CVE-2026-72447

What the bug is

SCTP_DIAG endpoint dumping was traversing endpoint address lists without holding lock_sock(), while those lists could change concurrently via socket operations (e.g., bindx changes). This creates a race where nla_reserve() counts addresses under RCU protection, but the subsequent copy may see fewer entries, potentially leaking uninitialized memory to userspace. Fix this by: - Taking a reference on each endpoint during hash traversal - Moving socket operations (lock_sock()) outside read_lock_bh() - Serializing address list access during dump - Reworking sctp_for_each_endpoint() to support restart-based traversal with (net, pos) tracking Also: - Add WARN_ON_ONCE() for inconsistent address counts - Fix idiag_states filtering for LISTEN vs association cases - Skip dumping endpoints being freed (ep->base.dead) - Move dump position tracking into iterator, removing cb->args[4] and its comment for sctp_ep_dump()., - Update the comment for cb->args[4] and remove the comment for unused cb->args[5] for sctp_sock_dump(). Note: traversal is restart-based and may re-scan buckets multiple times, but this is acceptable due to small bucket sizes and required to support sleeping-safe callbacks. This issue was reported by Nico Yip (@_cyeaa_) working with TrendAI Zero Day Initiative.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

include/net/sctp/sctp.h
net/sctp/diag.c
net/sctp/socket.c

What this is

SCTP PROTOCOLMAINTAINERS section matched on include/net/sctp/ · linux-sctp@vger.kernel.org · Maintained

Kernel module

sctp_diag

Check it on the machine

grep -wE 'CONFIG_INET_SCTP_DIAG|CONFIG_IP_SCTP' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w sctp_diag

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this as a loadable module. Every release below compiles it as a module on every flavour, so whether the code is in the running kernel depends on whether that module is loaded.

• bookworm, trixie, forky, sidm

m

a loadable module on every flavour - check lsmod, can be blacklisted

Build switches

CONFIG_INET_SCTP_DIAG, CONFIG_IP_SCTP

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-08-15 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.22%, higher than 11.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

include/net

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
4.7	5.10.261	f98c294a9369
4.7	5.15.212	8b38e3dcfde3
4.7	6.1.178	ec3c2d59a192
4.7	6.6.145	722576aba0a6
4.7	6.12.97	abe7f8828e6a
4.7	6.18.40	207bb4ce8fe7
4.7	7.1.5	f09a245f33e5
4.7	7.2	7d8297e26b4e