CVEvulnerability
CVE-2026-89776
- Status
- Received
- Published
- 2026-09-16
- Last modified
- 2026-10-19
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Description
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.
References
- https://git.kernel.org/stable/c/47bfcc871576eaef6c8edab6749acd4b317306ea git.kernel.org
- https://git.kernel.org/stable/c/984f831dda31b3a18f47454cf64989f65402879e git.kernel.org
- https://git.kernel.org/stable/c/a9ec10815199f9879ba080241dc555efb1daf324 git.kernel.org
- https://git.kernel.org/stable/c/ad32e564c62ebf5ba76dd60a22af52c69d54d17b git.kernel.org
- https://git.kernel.org/stable/c/daebc7064a1b4c12c98e52c4bceede7f2fcd573c git.kernel.org
- https://git.kernel.org/stable/c/e12c4663529699f457b2988c1dfedf4d13b3b3be git.kernel.org