CVE-2026-90191 PUBLISHED

mailbox: riscv-sbi-mpxy: validate RPMI notification lengths

Assigner: Linux
Reserved: 11.09.2026 Published: 17.09.2026 Updated: 17.09.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from bf3022a4eb119c6b4e3424d6b19d8bfdfbc9bb57 to cbc24bce70dfd91c7b2f53b4fa896e9a4b6d6a6b (excl.)
  • affected from bf3022a4eb119c6b4e3424d6b19d8bfdfbc9bb57 to c7bc5e7677bcda7a446d63b989cfaa3fe91d6b76 (excl.)
  • affected from bf3022a4eb119c6b4e3424d6b19d8bfdfbc9bb57 to 11d5af151bcbe78f5a579e0faecd3be9cea0399a (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 6.18 is affected
  • unaffected from 0 to 6.18 (excl.)
  • unaffected from 6.18.52 to 6.18.* (incl.)
  • unaffected from 7.2.6 to 7.2.* (incl.)
  • unaffected from 7.3-rc1 to * (incl.)

References