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CVE-2026-93186

cxl/mbox: Clamp mailbox output allocation to the payload size

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 6.6.160, 6.12.110, 6.18.52, 7.2.6
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: cxl/mbox: Clamp mailbox output allocation to the payload size CXL_MEM_SEND_COMMAND bounds the user's in.size to the mailbox payload size but leaves out.size unbounded, then cxl_mbox_cmd_ctor() calls kvzalloc(out.size). A large out.size drives a huge allocation, above INT_MAX it WARNs and taints, and with panic_on_warn=1 it panics. The transport __cxl_pci_mbox_send_cmd() already clamps the response copy to min(out.size, payload_size, device len), so the output buffer is never written beyond payload_size. Clamp the allocation to payload_size too, matching the RAW path.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    Version range not reported

  • Linux Linux

    5.12

  • KernelLinux

    From 5.12.0 · fixed in 6.6.160; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 6

git.kernel.org