CVE-2026-68139

What the bug is

After PCIe DPC recovery, mlx5 reloads the affected functions and replays multiport affiliation events. In the reported failure, the first relevant device error was: pcieport 0000:10:01.1: DPC: containment event pcieport 0000:10:01.1: PCIe Bus Error: severity=Uncorrected (Fatal) pcieport 0000:10:01.1: [ 5] SDES (First) mlx5 recovered the PCI functions and resumed 0000:11:00.1. During that resume, RDMA multiport binding replayed MLX5_DRIVER_EVENT_AFFILIATION_DONE and mlx5e sent MPV_DEVCOM_MASTER_UP. The host then panicked with: BUG: kernel NULL pointer dereference, address: 0000000000000010 RIP: mlx5_devcom_comp_set_ready+0x5/0x40 [mlx5_core] RDI: 0000000000000000 Call trace included: mlx5_devcom_comp_set_ready mlx5e_devcom_event_mpv mlx5_devcom_send_event mlx5_ib_bind_slave_port mlx5r_mp_probe mlx5_pci_resume MPV devcom registration publishes mlx5e private data to the component peer list before mlx5e_devcom_init_mpv() stores the returned component device in priv->devcom. A concurrent master-up event can therefore reach a peer whose private data is visible but whose priv->devcom backpointer is still NULL. MPV_DEVCOM_MASTER_UP already carries the sender/master mlx5e private data as event_data. The ready bit is stored on the shared devcom component, not on an individual peer. Use the sender devcom when marking the MPV component ready. This preserves the readiness transition while avoiding a NULL dereference of the peer devcom pointer during affiliation replay after PCI error recovery.

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/mlx5/core/en_main.c

What this is

MELLANOX ETHERNET DRIVER (mlx5e)MAINTAINERS section matched on drivers/net/ethernet/mellanox/mlx5/core/en_* · netdev@vger.kernel.org · Maintained

Kernel module

mlx5_core

Check it on the machine

grep -wE 'CONFIG_ETHERNET|CONFIG_MLX5_CORE|CONFIG_MLX5_CORE_EN|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.

lsmod | grep -w mlx5_core

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, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookwormm
• trixieMnot built on armel/rpi
• forky, sid, bookworm · linux-6.12m

m

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

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_ETHERNET, CONFIG_MLX5_CORE, CONFIG_MLX5_CORE_EN, 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

2026-08-10 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.18%, higher than 6.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

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
6.7	6.12.101	c698b2735613
6.7	6.18.42	40f9a124ebbe
6.7	7.1.6	a60c81f168c9
6.7	7.2	e32649b4bad9

Debian advisories