CVE-2025-21993

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.

The following products are affected by CVE-2025-21993 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2025-21993.

URL	Resource
https://git.kernel.org/stable/c/07e0d99a2f701123ad3104c0f1a1e66bce74d6e5
https://git.kernel.org/stable/c/2d1eef248107bdf3d5a69d0fde04c30a79a7bf5d
https://git.kernel.org/stable/c/9bfa80c8aa4e06dff55a953c3fffbfc68a3a3b1c
https://git.kernel.org/stable/c/a858cd58dea06cf85b142673deea8c5d87f11e70
https://git.kernel.org/stable/c/b253660fac5e0e9080d2c95e3a029e1898d49afb
https://git.kernel.org/stable/c/b388e185bfad32bfed6a97a6817f74ca00a4318f
https://git.kernel.org/stable/c/c1c6e527470e5eab0b2d57bd073530fbace39eab
https://git.kernel.org/stable/c/f763c82db8166e28f45b7cc4a5398a7859665940
https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
https://lore.kernel.org/linux-cve-announce/2025040257-CVE-2025-21993-54d1@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2025-21993
https://www.cve.org/CVERecord?id=CVE-2025-21993