CVE-2026-68183 Overview
CVE-2026-68183 affects the Linux kernel's Intel Stratix10 service layer firmware driver (stratix10-svc). The vulnerability involves memory leaks and list corruption bugs in the driver's allocation and lookup paths. When gen_pool_alloc() fails, the driver does not free the associated pmem structure, causing a memory leak. A related defect issues an erroneous list_del(&svc_data_mem) on failed lookups, corrupting the list head. The upstream fix reworks pmem allocation to use kzalloc() with explicit kfree() in the free path, matching its list-managed lifetime, and removes the incorrect list_del call.
Critical Impact
Memory leaks and kernel list-head corruption in the stratix10-svc driver can degrade system stability and lead to kernel state corruption on affected Intel Stratix10 SoC platforms.
Affected Products
- Linux kernel builds including the firmware/stratix10-svc driver
- Systems targeting Intel Stratix10 SoC FPGA platforms
- Distributions shipping unpatched kernels referenced in the upstream stable commits
Discovery Timeline
- 2026-08-10 - CVE-2026-68183 published to NVD
- 2026-08-10 - Last updated in NVD database
Technical Details for CVE-2026-68183
Vulnerability Analysis
The stratix10-svc driver manages shared memory regions for communication with Intel Stratix10 firmware services. The driver tracks allocations through a linked list of svc_data_mem entries, with each entry represented by a pmem structure. The defective code path allocated pmem using devm_kzalloc(), which ties the buffer's lifetime to the device rather than to the list entry it represents. When gen_pool_alloc() failed inside the allocation routine, the driver returned without releasing pmem, producing a memory leak on every failed request.
A second defect appeared in the lookup path. On a failed lookup, the code executed list_del(&svc_data_mem) against the list head itself rather than a valid list entry. This unlinked the head node from its own list, corrupting subsequent list traversals and insertions.
Root Cause
The root cause is a lifetime mismatch between the pmem allocation strategy and the list-managed ownership model, combined with an incorrect list operation on a failed lookup. devm_kzalloc() is unsuitable when callers must free objects individually as list entries are removed. The list_del on the list head reflects a logic error where the head sentinel was mistaken for an entry.
Attack Vector
The issue is triggered through the kernel path that allocates shared memory via the Stratix10 service layer. A local caller that induces gen_pool_alloc() failures or failed memory lookups can leak kernel memory and corrupt driver state. The vulnerability is scoped to platforms where the stratix10-svc driver is loaded and reachable, and no remote attack surface is described in the upstream advisory.
No public exploit code is available. The upstream patch commits are the authoritative technical references for reproduction and analysis. See the Linux kernel stable tree commit 4f2db41a09eb and related commits 8e93a083456d, 9119ceb76e98, 95f702e37296, and fff6e5ff0318 for the full source-level fix.
Detection Methods for CVE-2026-68183
Indicators of Compromise
- Growing kernel slab consumption tied to the stratix10-svc driver visible in /proc/slabinfo or slabtop output
- Kernel warnings or oops messages referencing list_del, list corruption, or stratix10-svc in dmesg
- Repeated gen_pool_alloc() failure messages preceding memory pressure on Stratix10 SoC platforms
Detection Strategies
- Compare running kernel version against the fixed commits published in the Linux stable tree to confirm patch presence
- Enable CONFIG_DEBUG_LIST in kernel builds to surface list-head corruption at runtime rather than as latent instability
- Audit workloads that repeatedly invoke Stratix10 firmware service ioctls for abnormal failure rates
Monitoring Recommendations
- Collect and centralize dmesg output from Stratix10 SoC nodes for anomaly review
- Track long-term kernel memory usage trends to identify slow leaks in firmware driver caches
- Alert on kernel WARN or BUG events referencing the stratix10-svc module
How to Mitigate CVE-2026-68183
Immediate Actions Required
- Inventory systems running kernels that include the stratix10-svc driver, focusing on Intel Stratix10 SoC deployments
- Apply the stable-tree kernel updates that include the referenced fix commits
- Reboot affected hosts after patching to load the corrected driver into memory
Patch Information
The fix was merged into the Linux stable trees through commits 4f2db41a09eb, 8e93a083456d, 9119ceb76e98, 95f702e37296, and fff6e5ff0318. The patch frees pmem on the gen_pool_alloc() error path, switches allocation from devm_kzalloc() to kzalloc() with explicit kfree(), and removes the erroneous list_del(&svc_data_mem) on failed lookups.
Workarounds
- Unload the stratix10-svc module on systems that do not require Intel Stratix10 firmware services
- Restrict local access to userspace interfaces that reach the driver until patches are deployed
- Monitor kernel memory usage and reboot systems that show sustained leaks pending patch rollout
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
