Linux Kernel up to 6.9.8 fs_bdev_thaw denial of service

Summaryinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.9.8. This vulnerability affects the function fs_bdev_thaw. Such manipulation leads to denial of service. This vulnerability is documented as CVE-2024-42149. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.9.8 and classified as problematic. Affected by this issue is the function fs_bdev_thaw. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: fs: don't misleadingly warn during thaw operations The block device may have been frozen before it was claimed by a filesystem. Concurrently another process might try to mount that frozen block device and has temporarily claimed the block device for that purpose causing a concurrent fs_bdev_thaw() to end up here. The mounter is already about to abort mounting because they still saw an elevanted bdev->bd_fsfreeze_count so get_bdev_super() will return NULL in that case. For example, P1 calls dm_suspend() which calls into bdev_freeze() before the block device has been claimed by the filesystem. This brings bdev->bd_fsfreeze_count to 1 and no call into fs_bdev_freeze() is required. Now P2 tries to mount that frozen block device. It claims it and checks bdev->bd_fsfreeze_count. As it's elevated it aborts mounting. In the meantime P3 called dm_resume(). P3 sees that the block device is already claimed by a filesystem and calls into fs_bdev_thaw(). P3 takes a passive reference and realizes that the filesystem isn't ready yet. P3 puts itself to sleep to wait for the filesystem to become ready. P2 now puts the last active reference to the filesystem and marks it as dying. P3 gets woken, sees that the filesystem is dying and get_bdev_super() fails.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2024-42149 since 07/29/2024. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 210060 (Ubuntu 22.04 LTS / 24.04 LTS : Linux kernel kernel vulnerabilities (USN-7089-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.9.9 eliminates this vulnerability. Applying the patch 25b1e3906e05/2ae4db5647d8 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.

The vulnerability is also documented in the databases at Tenable (210060) and CERT Bund (WID-SEC-2024-1722). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• IBM InfoSphere Guardium
• Oracle Linux
• NetApp FAS
• NetApp ActiveIQ Unified Manager
• Siemens SIMATIC S7
• Oracle VM
• IBM Security Guardium
• RESF Rocky Linux
• Broadcom Brocade SANnav
• Dell PowerScale
• Open Source Linux Kernel
• IBM QRadar SIEM
• Dell integrated Dell Remote Access Controller
• IBM Storage Scale
• IBM Spectrum Protect Plus
• Juniper Junos Space
• IBM Storage Scale System
• SolarWinds Security Event Manager

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.9.0
• 6.9.1
• 6.9.2
• 6.9.3
• 6.9.4
• 6.9.5
• 6.9.6
• 6.9.7
• 6.9.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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