CVE-2025-21993

Summary

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

iscsi_ibft: Fix UBSAN shift-out-of-bounds warning in ibft_attr_show_nic()

When performing an iSCSI boot using IPv6, iscsistart still reads the /sys/firmware/ibft/ethernetX/subnet-mask entry. Since the IPv6 prefix length is 64, this causes the shift exponent to become negative, triggering a UBSAN warning. As the concept of a subnet mask does not apply to IPv6, the value is set to ~0 to suppress the warning message.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux138fe4e069798d9aa948a5402ff15e58f483ee4e < a858cd58dea06cf85b142673deea8c5d87f11e70affected
LinuxLinux138fe4e069798d9aa948a5402ff15e58f483ee4e < f763c82db8166e28f45b7cc4a5398a7859665940affected
LinuxLinux138fe4e069798d9aa948a5402ff15e58f483ee4e < b388e185bfad32bfed6a97a6817f74ca00a4318faffected
LinuxLinux138fe4e069798d9aa948a5402ff15e58f483ee4e < 9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1caffected
LinuxLinux138fe4e069798d9aa948a5402ff15e58f483ee4e < 2d1eef248107bdf3d5a69d0fde04c30a79a7bf5daffected
LinuxLinux138fe4e069798d9aa948a5402ff15e58f483ee4e < b253660fac5e0e9080d2c95e3a029e1898d49afbaffected
LinuxLinux138fe4e069798d9aa948a5402ff15e58f483ee4e < c1c6e527470e5eab0b2d57bd073530fbace39eabaffected
LinuxLinux138fe4e069798d9aa948a5402ff15e58f483ee4e < 07e0d99a2f701123ad3104c0f1a1e66bce74d6e5affected
LinuxLinux2.6.26affected
LinuxLinux0 < 2.6.26unaffected
LinuxLinux5.4.292 <= 5.4.*unaffected
LinuxLinux5.10.236 <= 5.10.*unaffected
LinuxLinux5.15.180 <= 5.15.*unaffected
LinuxLinux6.1.132 <= 6.1.*unaffected
LinuxLinux6.6.84 <= 6.6.*unaffected
LinuxLinux6.12.20 <= 6.12.*unaffected
LinuxLinux6.13.8 <= 6.13.*unaffected
LinuxLinux6.14 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References