CVE-2026-31534: smb: client: let send_done handle a completion without IB_SEND_SIGNALED

CVE-2026-31534: smb: client: let send_done handle a completion without IB_SEND_SIGNALED

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@kernel.org>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

smb: client: let send_done handle a completion without IB_SEND_SIGNALED

With smbdirect_send_batch processing we likely have requests without
IB_SEND_SIGNALED, which will be destroyed in the final request
that has IB_SEND_SIGNALED set.

If the connection is broken all requests are signaled
even without explicit IB_SEND_SIGNALED.

The Linux kernel CVE team has assigned CVE-2026-31534 to this issue.


Affected and fixed versions
===========================

	Fixed in 6.18.11 with commit 16c8be3d55441287ddd334e25df4cc376450dec9
	Fixed in 6.19.1 with commit 86d9742c3f7ed7eba677517c80b4597822750e65
	Fixed in 7.0 with commit cf74fcdc43b322b6188a0750b5ee79e38be6d078

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-31534
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	fs/smb/client/smbdirect.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/16c8be3d55441287ddd334e25df4cc376450dec9
	https://git.kernel.org/stable/c/86d9742c3f7ed7eba677517c80b4597822750e65
	https://git.kernel.org/stable/c/cf74fcdc43b322b6188a0750b5ee79e38be6d078