From mboxrd@z Thu Jan 1 00:00:00 1970 From: AL-KERNEL To: kernel-cve@kernelcve.org Subject: [CVE-2026-98730][MODERATE 7.0] Bluetooth: btintel_pcie: reject oversized TX packets in send_frame() Date: Sat, 24 Oct 2026 13:24:54 -0400 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-AL-KERNEL-CVE: CVE-2026-98730 X-AL-KERNEL-Priority: MODERATE 7.0 X-AL-KERNEL-Severity: MODERATE 7.0 X-AL-KERNEL-Base-Severity: MODERATE X-AL-KERNEL-KPANIC: YES X-AL-KERNEL-ActionableScore: 5 X-AL-KERNEL-ActionableScore-Lower: unknown X-AL-KERNEL-Commit: 3d6ba6be9bef13edcd4ad74f7cfdd0c34db4d2bc List-Id: CVE: CVE-2026-98730 Priority: MODERATE 7.0 AL-KERNEL base severity: MODERATE KPANIC flag: YES Patch: Bluetooth: btintel_pcie: reject oversized TX packets in send_frame() Commit: 3d6ba6be9bef13edcd4ad74f7cfdd0c34db4d2bc Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3d6ba6be9bef13edcd4ad74f7cfdd0c34db4d2bc Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98730 Analysis date: Sat, 24 Oct 2026 13:24:54 -0400 ActionableScore: 5 ActionableScore lower bound: unknown Actionable bucket: Actionable Moderate / Strong Important candidate requiring manual review Manual review required: YES Summary: An HCI_CHANNEL_USER sender can overflow a fixed 4096-byte Bluetooth PCIe DMA buffer with attacker-controlled packet bytes. ====================================================================== ABOUT THIS REPORT ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98730 is available here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98730 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: MODERATE 7.0 Manual review required: YES A detailed explanation of the methodology and priority rules is included at the end of this message. ====================================================================== AL-KERNEL CLASSIFICATION RESULT ====================================================================== CVE-2026-98730 MODERATE https://www.kernelcve.org/list/?q=CVE-2026-98730 CHECK WITH IMPACT FROM ORIG NN LOW | AEGIS IMPACT MODERATE_KPANIC AEGIS_AS=3 LEGACY=MODERATE_KPANIC RESULT=SAME (final reconciliation agrees; DECISION: both MODERATE_KPANIC) Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H';*CWE-787;CWE-120;*CWE-20;Other CVSS 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H';BEST CVSS score: '7.8';DESCR 'btintel_pcie_prepare_tx prepends a 4 byte PCIe header and copies attacker controlled skb data into a fixed 4096 byte DMA buffer without previously limiting the packet length. A local process with access to HCI_CHANNEL_USER can therefore cause an attacker controlled out of bounds write beyond the DMA allocation. For the CVSS the PR:L value is selected because triggering requires a local user or process able to access the Bluetooth HCI user channel, although capabilities, device ownership, and exclusive channel requirements can further restrict practical reachability. The demonstrated primitive supports at least kernel memory corruption and denial of service. Reliable privilege escalation depends on the placement and use of memory adjacent to the DMA buffer, so high confidentiality and integrity impact is reserved for the paranoid score. Automated impact decision path. The original SimpleNet classifier selected LOW. The primary LLM estimated paranoid CVSS 7.8 and the production ActionableScore returned 5 with recommendation Actionable Moderate / Strong Important candidate requiring manual review. The production rules then evaluated CVSS thresholds and ActionableScore thresholds. Recorded rule transitions were CVSS and initial triage stage LOW to MODERATE_KPANIC because the ActionableScore threshold rule was applied. The legacy KP specialist produced a review artifact and its decision was processed by the applicable KP rules. The legacy FD or DH downgrade specialist has no review artifact for this run. Exact triggered rule markers were INCREASED_TO_MODERATE7_FROM_LOW_BASED_ON_GUESSCVSS_AND_ACTIONABLESCOREHIGHER4. The independent weaker Aegis shadow evaluated CVSS 3.3 and ActionableScore 3 with primitive class CLASS_B and manual review REQUIRED. Its independently reconciled impact was MODERATE_KPANIC. The shadow agreed with the final production impact and aggregation did not change that impact. The final reported impact is MODERATE_KPANIC.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate / Strong Important candidate requiring manual review (with actual score 5) MAYBE SIMPLEFIX ERRORPATH SKB DMAorINTERRUPT LINUS PACKET KPANIC INCREASED_TO_MODERATE7_FROM_LOW_BASED_ON_GUESSCVSS_AND_ACTIONABLESCOREHIGHER4 - - checked ====================================================================== ACTIONABLESCORE ANALYSIS ====================================================================== ActionableScore=5 PrimitiveClass=CLASS_A RealUAF=NO HostAdminRequired=UNKNOWN NamespaceScopedPrivilege=UNKNOWN ImportantCandidate=YES ManualReview=REQUIRED AutoDowngradeAllowed=NO RequiresHostUID0=UNKNOWN AuthorizationDecisionBypass=NO ProtectedResourceImpact=NONE B4PendingReview=NO B4PendingConfirmed=NO 1. ActionableScore * Raw base score: 3. * Conservative score: 5. Manual-review safety floor raises 3 -> 5 for a confirmed attacker-influenced kernel OOB write. * Raw paranoid score: 3. * Paranoid score: 5. No additional speculative exploit points awarded. * Final recommended bucket: **Actionable Moderate / Strong Important candidate requiring manual review**:: 2. Signal breakdown * +2 — Strong corruption primitive: attacker-influenced `skb->len` and packet bytes reach a `memcpy()` into a fixed 4096-byte DMA buffer after a four-byte header is prepended, producing a confirmed out-of-bounds write. * +1 — Plausible kernel crash/strong DoS from overwriting memory beyond the DMA allocation. * +0 — No privilege penalty: effective HCI_CHANNEL_USER privilege requirements are unresolved, so host-admin privilege cannot be assumed. * +0 — No local-unprivileged bonus: possession of HCI_CHANNEL_USER access is stated, but normal-user or namespace-scoped access for the complete trigger is not established. * +0 — No separate memory-layout point because allocation/copy-size mismatch is the same OOB-write primitive. * Not shown: arbitrary target selection, identified adjacent victim, controlled reclaim, callback overwrite, disclosure, LPE, or proven confidentiality/integrity impact. * NEW52/B5-R does not apply: no retry-accumulated index or later corrupted-state consumer is shown. 3. Reachability analysis A local process with HCI_CHANNEL_USER access can submit the oversized skb on affected Intel PCIe Bluetooth hardware. The evidence does not resolve device ownership, capability checks, exclusivity requirements, capability namespace, or whether ordinary users can obtain that channel. No rare-hardware penalty is applied merely because this is device-specific, and no timing race is required. 4. Primitive and severity reading The primitive is an attacker-payload heap/DMA-buffer OOB write, not a UAF or fixed harmless overwrite. The destination starts as a fixed DMA buffer, but attacker-controlled length and bytes can cross its allocation boundary. This is CLASS_A even though the adjacent object and practical exploitation are unknown. The shown consequence is kernel memory corruption with plausible crash; LPE or arbitrary write remains speculative. ImportantCandidate is YES and auto-downgrade is disallowed because the concrete write primitive would otherwise be lost. 5. One-sentence report phrase An HCI_CHANNEL_USER sender can overflow a fixed 4096-byte Bluetooth PCIe DMA buffer with attacker-controlled packet bytes. 6. Manual review advice MANUAL CHECK REQUIRED Determine HCI channel privilege scope, allocation adjacency, overwrite extent, and whether corrupted neighboring DMA or kernel objects are subsequently consumed. 7. Call-site confidence Call-site confidence: high ====================================================================== UPSTREAM PATCH SUMMARY ====================================================================== Patch: Bluetooth: btintel_pcie: reject oversized TX packets in send_frame() Commit: 3d6ba6be9bef13edcd4ad74f7cfdd0c34db4d2bc Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3d6ba6be9bef13edcd4ad74f7cfdd0c34db4d2bc Commit description: btintel_pcie_send_frame() eventually copies skb->data into a fixed BTINTEL_PCIE_BUFFER_SIZE (4096) DMA buffer via memcpy() in btintel_pcie_prepare_tx(), with a 4-byte PCIe type header prepended. A user-space process with HCI_CHANNEL_USER access can inject an oversized packet and overflow the buffer. Reject packets larger than BTINTEL_PCIE_BUFFER_SIZE - BTINTEL_PCIE_HCI_TYPE_LEN on entry. Fixes: 6e65a09 ("Bluetooth: btintel_pcie: Add *setup* function to download firmware") Cc: stable@vger.kernel.org Signed-off-by: Chandrashekar Devegowda Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman Changed files: drivers/bluetooth/btintel_pcie.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=3d6ba6be9bef13edcd4ad74f7cfdd0c34db4d2bc ====================================================================== DETAILED REPORT METHODOLOGY ====================================================================== The original Linux kernel CVE announcement for CVE-2026-98730 can be found here: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-98730 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: AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H The Best / paranoid CVSS score: 7.8 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: 5 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: MODERATE KPANIC detected for this report: YES Published priority for this report (same as in Subject): MODERATE 7.0 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).