Executive brief
A vulnerability in the Linux kernel's network driver for Ocelot hardware can cause the system to crash when configuring network interfaces. This occurs specifically when adding a network interface to a Link Aggregation Group (LAG), which is a common method for combining multiple network connections for redundancy or speed. An attacker with local access could exploit this to cause a denial-of-service, disrupting network operations and system availability.
Technical details
A NULL pointer dereference exists in the ocelot_set_aggr_pgids() function within the MSCC Ocelot network driver (drivers/net/ethernet/mscc/ocelot.c). The vulnerability is triggered when the driver attempts to access port properties for unused ports that are represented as NULL pointers in the ocelot_vsc7514.c frontend. This occurs during the configuration of Link Aggregation Groups (LAG). A local attacker can trigger this crash to cause a denial-of-service. The issue has been resolved by adding a validation check for the port pointer before dereferencing it. The fix has been backported to various stable kernel branches including 5.15.y, 6.1.y, 6.6.y, and 6.12.y.
Affected products
- Linux Linux 5.12 to 6.13.y
- Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.6
Timeline
- 2025-12-25: disclosed: Initial patch submitted by Jerry Wu
- 2026-01-04: patched: Patch committed to mainline kernel
- 2026-01-23: advisory: NVD publication date
References
- https://git.kernel.org/stable/c/03fb1708b7d1e76aecebf767ad059c319845039f
- https://git.kernel.org/stable/c/2985712dc76dfa670eb7fd607c09d4d48e5f5c6e
- https://git.kernel.org/stable/c/34f3ff52cb9fa7dbf04f5c734fcc4cb6ed5d1a95
- https://git.kernel.org/stable/c/8767f238b0e6c3d0b295ac6dce9fbe6a99bd1b9d
- https://git.kernel.org/stable/c/b17818307446c5a8d925a39a792261dbfa930041
- https://git.kernel.org/stable/c/f490af47bbee02441e356a1e0b86e3b3dd5120ff
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html