CVE-2026-74737: net: ethernet: ti: am65-cpsw-nuss: Fix port_id extraction from SRC TAG
In the Linux kernel, the following vulnerability has been resolved:
net: ethernet: ti: am65-cpsw-nuss: Fix portid extraction from SRC TAG
On the packet reception path, the ID of the MAC Port on which the packet was received, is embedded in the RX DMA Descriptor's metadata. The ID is extracted using the helper function cppi5descgettagsids() which fills in the 16-bit Source Tag into the 'portid' variable. However, it is only the lower 8-bits of the 16-bit Source Tag that represent the MAC Port ID, while the upper 8-bits are Hardware-Reserved and carry an arbitrary value. With the existing logic, sporadic kernel crash is observed due to the subsequent driver code accessing out-of-bound memory because of an invalid portid.
Hence, fix the portid extraction logic to use only the lower 8-bits of the Source Tag as the MAC Port ID.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Linux kernelto a version that resolves this vulnerability.Patch net: ethernet: ti: am65-cpsw-nuss: Fix port_id extraction from SRC TAG
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Systems using the Linux kernel TI AM65 CPSW NUSS Ethernet driver are exposed on the packet reception path. The issue is triggered when received-packet metadata contains an arbitrary value in the hardware-reserved upper 8 bits of the Source Tag.
What is the practical impact of the faulty port ID handling?
The driver can treat the full 16-bit Source Tag as a MAC port ID even though only its lower 8 bits are valid. This can lead subsequent driver code to access memory out of bounds and cause a sporadic kernel crash.
How can the issue be mitigated if an update cannot be applied immediately?
The provided data does not identify a configuration workaround. The corrective change is to extract and use only the lower 8 bits of the Source Tag as the MAC port ID.