CVE-2022-49720
Published: 26 February 2025
Summary
CVE-2022-49720 is a high-severity Improper Validation of Array Index (CWE-129) vulnerability in Linux Linux Kernel. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 4.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and RA-5 (Vulnerability Monitoring and Scanning).
Deeper analysis
CVE-2022-49720 is an array-index-out-of-bounds vulnerability in the Linux kernel's block layer, specifically within the blk_mq_alloc_request_hctx() function due to improper handling of offline queues. The issue manifests as an UBSAN report where index 512 exceeds the bounds of a 512-element array in block/blk-mq.h:135. It is triggered in NVMe-related tests like nvme/004 and involves call traces through NVMe components such as nvme_core, nvme_fabrics, nvme_loop, and nvmf_dev_write.
A local attacker with low privileges (PR:L) can exploit this vulnerability with low attack complexity (AC:L) and no user interaction (UI:N), as indicated by its CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). Successful exploitation could result in high impacts to confidentiality, integrity, and availability, potentially allowing arbitrary code execution, data corruption, or system crashes via out-of-bounds memory access in the block multi-queue (blk-mq) subsystem.
Mitigation requires updating to patched Linux kernel versions via the provided stable branch commits, including 14dc7a18abbe4176f5626c13c333670da8e06aa1, 7fa28a7c3d74933a4fc22d341b60927952f31c19, b202a0bd2580ee5b0453772c46d464152fafff73, and b5e65ef044d627effdc2599040b6d204e003f955, which fix the offline queue handling in blk_mq_alloc_request_hctx().
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2022-54515
Vulnerability details
In the Linux kernel, the following vulnerability has been resolved: block: Fix handling of offline queues in blk_mq_alloc_request_hctx() This patch prevents that test nvme/004 triggers the following: UBSAN: array-index-out-of-bounds in block/blk-mq.h:135:9 index 512 is out of range for type 'long…
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unsigned int [512]' Call Trace: show_stack+0x52/0x58 dump_stack_lvl+0x49/0x5e dump_stack+0x10/0x12 ubsan_epilogue+0x9/0x3b __ubsan_handle_out_of_bounds.cold+0x44/0x49 blk_mq_alloc_request_hctx+0x304/0x310 __nvme_submit_sync_cmd+0x70/0x200 [nvme_core] nvmf_connect_io_queue+0x23e/0x2a0 [nvme_fabrics] nvme_loop_connect_io_queues+0x8d/0xb0 [nvme_loop] nvme_loop_create_ctrl+0x58e/0x7d0 [nvme_loop] nvmf_create_ctrl+0x1d7/0x4d0 [nvme_fabrics] nvmf_dev_write+0xae/0x111 [nvme_fabrics] vfs_write+0x144/0x560 ksys_write+0xb7/0x140 __x64_sys_write+0x42/0x50 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Local kernel OOB write in blk-mq (NVMe path) with low-priv trigger enables direct privilege escalation to arbitrary code execution or system crash.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Mandates timely remediation through patching of the specific array-index-out-of-bounds flaw in the Linux kernel's blk_mq_alloc_request_hctx() function.
Enables vulnerability scanning to identify the presence of CVE-2022-49720 in Linux kernel block layer components for prompt remediation.
Provides memory protection mechanisms that mitigate exploitation of the out-of-bounds array access in the kernel's multi-queue block subsystem.