation leads to null pointer dereference. This vulnerability is uniquely identified as CVE-2021-47060. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.4.118/5.10.36/5.11.20/5.12.3 (Operating System). It has been rated as critical. This issue affects the function kvm_io_bus_unregister_dev of the component KVM. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: KVM: Stop looking for coalesced MMIO zones if the bus is destroyed Abort the walk of coalesced MMIO zones if kvm_io_bus_unregister_dev() fails to allocate memory for the new instance of the bus. If it can't instantiate a new bus, unregister_dev() destroys all devices _except_ the target device. But, it doesn't tell the caller that it obliterated the bus and invoked the destructor for all devices that were on the bus. In the coalesced MMIO case, this can result in a deleted list entry dereference due to attempting to continue iterating on coalesced_zones after future entries (in the walk) have been deleted. Opportunistically add curly braces to the for-loop, which encompasses many lines but sneaks by without braces due to the guts being a single if statement.

The weakness was disclosed 03/01/2024. It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2021-47060 since 02/29/2024. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 5.4.119, 5.10.37, 5.11.21, 5.12.4 or 5.13 eliminates this vulnerability. Applying the patch 7d1bc32d6477/2a20592baff5/168e82f640ed/50cbad42bfea/5d3c4c79384a is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.4.118
• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.10.36
• 5.11.0
• 5.11.1
• 5.11.2
• 5.11.3
• 5.11.4
• 5.11.5
• 5.11.6
• 5.11.7
• 5.11.8
• 5.11.9
• 5.11.10
• 5.11.11
• 5.11.12
• 5.11.13
• 5.11.14
• 5.11.15
• 5.11.16
• 5.11.17
• 5.11.18
• 5.11.19
• 5.11.20
• 5.12.0
• 5.12.1
• 5.12.2
• 5.12.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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