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Linux Kernel EUVDEUVD-2026-48782

| CVE-2026-64438 HIGH
Use After Free (CWE-416)
2026-07-25 Linux GHSA-j99q-5p83-43j8
Linux Use After Free Memory Corruption
8.8
CVSS 3.1 · Vendor: Linux
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Severity by source

Vendor (Linux) PRIMARY
8.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
vuln.today AI
7.8 HIGH

Race condition requires precise concurrent teardown timing (AC:H); VF tenant low-privilege local access (PR:L); S:C because VM user can affect host kernel via SR-IOV.

3.1 AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
SUSE
5.5 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Red Hat
7.0 MEDIUM
qualitative

Primary rating from Vendor (Linux).

CVSS VectorVendor: Linux

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

6
Metadata Corrected
Sep 16, 2026 - 09:40 vuln.today
tag: Information Disclosure removed
Analysis Generated
Jul 27, 2026 - 05:54 vuln.today
CVSS changed
Jul 27, 2026 - 05:22 NVD
8.8 (HIGH)
Patch available
Jul 25, 2026 - 11:18 EUVD
CVE Published
Jul 25, 2026 - 08:51 cve.org
HIGH 8.8
CVE Published
Jul 25, 2026 - 08:51 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

crypto: qat - fix VF2PF work teardown race in adf_disable_sriov()

The VF2PF interrupt handler queues PF-side response work that stores a raw pointer to per-VF state (struct adf_accel_vf_info). Currently, adf_disable_sriov() destroys per-VF mutexes and frees vf_info without stopping new VF2PF work or waiting for in-flight workers to complete. A concurrently scheduled or already queued worker can then dereference freed memory.

This manifests as a use-after-free when KASAN is enabled:

BUG: KASAN: null-ptr-deref in mutex_lock+0x76/0xe0 Write of size 8 at addr 0000000000000260 by task kworker/24:2/... Workqueue: qat_pf2vf_resp_wq adf_iov_send_resp [intel_qat] Call Trace: kasan_report+0x119/0x140 mutex_lock+0x76/0xe0 adf_gen4_pfvf_send+0xd4/0x1f0 [intel_qat] adf_recv_and_handle_vf2pf_msg+0x290/0x360 [intel_qat] adf_iov_send_resp+0x8c/0xe0 [intel_qat] process_one_work+0x6ac/0xfd0 worker_thread+0x4dd/0xd30 kthread+0x326/0x410 ret_from_fork+0x33b/0x670

Add a PF-local flag, vf2pf_disabled, that gates work queueing, worker processing, and interrupt re-enabling during teardown. Set this flag atomically with the hardware interrupt mask inside adf_disable_all_vf2pf_interrupts(). After masking, synchronize the AE cluster MSI-X interrupt and flush the PF response workqueue before tearing down per-VF locks and state so all in-flight work completes before vf_info is destroyed.

Introduce adf_enable_all_vf2pf_interrupts() to clear the flag and unmask all VF2PF interrupts under the same lock when SR-IOV is re-enabled. This ensures the software flag and hardware state transition atomically on both the enable and disable paths.

AnalysisAI

Use-after-free in the Linux kernel's Intel QuickAssist Technology (QAT) SR-IOV driver allows a local low-privileged attacker - including a VM tenant with a VF assigned - to corrupt host kernel memory by racing VF2PF workqueue processing against SR-IOV teardown in adf_disable_sriov(). The VF2PF interrupt handler enqueues work that holds raw pointers to per-VF state (struct adf_accel_vf_info); adf_disable_sriov() freed that state without draining in-flight workers, enabling a concurrent worker to deref freed memory. No public exploit is known at time of analysis, and EPSS is 0.22% (13th percentile), indicating negligible observed exploitation pressure despite the 8.8 CVSS score.

Technical ContextAI

The Intel QuickAssist Technology driver (intel_qat kernel module) supports SR-IOV (Single Root I/O Virtualization), splitting a physical QAT accelerator into virtual functions for VM tenants. The Physical Function (PF) handles VF-to-PF (VF2PF) interrupt-driven messages by scheduling response work on the dedicated qat_pf2vf_resp_wq workqueue, with each work item holding a raw pointer to per-VF state (struct adf_accel_vf_info). The teardown path adf_disable_sriov() destroyed per-VF mutexes and freed vf_info without (1) masking VF2PF hardware interrupts atomically before freeing, (2) preventing new work from being queued after the flag transition, or (3) flushing the workqueue before teardown. This is a classic CWE-416 (Use After Free) race: the kernel provides KASAN instrumentation that surfaced the null-pointer deref at mutex_lock+0x76, triggered when adf_gen4_pfvf_send attempted to lock an already-freed mutex inside the freed vf_info struct. The fix introduces a vf2pf_disabled flag set atomically with the hardware interrupt mask, adds synchronize_irq and workqueue flush before teardown, and introduces symmetric enable/disable helpers to keep software flag and hardware interrupt state consistent. CPE: cpe:2.3:a:linux:linux:*. Vulnerable from kernel 4.3 (commit ed8ccaef52fa03fb03cff45b380f72c9f869f273) through all stable branches before the fix commits.

RemediationAI

The primary fix is to upgrade to patched kernel stable releases: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.4, or 7.2-rc1. The upstream fix commits are available at git.kernel.org (218c2836b398, 446b4d77599c, 5d916c1eae19, f344a369d038, 51144032248c, 49cd5ac6de8d, 6e92b28cd74f, 277281c10c63). Ubuntu users should apply USN-8726-1 or USN-8727-1 via standard package updates. As a compensating control where patching is not immediately possible, administrators can disable SR-IOV on QAT devices (remove VF assignments and set the VF count to 0 via sysfs) - this eliminates the VF2PF interrupt path entirely, eliminating the race, but at the cost of losing hardware acceleration for VMs. Alternatively, restricting the intel_qat module from loading in non-SR-IOV environments via module blacklisting prevents exposure if QAT is not required. Do not rely on KASAN as a mitigation - it detects but does not prevent exploitation.

Same weakness CWE-416 – Use After Free

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CVE-2009-4324 HIGH POC
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CVE-2015-0313 CRITICAL POC
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CVE-2015-5122 CRITICAL POC
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Same technique Use After Free

View all
CVE-2015-5119 CRITICAL POC
9.8
CVE-2014-0322 HIGH POC
8.8
CVE-2012-4792 HIGH POC
8.8
CVE-2009-4324 HIGH POC
7.8
CVE-2015-0313 CRITICAL POC
9.8
CVE-2015-5122 CRITICAL POC
9.8
CVE-2013-2551 HIGH POC
8.8
CVE-2012-4969 HIGH POC
8.1

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 16.0 Affected

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EUVD-2026-48782 vulnerability details – vuln.today
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