CVE-2026-93267

What the bug is

When accessing a dmah via the netlink path the only synchronization mechanism for the said dmah is rdma_restrack_get(). Currently, rdma_restrack_del() is invoked at the end of uverbs_free_dmah(), which is too late, since by that point vendor-specific resources associated with the dmah might already be freed. This can leave a short window where the dmah remains accessible through restrack, leading to a potential use-after-free. Fix this by moving the rdma_restrack_begin_del() call to the start of uverbs_free_dmah(), ensuring that the dmah is removed from restrack before its internal resources are released. This guarantees that no new users hold references to a dmah that is in the process of destruction. In addition, this change preserves the intended inverted order between create and destroy routines: resources are added to restrack at the end of successful creation, and hence shall be removed from the restrack first thing during the destruction flow, which keeps the lifecycle management consistent and predictable.

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/infiniband/core/uverbs_std_types_dmah.c

What this is

INFINIBAND SUBSYSTEMMAINTAINERS section matched on drivers/infiniband/ · linux-rdma@vger.kernel.org · Supported

Kernel module

ib_uverbs

Check it on the machine

grep -wE 'CONFIG_INFINIBAND|CONFIG_INFINIBAND_USER_ACCESS' /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 ib_uverbs

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 with an answer 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. The build rule could not be established for 2 releases, so nothing is claimed about those.

• bookworm, trixie?
• forky, sidm

?

not established - no Makefile entry for the affected file

m

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

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switches

CONFIG_INFINIBAND, CONFIG_INFINIBAND_USER_ACCESS

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

2026-09-24 (24 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.18%, higher than 7.5% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/infiniband

Upstream fixes

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

Introduced	Fixed in	Commit
6.17	6.18.52	8b22722f45a2
6.17	7.2.6	bfc119a40c04
6.17	7.3	2696626a0be5