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CVE-2026-98794

ipvs: filter some flags received in the backup server PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: ipvs: filter some flags received in the backup server While the IPVS SYNC protocol is not secure by design we can still protect the backup server from messages that can wreak havoc. This commit addresses problems from received connection flags or their combinations. We now drop messages as follows: 1. the NO_CPORT+TEMPLATE combination allows lookups for normal connections to hit template which can break in many ways. While the master does not sync connections with NO_CPORT flag, i.e. before they are established, we still accept NO_CPORT without TEMPLATE. 2. ONE_PACKET: it is not sent by master, so we do not expect it in backup. Before now it was ignored by IP_VS_CONN_F_BACKUP_MASK for protocol v1 while protocol v0 created connections that are not hashed and dropped immediately. Better to apply the IP_VS_CONN_F_BACKUP_MASK also to the flags from v0 messages for consistency with v1.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 before d7d33c9efa9d1a2f244a1a64ec9b540b0f8975a0; affected 87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 before f4cd1db7d421e82945713a36084bb0c35b75b27e; affected 87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 before 55d033324f67a15ff56be6d38d6e87f644e0ed62; affected 87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 before 45a93111835ccfea7d969ec73588e33745fd9834; affected 87375ab47cd0ba04124c6d3fd80db5c368f5dcb6 before f96e91748f6304668fe647e686d199d7207d36f1
Linux / Linuxaffected 2.6.14; unaffected 0 before 2.6.14; unaffected 6.6.160 through 6.6.*; unaffected 6.12.113 through 6.12.*; unaffected 6.18.56 through 6.18.*; unaffected 7.2.10 through 7.2.*; unaffected 7.3 through *

CWE

No CWE identifiers supplied.

References