CVE-2026-89776

Summary

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

vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributes

The VXLAN VNI filter entry policy declares the GROUP/GROUP6 address attributes as NLA_BINARY with only a maximum length, so validate_nla() accepts a payload shorter than the address. The GROUP consumer reads it with nla_get_in_addr(), an unconditional 4-byte load, so a short attribute over-reads up to 3 bytes of uninitialised slab data, which are stored into remote_ip and echoed back via RTM_GETTUNNEL, disclosing kernel memory.

Switch both entries to NLA_POLICY_EXACT_LEN() so the validator rejects any GROUP/GROUP6 that is not exactly 4 / 16 bytes; a valid address is always sent at full width.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxf9c4bb0b245cee35ef66f75bf409c9573d934cf9 < e12c4663529699f457b2988c1dfedf4d13b3b3beaffected
LinuxLinuxf9c4bb0b245cee35ef66f75bf409c9573d934cf9 < 47bfcc871576eaef6c8edab6749acd4b317306eaaffected
LinuxLinuxf9c4bb0b245cee35ef66f75bf409c9573d934cf9 < a9ec10815199f9879ba080241dc555efb1daf324affected
LinuxLinuxf9c4bb0b245cee35ef66f75bf409c9573d934cf9 < daebc7064a1b4c12c98e52c4bceede7f2fcd573caffected
LinuxLinuxf9c4bb0b245cee35ef66f75bf409c9573d934cf9 < ad32e564c62ebf5ba76dd60a22af52c69d54d17baffected
LinuxLinuxf9c4bb0b245cee35ef66f75bf409c9573d934cf9 < 984f831dda31b3a18f47454cf64989f65402879eaffected
LinuxLinux5.18affected
LinuxLinux0 < 5.18unaffected
LinuxLinux6.1.188 <= 6.1.*unaffected
LinuxLinux6.6.157 <= 6.6.*unaffected
LinuxLinux6.12.110 <= 6.12.*unaffected
LinuxLinux6.18.52 <= 6.18.*unaffected
LinuxLinux7.2.6 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References