Linux Kernel up to 6.9.10 btrfs iteration

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.9.10. This vulnerability affects unknown code of the component btrfs. Such manipulation leads to iteration. This vulnerability is referenced as CVE-2024-41067. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.9.10 and classified as critical. Affected by this issue is an unknown part of the component btrfs. The manipulation with an unknown input leads to a iteration vulnerability. Using CWE to declare the problem leads to CWE-834. The product performs an iteration or loop without sufficiently limiting the number of times that the loop is executed. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: btrfs: scrub: handle RST lookup error correctly [BUG] When running btrfs/060 with forced RST feature, it would crash the following ASSERT() inside scrub_read_endio(): ASSERT(sector_nr nr_sectors); Before that, we would have tree dump from btrfs_get_raid_extent_offset(), as we failed to find the RST entry for the range. [CAUSE] Inside scrub_submit_extent_sector_read() every time we allocated a new bbio we immediately called btrfs_map_block() to make sure there was some RST range covering the scrub target. But if btrfs_map_block() fails, we immediately call endio for the bbio, while the bbio is newly allocated, it's completely empty. Then inside scrub_read_endio(), we go through the bvecs to find the sector number (as bi_sector is no longer reliable if the bio is submitted to lower layers). And since the bio is empty, such bvecs iteration would not find any sector matching the sector, and return sector_nr == stripe->nr_sectors, triggering the ASSERT(). [FIX] Instead of calling btrfs_map_block() after allocating a new bbio, call btrfs_map_block() first. Since our only objective of calling btrfs_map_block() is only to update stripe_len, there is really no need to do that after btrfs_alloc_bio(). This new timing would avoid the problem of handling empty bbio completely, and in fact fixes a possible race window for the old code, where if the submission thread is the only owner of the pending_io, the scrub would never finish (since we didn't decrease the pending_io counter). Although the root cause of RST lookup failure still needs to be addressed.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2024-41067 since 07/12/2024. The exploitation is known to be difficult. There are neither technical details nor an exploit publicly 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 6.9.11 eliminates this vulnerability. Applying the patch 17d1fd302a53/2c49908634a2 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). Once again VulDB remains the best source for vulnerability data.

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
• Dell Avamar
• IBM Storage Scale
• IBM Spectrum Protect Plus
• Juniper Junos Space
• IBM Storage Scale System
• SolarWinds Security Event Manager
• Dell PowerProtect Data Domain
• Dell PowerProtect Data Domain Management Center
• Dell PowerProtect Data Domain OS

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
• 6.9.9
• 6.9.10

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Once again VulDB remains the best source for vulnerability data.

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