From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-45992][LOW] ALSA: caiaq: Fix potentially leftover ep1_in_urb at error path Date: Wed, 27 May 2026 17:47:06 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-45992 X-AL-KERNEL-Priority: LOW X-AL-KERNEL-Severity: LOW X-AL-KERNEL-Base-Severity: LOW X-AL-KERNEL-KPANIC: NO X-AL-KERNEL-ActionableScore: 0 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: be62c8bb03b6aec3790a943d4a7567d4d73b8be9 List-Id: CVE: CVE-2026-45992 Priority: LOW AL-KERNEL base severity: LOW KPANIC flag: NO Patch: ALSA: caiaq: Fix potentially leftover ep1_in_urb at error path Commit: be62c8bb03b6aec3790a943d4a7567d4d73b8be9 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=be62c8bb03b6aec3790a943d4a7567d4d73b8be9 Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45992 Analysis date: Wed, 27 May 2026 17:47:06 -0400 ActionableScore: 0 ActionableScore lower bound: unknown Actionable bucket: Ordinary Moderate / Low-like Manual review required: NO Summary: No one-sentence report phrase was found. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45992 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45992 The original announcement does not normally provide a security severity estimate, CVSS assessment, or enough information to determine whether the reported kernel bug represents a practically relevant security issue. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. It combines an autonomous classifier with LLM-assisted technical analysis and a separate ActionableScore mechanism. The purpose of this report is to prioritize Linux kernel CVEs before manual review, identify cases that require prompt investigation, and support automatic closure of issues that are unlikely to have meaningful security impact. Published priority for this report: LOW Manual review required: NO A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-45992 LOW CHECK Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:P/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L';*CWE-401;*CWE-772;CWE-459;CWE-703;BEST CVSS score: '2.1';DESCR 'ALSA caiaq can leave the internal ep1_in_urb submitted when setup_card() fails after partial probe initialization. A malformed or incompatible USB audio device can trigger the error path, causing a leftover URB or leaked USB request state until later cleanup. For the CVSS the PR:N is used because no software privileges are needed once the device is physically attached, but the attack vector is physical and usually requires device insertion or equivalent USB emulation. The issue is not network reachable and does not provide a kernel memory corruption primitive. Impact is limited denial of service through resource leakage or dangling USB activity during probe failure.';NO MANUAL CHECK; ,and ActionableScore result is Ordinary Moderate / Low-like (with actual score 0) SKIP CVE-2026-45992 SKIP The Fixes patch not applied yet, so unlikely that actual: 28abd224db4a49560b452115bca3672a20e45b2f YES NO NO unknown MAYBE USB INIT SIMPLEFIX LEAK ERRORPATH HARDWARE LINUS - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=0 1. ActionableScore * Conservative score: 0 * Paranoid score: 0 * Final recommended bucket: **Ordinary Moderate / Low-like**:: 2. Signal breakdown * Availability/resource cleanup concern: +1. A submitted `ep1_in_urb` may be left over on a probe error path, causing a resource leak or dangling USB request state. * Physical-only trigger: -2. Triggering requires a malformed/incompatible USB device or equivalent USB emulation attached to the host. * Rare driver-specific exposure: -1. This is limited to the ALSA `caiaq` USB driver and a partial probe failure path. * No memory corruption signal. The patch only routes failure through existing URB cleanup. * No confidentiality, integrity, privilege escalation, or network reachability signal. 3. Reachability analysis A physically attached malformed or incompatible CAIAQ USB audio device can reach the error path if `setup_card()` fails after `ep1_in_urb` was submitted. No Linux software privileges are needed once the device is attached, but practical attack requires physical access or USB emulation. Containers do not materially affect reachability because USB probing happens at the host driver layer. 4. Severity interpretation This behaves like a Low-like resource cleanup bug. The realistic impact is a leftover URB or small resource leak during probe failure. There is no evidence of UAF, OOB access, arbitrary write, information disclosure, or privilege escalation. 5. One-sentence report phrase A malformed CAIAQ USB audio device can trigger a probe error path that leaves `ep1_in_urb` submitted, causing only limited USB resource leakage or dangling URB state. 6. Manual review recommendation NO MANUAL CHECK NEEDED. This is a physical, driver-specific cleanup leak with no memory corruption, security-boundary bypass, or remote trigger. ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: ALSA: caiaq: Fix potentially leftover ep1_in_urb at error path Commit: be62c8bb03b6aec3790a943d4a7567d4d73b8be9 Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=be62c8bb03b6aec3790a943d4a7567d4d73b8be9 Commit description: The previous fix for handling the error from setup_card() missed that an internal URB cdev->ep1_in_urb might have been already submitted beforehand. In the normal case, this URB gets killed at the disconnection, but in the error path, we didn't do it, hence there can be a potential leak. Fix it in the error path for setup_card(), too. Fixes: 28abd22 ("ALSA: caiaq: Handle probe errors properly") Cc: Link: https://patch.msgid.link/20260427123819.890185-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman Changed files: sound/usb/caiaq/device.c Diff excerpt: Not included in this email. See the upstream URL for the full patch. Full patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=be62c8bb03b6aec3790a943d4a7567d4d73b8be9 ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-45992 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-45992 The original CVE announcement normally does not include a security-level estimate. In particular, it may not contain a CVSS assessment, an impact level, or enough information to determine whether the reported bug is a practically relevant security issue. One purpose of this parallel CVE list is to provide that missing technical and prioritization information. The original goal of the AL-KERNEL project was to prioritize Linux kernel CVE analysis automatically before manual review. The system can also help identify non-security issues that may be suitable for automatic closure. This report was generated by AL-KERNEL, an AI-assisted Linux kernel vulnerability analysis system developed by Alexander Larkin. The first analysis stage combines an autonomous classifier with additional LLM-based analysis. The autonomous classifier runs locally on a CPU and is based on a backpropagation neural network. Together, these mechanisms produce a technical vulnerability description, identify likely weakness types, estimate CVSS severity, and provide input for ActionableScore. Two CVSS estimates are retained because incomplete kernel vulnerability information often permits more than one defensible interpretation: Conservative CVSS vector: Not available The Best / paranoid CVSS vector: AV:P/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L The Best / paranoid CVSS score: 2.1 The conservative vector represents a lower-impact interpretation. The Best/paranoid vector intentionally represents a plausible upper-bound interpretation and should not automatically be treated as demonstrated real-world impact. CVSS may also need to be adjusted for a particular Linux deployment, because actual reachability, privileges, enabled kernel configuration, hardware, namespaces, exposed device nodes, and other environmental conditions can differ significantly between systems. A separate ActionableScore mechanism evaluates practical remediation urgency. Its analysis may include reachability, attack prerequisites, subsystem exposure, memory-corruption characteristics, denial-of-service reliability, and possible confidentiality, integrity, or privilege-escalation impact. Conservative ActionableScore: unknown Paranoid ActionableScore: 0 The final base severity is taken directly from the second tab-separated field of the AL-KERNEL classification result. ActionableScore does not replace or independently override that final AL-KERNEL decision, and if ActionableScore adjusted impact level of ALKERNEL, then you would see self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7. For an AL-KERNEL result of MODERATE, this report uses the following additional presentation split: ActionableScore below 5 -> MODERATE REGULAR ActionableScore 5 or more -> MODERATE 7.0 The distinction between MODERATE REGULAR and MODERATE 7.0 makes it possible to identify Moderate issues that should receive manual analysis and fixes before lower-priority MODERATE REGULAR issues. In many cases, MODERATE REGULAR fixes may wait for a later rebase or routine update. There is one override in which MODERATE REGULAR becomes MODERATE 7.0 even when the ActionableScore is below 5. When the AL-KERNEL result contains the KPANIC flag, a MODERATE result is always presented as MODERATE 7.0. The KPANIC flag selected with few regexps without usage of AI at all, so it helps to detect cases when Kernel Crash happens and similar (to filter False-Negative results from the LLM usage). KPANIC indicates that a reliable kernel crash, kernel panic, or similarly serious kernel availability impact was identified by the classification workflow. AL-KERNEL base severity for this report: LOW KPANIC detected for this report: NO Published priority for this report (same as in Subject): LOW These results are intended to support engineering triage. They are machine-generated estimates, and cases marked for manual review should be validated by a human security engineer before final disposition. For more info read docs linked from here: https://kernelcve.org/ (and you can submit you own patch there to generate such a report for non-existant CVE-id yet). Note that in many cases this AI tool selects higher severity, than real is (means you can expect Importants instead of Moderate 7.0 or Moderates 7.0 instead of regular Moderates). If you see such cases, please use reply email interface to add additional manual analyses info to this particular CVE. And please, please, let me know when you see Lows instead of Importants or Important instead of Low (because particular for such cases I need to tune this AI tool to make it better for this one and next similar). My contact email for such notifications is alexanjelausa@gmail.com (and both send reply to CVE record itself too and see "reply" button below for howto reply).