Subject: CVE-2024-41054: scsi: ufs: core: Fix ufshcd_clear_cmd racing issue

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

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

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

scsi: ufs: core: Fix ufshcd_clear_cmd racing issue

When ufshcd_clear_cmd is racing with the completion ISR, the completed tag
of the request's mq_hctx pointer will be set to NULL by the ISR.  And
ufshcd_clear_cmd's call to ufshcd_mcq_req_to_hwq will get NULL pointer KE.
Return success when the request is completed by ISR because sq does not
need cleanup.

The racing flow is:

Thread A
ufshcd_err_handler					step 1
	ufshcd_try_to_abort_task
		ufshcd_cmd_inflight(true)		step 3
		ufshcd_clear_cmd
			...
			ufshcd_mcq_req_to_hwq
			blk_mq_unique_tag
				rq->mq_hctx->queue_num	step 5

Thread B
ufs_mtk_mcq_intr(cq complete ISR)			step 2
	scsi_done
		...
		__blk_mq_free_request
			rq->mq_hctx = NULL;		step 4

Below is KE back trace:

  ufshcd_try_to_abort_task: cmd pending in the device. tag = 6
  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000194
   pc : [0xffffffd589679bf8] blk_mq_unique_tag+0x8/0x14
   lr : [0xffffffd5862f95b4] ufshcd_mcq_sq_cleanup+0x6c/0x1cc [ufs_mediatek_mod_ise]
   Workqueue: ufs_eh_wq_0 ufshcd_err_handler [ufs_mediatek_mod_ise]
   Call trace:
    dump_backtrace+0xf8/0x148
    show_stack+0x18/0x24
    dump_stack_lvl+0x60/0x7c
    dump_stack+0x18/0x3c
    mrdump_common_die+0x24c/0x398 [mrdump]
    ipanic_die+0x20/0x34 [mrdump]
    notify_die+0x80/0xd8
    die+0x94/0x2b8
    __do_kernel_fault+0x264/0x298
    do_page_fault+0xa4/0x4b8
    do_translation_fault+0x38/0x54
    do_mem_abort+0x58/0x118
    el1_abort+0x3c/0x5c
    el1h_64_sync_handler+0x54/0x90
    el1h_64_sync+0x68/0x6c
    blk_mq_unique_tag+0x8/0x14
    ufshcd_clear_cmd+0x34/0x118 [ufs_mediatek_mod_ise]
    ufshcd_try_to_abort_task+0x2c8/0x5b4 [ufs_mediatek_mod_ise]
    ufshcd_err_handler+0xa7c/0xfa8 [ufs_mediatek_mod_ise]
    process_one_work+0x208/0x4fc
    worker_thread+0x228/0x438
    kthread+0x104/0x1d4
    ret_from_fork+0x10/0x20

The Linux kernel CVE team has assigned CVE-2024-41054 to this issue.

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

	Issue introduced in 6.5 with commit 8d7290348992 and fixed in 6.6.41 with commit bed089600833
	Issue introduced in 6.5 with commit 8d7290348992 and fixed in 6.9.10 with commit 11d81233f4eb
	Issue introduced in 6.5 with commit 8d7290348992 and fixed in 6.10 with commit 9307a998cb98

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-2024-41054
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/ufs-mcq.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/bed0896008334eeee4b4bfd7150491ca098cbf72
	https://git.kernel.org/stable/c/11d81233f4ebe6907b12c79ad7d8787aa4db0633
	https://git.kernel.org/stable/c/9307a998cb9846a2557fdca286997430bee36a2a