CVE-2026-80733 PUBLISHED

net: remove WARN_ON_ONCE() from sk_mc_loop()

Assigner: Linux
Reserved: 26.08.2026 Published: 03.09.2026 Updated: 03.09.2026

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

net: remove WARN_ON_ONCE() from sk_mc_loop()

sk_mc_loop() can be called for sockets that are neither AF_INET nor AF_INET6 (e.g. AF_PACKET sockets when sending packets via raw/packet socket over virtual devices such as VRF or ipvlan).

In such cases, sk_family is not AF_INET/AF_INET6 and sk_mc_loop() falls through the switch statement and triggers WARN_ON_ONCE(1).

Non-INET sockets do not support IP_MULTICAST_LOOP or IPV6_MULTICAST_LOOP options, so loopback should default to true without generating a warning.

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 to 97133c4d42654578fab95abe47359ebe784dde18 (excl.)
  • affected from f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 to f625c742b33dc137c209dd13d1c5f12b1c18d71c (excl.)
  • affected from f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 to ad7fa2f411cb30f63d6725f111be134064cdb718 (excl.)
  • affected from f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 to d2adc4e80b29e58b5162ae09f0f657a215806c8c (excl.)
  • affected from f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 to ad7dbb1d14b1b4406eca8ef9478e8de312ba0cfe (excl.)
  • affected from f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 to c8f256dc849205ccb2bd78bd99a3497b972b44e0 (excl.)
  • affected from f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 to 0d75f2c1d0764efa756ad9c1e078d8c09ea8fc1f (excl.)
  • affected from f60e5990d9c1424af9dbca60a23ba2a1c7c1ce90 to b8a39a09ae4eaae04309e1e38ed6a1101d967496 (excl.)
  • Version c91f81773cd4bbebfe744e9ab30a7ce093f9b930 is affected
  • Version c8c30b2b17f2133e953850c547e3902c3a3d80e2 is affected
  • Version 3fe207e4637a2e792c46a08666aa722f77d7f8f7 is affected
  • affected from 3.14.40 to 3.15 (excl.)
  • affected from 3.18.13 to 3.19 (excl.)
  • affected from 3.19.6 to 3.20 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 4.0 is affected
  • unaffected from 0 to 4.0 (excl.)
  • unaffected from 5.10.265 to 5.10.* (incl.)
  • unaffected from 5.15.216 to 5.15.* (incl.)
  • unaffected from 6.1.183 to 6.1.* (incl.)
  • unaffected from 6.6.152 to 6.6.* (incl.)
  • unaffected from 6.12.104 to 6.12.* (incl.)
  • unaffected from 6.18.45 to 6.18.* (incl.)
  • unaffected from 7.1.9 to 7.1.* (incl.)
  • unaffected from 7.2 to * (incl.)

References