SB20260720254 - Out-of-bounds write in Linux kernel ethtool

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-63987)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to an out-of-bounds write in ethnl_update_profile() in the ethtool coalesce handling code when processing a user-controlled Netlink nested attribute list for ETHTOOL_A_PROFILE_IRQ_MODERATION. A local user can send a specially crafted Netlink request with excessive nested profile entries to cause a denial of service.

The number of nested entries is entirely user-controlled, while the destination buffer is allocated for only NET_DIM_PARAMS_NUM_PROFILES entries.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0c02c190bcd9822477038ff2cee10ea584ac1b1d
• https://git.kernel.org/stable/c/6205f7166d2dd14a017a5802c81e5bd1421a8635
• https://git.kernel.org/stable/c/7281b096b072f6c6e30420e3467d738f2e4c4b57
• https://git.kernel.org/stable/c/d4c9cc7c47781c6f4fa29d80a1193a8bcd1525bc