CVE-2026-68335

CVE CVE-2026-68335EUVD EUVD-2026-55436Published 2026-08-10T12:03:11.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: rds: drop incoming messages that cross network namespace boundaries rds_find_bound() looks up the destination socket using a global rhashtable keyed solely on (addr, port, scope_id). Network namespaces are not part of the key, so a sender in netns A can deliver an incoming message (inc) to a socket that lives in a different netns B. When this happens, inc->i_conn points to an rds_connection whose c_net is netns A, but the receiving rs lives in netns B. Once the child process that created netns A exits, cleanup_net() calls rds_loop_exit_net() -> rds_loop_kill_conns() -> rds_conn_destroy(), freeing that connection. If the survivor socket in netns B still holds the inc, any subsequent dereference of inc->i_conn is a use-after-free. There are two dangerous sites in rds_clear_recv_queue(): 1. inc->i_conn->c_lcong (offset 88 of freed rds_connection, size 200) read via rds_recv_rcvbuf_delta() -- confirmed by KASAN. 2. inc->i_conn->c_trans->inc_free(inc) (function pointer at offset 80) called via rds_inc_put() when the inc refcount reaches zero -- same race window, potential call-through-freed-object primitive. The bug is reachable from unprivileged user namespaces (CLONE_NEWUSER + CLONE_NEWNET), available since Linux 3.8. Fix this by rejecting the delivery in rds_recv_incoming() when the socket returned by rds_find_bound() belongs to a different network namespace than the connection that carried the message. Use the existing rds_conn_net() / sock_net() helpers and net_eq() for the comparison.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux patch: 6.18.42; patch: 6.12.101; 4.17.19 <4.18; c809195f5523dd4d09403bbb1c9732d548aa0d1e <1e2e2d9806944fe485824d617c8b7c78116c22db; c809195f5523dd4d09403bbb1c9732d548aa0d1e <5521ae71e32a8069ed4ca6e792179dc57bc43ab2; c809195f5523dd4d09403bbb1c9732d548aa0d1e <cfb3ce07b705e486e022a2f2b1242b48f13981ff; patch: 7.1.6; patch: 6.6.148; patch: 0; 4.18; c827073c95fde388bc65fe5227f944eaf859b9f0; patch: 7.2-rc5; c809195f5523dd4d09403bbb1c9732d548aa0d1e <9591042533140dfe6608d9344806d567dcd39d02; c809195f5523dd4d09403bbb1c9732d548aa0d1e <0f8690e3869109cd5803ccb400889d20a0b54e0e

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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