CVE-2026-31464 PUBLISHED

scsi: ibmvfc: Fix OOB access in ibmvfc_discover_targets_done()

Assigner: Linux
Reserved: 09.03.2026 Published: 22.04.2026 Updated: 22.04.2026

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

scsi: ibmvfc: Fix OOB access in ibmvfc_discover_targets_done()

A malicious or compromised VIO server can return a num_written value in the discover targets MAD response that exceeds max_targets. This value is stored directly in vhost->num_targets without validation, and is then used as the loop bound in ibmvfc_alloc_targets() to index into disc_buf[], which is only allocated for max_targets entries. Indices at or beyond max_targets access kernel memory outside the DMA-coherent allocation. The out-of-bounds data is subsequently embedded in Implicit Logout and PLOGI MADs that are sent back to the VIO server, leaking kernel memory.

Fix by clamping num_written to max_targets before storing it.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3 to d842348f8a00d5b1d7358f207eb34ffcf5b16df3 (excl.)
  • affected from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3 to a007246cb6c9ebdc93dafbf63cc2d43d98f402cc (excl.)
  • affected from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3 to 394a1cac3c12fdd7d77f19ccfd222ab5ff87ef89 (excl.)
  • affected from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3 to 4ed727e35b0ab17d3eeeb1e8023768396e2be161 (excl.)
  • affected from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3 to d1466bf991b2343cf2ba8336e440c8faf3cbb780 (excl.)
  • affected from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3 to 786f10b1966e485046839f992e89f2c18cbd1983 (excl.)
  • affected from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3 to bae4df0a643fa7f84663473aa3082a9c2ed139db (excl.)
  • affected from 072b91f9c6510d0ec4a49d07dbc318760c7da7b3 to 61d099ac4a7a8fb11ebdb6e2ec8d77f38e77362f (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 2.6.27 is affected
  • unaffected from 0 to 2.6.27 (excl.)
  • unaffected from 5.10.253 to 5.10.* (incl.)
  • unaffected from 5.15.203 to 5.15.* (incl.)
  • unaffected from 6.1.168 to 6.1.* (incl.)
  • unaffected from 6.6.131 to 6.6.* (incl.)
  • unaffected from 6.12.80 to 6.12.* (incl.)
  • unaffected from 6.18.21 to 6.18.* (incl.)
  • unaffected from 6.19.11 to 6.19.* (incl.)
  • unaffected from 7.0 to * (incl.)

References