CVE-2021-47188: scsi: ufs: core: Improve SCSI abort handling

CVE-2021-47188: scsi: ufs: core: Improve SCSI abort handling

[Greg Kroah-Hartman]

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

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

scsi: ufs: core: Improve SCSI abort handling

The following has been observed on a test setup:

WARNING: CPU: 4 PID: 250 at drivers/scsi/ufs/ufshcd.c:2737 ufshcd_queuecommand+0x468/0x65c
Call trace:
 ufshcd_queuecommand+0x468/0x65c
 scsi_send_eh_cmnd+0x224/0x6a0
 scsi_eh_test_devices+0x248/0x418
 scsi_eh_ready_devs+0xc34/0xe58
 scsi_error_handler+0x204/0x80c
 kthread+0x150/0x1b4
 ret_from_fork+0x10/0x30

That warning is triggered by the following statement:

	WARN_ON(lrbp->cmd);

Fix this warning by clearing lrbp->cmd from the abort handler.

The Linux kernel CVE team has assigned CVE-2021-47188 to this issue.


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

	Issue introduced in 3.4 with commit 7a3e97b0dc4b and fixed in 5.15.5 with commit c36baca06efa
	Issue introduced in 3.4 with commit 7a3e97b0dc4b and fixed in 5.16 with commit 3ff1f6b6ba6f

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-2021-47188
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:
	drivers/scsi/ufs/ufshcd.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/c36baca06efa833adaefba61f45fefdc49b6d070
	https://git.kernel.org/stable/c/3ff1f6b6ba6f97f50862aa50e79959cc8ddc2566