Linux Kernel up to 6.0.7 null_blk.ko allocation of resources

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.0.7. It has been declared as problematic. This affects the function null_blk.ko. Such manipulation leads to allocation of resources. This vulnerability is referenced as CVE-2022-49901. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.0.7 and classified as problematic. Affected by this issue is the function null_blk.ko. The manipulation with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: blk-mq: Fix kmemleak in blk_mq_init_allocated_queue There is a kmemleak caused by modprobe null_blk.ko unreferenced object 0xffff8881acb1f000 (size 1024): comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S...... backtrace: [] kmalloc_node_trace+0x22/0x60 [] blk_mq_alloc_and_init_hctx+0x289/0x350 [] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0 [] blk_mq_init_allocated_queue+0x48c/0x1440 [] __blk_mq_alloc_disk+0xc8/0x1c0 [] 0xffffffffc450d69d [] 0xffffffffc4538392 [] do_one_initcall+0xd0/0x4f0 [] do_init_module+0x1a4/0x680 [] load_module+0x6249/0x7110 [] __do_sys_finit_module+0x140/0x200 [] do_syscall_64+0x35/0x80 [] entry_SYSCALL_64_after_hwframe+0x46/0xb0 That is because q->ma_ops is set to NULL before blk_release_queue is called. blk_mq_init_queue_data blk_mq_init_allocated_queue blk_mq_realloc_hw_ctxs for (i = 0; i nr_hw_queues; i++) { old_hctx = xa_load(&q->hctx_table, i); if (!blk_mq_alloc_and_init_hctx(.., i, ..)) [1] if (!old_hctx) break; xa_for_each_start(&q->hctx_table, j, hctx, j) blk_mq_exit_hctx(q, set, hctx, j); [2] if (!q->nr_hw_queues) [3] goto err_hctxs; err_exit: q->mq_ops = NULL; [4] blk_put_queue blk_release_queue if (queue_is_mq(q)) [5] blk_mq_release(q); [1]: blk_mq_alloc_and_init_hctx failed at i != 0. [2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and will be cleaned up in blk_mq_release. [3]: q->nr_hw_queues is 0. [4]: Set q->mq_ops to NULL. [5]: queue_is_mq returns false due to [4]. And blk_mq_release will not be called. The hctxs in q->unused_hctx_list are leaked. To fix it, call blk_release_queue in exception path.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2022-49901 since 05/01/2025. The exploitation is known to be difficult. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 249320 (EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-1979)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.0.8 eliminates this vulnerability. Applying the patch 2dc97e15a54b7bdf457848aa8c663c98a24e58a6/943f45b9399ed8b2b5190cbc797995edaa97f58f 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 (249320) and CERT Bund (WID-SEC-2025-0922). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Dell Avamar
• Open Source Linux Kernel
• IBM DataPower Gateway
• Dell NetWorker
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3
• 6.0.4
• 6.0.5
• 6.0.6
• 6.0.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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

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