Subject: CVE-2024-44953: scsi: ufs: core: Fix deadlock during RTC update

From: Greg Kroah-Hartman <[email-masked]>

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

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

scsi: ufs: core: Fix deadlock during RTC update

There is a deadlock when runtime suspend waits for the flush of RTC work,
and the RTC work calls ufshcd_rpm_get_sync() to wait for runtime resume.

Here is deadlock backtrace:

kworker/0:1     D 4892.876354 10 10971 4859 0x4208060 0x8 10 0 120 670730152367
ptr            f0ffff80c2e40000 0 1 0x00000001 0x000000ff 0x000000ff 0x000000ff
<ffffffee5e71ddb0> __switch_to+0x1a8/0x2d4
<ffffffee5e71e604> __schedule+0x684/0xa98
<ffffffee5e71ea60> schedule+0x48/0xc8
<ffffffee5e725f78> schedule_timeout+0x48/0x170
<ffffffee5e71fb74> do_wait_for_common+0x108/0x1b0
<ffffffee5e71efe0> wait_for_completion+0x44/0x60
<ffffffee5d6de968> __flush_work+0x39c/0x424
<ffffffee5d6decc0> __cancel_work_sync+0xd8/0x208
<ffffffee5d6dee2c> cancel_delayed_work_sync+0x14/0x28
<ffffffee5e2551b8> __ufshcd_wl_suspend+0x19c/0x480
<ffffffee5e255fb8> ufshcd_wl_runtime_suspend+0x3c/0x1d4
<ffffffee5dffd80c> scsi_runtime_suspend+0x78/0xc8
<ffffffee5df93580> __rpm_callback+0x94/0x3e0
<ffffffee5df90b0c> rpm_suspend+0x2d4/0x65c
<ffffffee5df91448> __pm_runtime_suspend+0x80/0x114
<ffffffee5dffd95c> scsi_runtime_idle+0x38/0x6c
<ffffffee5df912f4> rpm_idle+0x264/0x338
<ffffffee5df90f14> __pm_runtime_idle+0x80/0x110
<ffffffee5e24ce44> ufshcd_rtc_work+0x128/0x1e4
<ffffffee5d6e3a40> process_one_work+0x26c/0x650
<ffffffee5d6e65c8> worker_thread+0x260/0x3d8
<ffffffee5d6edec8> kthread+0x110/0x134
<ffffffee5d616b18> ret_from_fork+0x10/0x20

Skip updating RTC if RPM state is not RPM_ACTIVE.

The Linux kernel CVE team has assigned CVE-2024-44953 to this issue.

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

	Issue introduced in 6.8 with commit 6bf999e0eb41 and fixed in 6.10.5 with commit f13f1858a28c
	Issue introduced in 6.8 with commit 6bf999e0eb41 and fixed in 6.11 with commit 3911af778f20

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-2024-44953
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/ufs/core/ufshcd-priv.h
	drivers/ufs/core/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/f13f1858a28c68b7fc0d72c2008d5c1f80d2e8d5
	https://git.kernel.org/stable/c/3911af778f208e5f49d43ce739332b91e26bc48e