CVE-2026-72307

What the bug is

When mlxsw_sp_vrs_lpm_tree_replace() fails after replacing some VRs, the error rollback loop does not correctly revert the preceding replacements. The loop decrements the index but fails to update the vr pointer, which still points to the VR that caused the failure. As a result, the condition and the rollback call always operate on the same VR, potentially calling mlxsw_sp_vr_lpm_tree_replace() multiple times on it while never rolling back the earlier VRs. Those VRs continue to hold a reference to new_tree acquired via mlxsw_sp_lpm_tree_hold(), leaking the reference count of new_tree. Fix by reinitializing vr inside the error loop with the updated index: vr = &mlxsw_sp->router->vrs[i]; so that the loop correctly iterates over all VRs that were actually replaced.

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.

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

What this is

MELLANOX ETHERNET SWITCH DRIVERSMAINTAINERS section matched on drivers/net/ethernet/mellanox/mlxsw/ · netdev@vger.kernel.org · Supported

Kernel module

none to look for. The file would have gone into mlxsw_spectrum, and Debian does not compile it into that module, so finding mlxsw_spectrum in lsmod would say nothing about this CVE.

Check it on the machine

grep -wE 'CONFIG_ETHERNET|CONFIG_MLXSW_CORE|CONFIG_MLXSW_SPECTRUM|CONFIG_NET_VENDOR_MELLANOX' /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.

Show whether Debian builds this, per release

Debian does not build this code. In 4 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.

• bookworm, trixie, forky, sidn

n

not enabled on any flavour - this release does not build the code

Build switches

CONFIG_ETHERNET, CONFIG_MLXSW_CORE, CONFIG_MLXSW_SPECTRUM, CONFIG_NET_VENDOR_MELLANOX

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

drivers/net

Upstream fixes

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

Introduced	Fixed in	Commit
4.14	5.10.261	c2c75c45b54f
4.14	5.15.212	7203ac71d389
4.14	6.1.178	f6454a5fbf22
4.14	6.6.145	220d41bdce41
4.14	6.12.97	9e4a61856799
4.14	6.18.40	3a2b47d1b4b3
4.14	7.1.5	8adebf07b46d
4.14	7.2	21cf8dc478a4