CVE-2026-90191

In the Linux kernel, the following vulnerability has been resolved: mailbox: riscv-sbi-mpxy: validate RPMI notification lengths The SBI return value controls how many bytes are copied from shared memory into the RPMI notification buffer. It is not validated against the negotiated shared-memory size before that copy. The event walker also uses a reversed loop condition and can inspect a short event record. Validate the complete notification length before copying it, iterate only while a full event header remains, and stop when a declared event payload extends beyond the copied notification data.

• https://git.kernel.org/stable/c/11d5af151bcbe78f5a579e0faecd3be9cea0399a
• https://git.kernel.org/stable/c/c7bc5e7677bcda7a446d63b989cfaa3fe91d6b76
• https://git.kernel.org/stable/c/cbc24bce70dfd91c7b2f53b4fa896e9a4b6d6a6b