CVE-2026-89776 PUBLISHED

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

Assigner: Linux
Reserved: 11.09.2026 Published: 16.09.2026 Updated: 16.09.2026

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.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from f9c4bb0b245cee35ef66f75bf409c9573d934cf9 to e12c4663529699f457b2988c1dfedf4d13b3b3be (excl.)
  • affected from f9c4bb0b245cee35ef66f75bf409c9573d934cf9 to 47bfcc871576eaef6c8edab6749acd4b317306ea (excl.)
  • affected from f9c4bb0b245cee35ef66f75bf409c9573d934cf9 to a9ec10815199f9879ba080241dc555efb1daf324 (excl.)
  • affected from f9c4bb0b245cee35ef66f75bf409c9573d934cf9 to daebc7064a1b4c12c98e52c4bceede7f2fcd573c (excl.)
  • affected from f9c4bb0b245cee35ef66f75bf409c9573d934cf9 to ad32e564c62ebf5ba76dd60a22af52c69d54d17b (excl.)
  • affected from f9c4bb0b245cee35ef66f75bf409c9573d934cf9 to 984f831dda31b3a18f47454cf64989f65402879e (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 5.18 is affected
  • unaffected from 0 to 5.18 (excl.)
  • unaffected from 6.1.188 to 6.1.* (incl.)
  • unaffected from 6.6.157 to 6.6.* (incl.)
  • unaffected from 6.12.110 to 6.12.* (incl.)
  • unaffected from 6.18.52 to 6.18.* (incl.)
  • unaffected from 7.2.6 to 7.2.* (incl.)
  • unaffected from 7.3-rc1 to * (incl.)

References