CVE-2026-53225

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

sctp: fix uninit-value in _sctprcvasconflookup()

_sctprcvasconflookup() in net/sctp/input.c only checks that the ASCONF chunk can hold the ADDIP header and a parameter header, then calls af->fromaddrparam(), which reads the full address (16 bytes for IPv6) trusting the parameter's declared length.

An unauthenticated peer can send a truncated trailing ASCONF chunk that declares an IPv6 address parameter but stops after the 4-byte parameter header; reached from the no-association lookup path, fromaddrparam() then reads uninitialized bytes past the parameter.

Impact: an unauthenticated SCTP peer makes the receive path read up to 16 bytes of uninitialized memory past a truncated ASCONF address parameter.

The sibling _sctprcvinitlookup() bounds parameters with sctpwalkparams(); this path open-codes the fetch and omits the bound. Verify the whole address parameter lies within the chunk before fromaddrparam() reads it, the same class of fix as commit 51e5ad549c43 ("net: sctp: fix KMSAN uninit-value in sctpinqpop").