Linux Kernel up to 6.7.11/6.8.2 raid456 mddev_suspend deadlock

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.7.11/6.8.2. It has been declared as critical. This issue affects the function mddev_suspend of the component raid456. Executing a manipulation can lead to deadlock. This vulnerability appears as CVE-2024-26962. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.7.11/6.8.2. It has been declared as critical. This vulnerability affects the function mddev_suspend of the component raid456. The manipulation with an unknown input leads to a deadlock vulnerability. The CWE definition for the vulnerability is CWE-833. The product contains multiple threads or executable segments that are waiting for each other to release a necessary lock, resulting in deadlock. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape For raid456, if reshape is still in progress, then IO across reshape position will wait for reshape to make progress. However, for dm-raid, in following cases reshape will never make progress hence IO will hang: 1) the array is read-only; 2) MD_RECOVERY_WAIT is set; 3) MD_RECOVERY_FROZEN is set; After commit c467e97f079f ("md/raid6: use valid sector values to determine if an I/O should wait on the reshape") fix the problem that IO across reshape position doesn't wait for reshape, the dm-raid test shell/lvconvert-raid-reshape.sh start to hang: [root@fedora ~]# cat /proc/979/stack [] wait_woken+0x7d/0x90 [] raid5_make_request+0x929/0x1d70 [raid456] [] md_handle_request+0xc2/0x3b0 [md_mod] [] raid_map+0x2c/0x50 [dm_raid] [] __map_bio+0x251/0x380 [dm_mod] [] dm_submit_bio+0x1f0/0x760 [dm_mod] [] __submit_bio+0xc2/0x1c0 [] submit_bio_noacct_nocheck+0x17f/0x450 [] submit_bio_noacct+0x2bc/0x780 [] submit_bio+0x70/0xc0 [] mpage_readahead+0x169/0x1f0 [] blkdev_readahead+0x18/0x30 [] read_pages+0x7c/0x3b0 [] page_cache_ra_unbounded+0x1ab/0x280 [] force_page_cache_ra+0x9e/0x130 [] page_cache_sync_ra+0x3b/0x110 [] filemap_get_pages+0x143/0xa30 [] filemap_read+0xdc/0x4b0 [] blkdev_read_iter+0x75/0x200 [] vfs_read+0x272/0x460 [] ksys_read+0x7a/0x170 [] __x64_sys_read+0x1c/0x30 [] do_syscall_64+0xc6/0x230 [] entry_SYSCALL_64_after_hwframe+0x6c/0x74 This is because reshape can't make progress. For md/raid, the problem doesn't exist because register new sync_thread doesn't rely on the IO to be done any more: 1) If array is read-only, it can switch to read-write by ioctl/sysfs; 2) md/raid never set MD_RECOVERY_WAIT; 3) If MD_RECOVERY_FROZEN is set, mddev_suspend() doesn't hold 'reconfig_mutex', hence it can be cleared and reshape can continue by sysfs api 'sync_action'. However, I'm not sure yet how to avoid the problem in dm-raid yet. This patch on the one hand make sure raid_message() can't change sync_thread() through raid_message() after presuspend(), on the other hand detect the above 3 cases before wait for IO do be done in dm_suspend(), and let dm-raid requeue those IO.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2024-26962 since 02/19/2024. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 210815 (RHEL 9 : kernel (RHSA-2024:9315)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.7.12, 6.8.3 or 6.9-rc1 eliminates this vulnerability. Applying the patch 5943a34bf6ba/a8d249d770cb/41425f96d7aa 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 (210815) and CERT Bund (WID-SEC-2024-1008). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• Oracle VM
• EMC Avamar
• IBM QRadar SIEM
• Dell NetWorker
• IBM Security Guardium
• RESF Rocky Linux
• Broadcom Brocade SANnav
• Open Source Linux Kernel
• IBM Business Automation Workflow
• IBM Spectrum Protect Plus
• Dell Avamar
• Juniper Junos Space
• IBM DataPower Gateway
• IBM Storage Scale System
• SolarWinds Security Event Manager
• Dell PowerProtect Data Domain
• Dell PowerScale OneFS

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.7.0
• 6.7.1
• 6.7.2
• 6.7.3
• 6.7.4
• 6.7.5
• 6.7.6
• 6.7.7
• 6.7.8
• 6.7.9
• 6.7.10
• 6.7.11
• 6.8.0
• 6.8.1
• 6.8.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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