CVE-2026-45952

Summary

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

eth: fbnic: Add validation for MTU changes

Increasing the MTU beyond the HDS threshold causes the hardware to fragment packets across multiple buffers. If a single-buffer XDP program is attached, the driver will drop all multi-frag frames. While we can't prevent a remote sender from sending non-TCP packets larger than the MTU, this will prevent users from inadvertently breaking new TCP streams.

Traditionally, drivers supported XDP with MTU less than 4Kb (packet per page). Fbnic currently prevents attaching XDP when MTU is too high. But it does not prevent increasing MTU after XDP is attached.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux1b0a3950dbd4fa278dc33401a4faba2a23307a16 < d7eaa006c0444a5d4671be7efe6dbb33ef8b515eaffected
LinuxLinux1b0a3950dbd4fa278dc33401a4faba2a23307a16 < 03399063aa0c67fd8bdfd69467ddb849bb3b97dfaffected
LinuxLinux1b0a3950dbd4fa278dc33401a4faba2a23307a16 < ccd8e87748ad083047d6c8544c5809b7f96cc8dfaffected
LinuxLinux6.18affected
LinuxLinux0 < 6.18unaffected
LinuxLinux6.18.14 <= 6.18.*unaffected
LinuxLinux6.19.4 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References