netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator When batching multiple NFLOG messages (inst->qlen > 1), __nfulnl_send() appends an NLMSG_DONE terminator with sizeof(struct nfgenmsg) payload via nlmsg_put(), but never initializes the nfgenmsg bytes. The nlmsg_put() helper only zeroes alignment padding after the payload, not the payload itself, so four bytes of stale kernel heap data are leaked to userspace in the NLMSG_DONE message body. Use nfnl_msg_put() to build the NLMSG_DONE terminator, which initializes the nfgenmsg payload via nfnl_fill_hdr(), consistent with how __build_packet_message() already constructs NFULNL_MSG_PACKET headers.

Timeline

1. May 6, 2026, 7:40 AM UTCCVE published
2. Oct 15, 2026, 1:19 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 · fixed in 296f18e1c3a87c915a92ed27832d5040a22d1072; From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 · fixed in 9e2182865de781c41ab16b7985e9d26dcefea867; From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 · fixed in 57cc509d82b46150a11dcecc8b25eaa177eda34d; From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 · fixed in 368c22aea490f6f50df831b4f9e3623787686c5b; From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 · fixed in d1399632ba255d2e02c757af5d9f5d9279ce168c; From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 · fixed in d552bcfca323d175664d7444989b04f55666978a; From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 · fixed in 15d209bccf9273b4a8b4e579ba0e92d065b6ec8c; From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 · fixed in 1f3083aec8836213da441270cdb1ab612dd82cf4

• Linux Linux

  2.6.23

• KernelLinux

  From 2.6.23 · fixed in 5.10.258; From 5.11.0 · fixed in 5.15.209; From 5.16.0 · fixed in 6.1.175; From 6.2.0 · fixed in 6.6.136; From 6.7.0 · fixed in 6.12.83; From 6.13.0 · fixed in 6.18.24; From 6.19.0 · fixed in 6.19.14

References 8