Bug 2492846 (CVE-2026-53225)

Summary: CVE-2026-53225 kernel: sctp: fix uninit-value in __sctp_rcv_asconf_lookup()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation. An unauthenticated remote attacker can exploit this vulnerability by sending a specially crafted, truncated ASCONF (Address Configuration) chunk. This can cause the system to read up to 16 bytes of uninitialized memory, potentially leading to information disclosure or memory corruption.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-06-25 10:08:47 UTC
In the Linux kernel, the following vulnerability has been resolved:

sctp: fix uninit-value in __sctp_rcv_asconf_lookup()

__sctp_rcv_asconf_lookup() in net/sctp/input.c only checks that the ASCONF
chunk can hold the ADDIP header and a parameter header, then calls
af->from_addr_param(), 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, from_addr_param() 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 __sctp_rcv_init_lookup() bounds parameters with
sctp_walk_params(); this path open-codes the fetch and omits the bound.
Verify the whole address parameter lies within the chunk before
from_addr_param() reads it, the same class of fix as commit 51e5ad549c43
("net: sctp: fix KMSAN uninit-value in sctp_inq_pop").

Comment 1 Mauro Matteo Cascella 2026-06-25 16:42:38 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062507-CVE-2026-53225-52de@gregkh/T