CVE-2025-21993

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

State: Published
Severity: 7.1 High
Published: Apr 2, 2025
Updated: May 11, 2026
Reserved: Dec 29, 2024

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.1 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H	CISA-ADP

Weaknesses

CWE-125 Out-of-bounds Read

Affected Products

Product	Versions
LinuxLinux	138fe4e069798d9aa948a5402ff15e58f483ee4e to before a858cd58dea06cf85b142673deea8c5d87f11e70Affected 138fe4e069798d9aa948a5402ff15e58f483ee4e to before f763c82db8166e28f45b7cc4a5398a7859665940Affected 138fe4e069798d9aa948a5402ff15e58f483ee4e to before b388e185bfad32bfed6a97a6817f74ca00a4318fAffected 138fe4e069798d9aa948a5402ff15e58f483ee4e to before 9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1cAffected 138fe4e069798d9aa948a5402ff15e58f483ee4e to before 2d1eef248107bdf3d5a69d0fde04c30a79a7bf5dAffected 138fe4e069798d9aa948a5402ff15e58f483ee4e to before b253660fac5e0e9080d2c95e3a029e1898d49afbAffected 138fe4e069798d9aa948a5402ff15e58f483ee4e to before c1c6e527470e5eab0b2d57bd073530fbace39eabAffected 138fe4e069798d9aa948a5402ff15e58f483ee4e to before 07e0d99a2f701123ad3104c0f1a1e66bce74d6e5Affected
LinuxLinux	2.6.26Affected before 2.6.26Not affected 5.4.292 through 5.4.Not affected 5.10.236 through 5.10.Not affected 5.15.180 through 5.15.Not affected 6.1.132 through 6.1.Not affected 6.6.84 through 6.6.Not affected 6.12.20 through 6.12.Not affected 6.13.8 through 6.13.*Not affected 6.14 and laterNot affected

Product

Versions

LinuxLinux

138fe4e069798d9aa948a5402ff15e58f483ee4e to before a858cd58dea06cf85b142673deea8c5d87f11e70Affected
138fe4e069798d9aa948a5402ff15e58f483ee4e to before f763c82db8166e28f45b7cc4a5398a7859665940Affected
138fe4e069798d9aa948a5402ff15e58f483ee4e to before b388e185bfad32bfed6a97a6817f74ca00a4318fAffected
138fe4e069798d9aa948a5402ff15e58f483ee4e to before 9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1cAffected
138fe4e069798d9aa948a5402ff15e58f483ee4e to before 2d1eef248107bdf3d5a69d0fde04c30a79a7bf5dAffected
138fe4e069798d9aa948a5402ff15e58f483ee4e to before b253660fac5e0e9080d2c95e3a029e1898d49afbAffected
138fe4e069798d9aa948a5402ff15e58f483ee4e to before c1c6e527470e5eab0b2d57bd073530fbace39eabAffected
138fe4e069798d9aa948a5402ff15e58f483ee4e to before 07e0d99a2f701123ad3104c0f1a1e66bce74d6e5Affected

LinuxLinux

2.6.26Affected
before 2.6.26Not affected
5.4.292 through 5.4.*Not affected
5.10.236 through 5.10.*Not affected
5.15.180 through 5.15.*Not affected
6.1.132 through 6.1.*Not affected
6.6.84 through 6.6.*Not affected
6.12.20 through 6.12.*Not affected
6.13.8 through 6.13.*Not affected
6.14 and laterNot affected

References

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