CVE-2021-47622 scsi: ufs: Fix a deadlock in the error handler

2024-07-1611:29:38

Linux

www.cve.org

linux kernel

vulnerability

scsi ufs

deadlock

error handler

ufshcd_err_handler

EPSS

Percentile

5.0%

JSON

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

scsi: ufs: Fix a deadlock in the error handler

The following deadlock has been observed on a test setup:

All tags allocated
The SCSI error handler calls ufshcd_eh_host_reset_handler()
ufshcd_eh_host_reset_handler() queues work that calls
ufshcd_err_handler()
ufshcd_err_handler() locks up as follows:

Workqueue: ufs_eh_wq_0 ufshcd_err_handler.cfi_jt
Call trace:
__switch_to+0x298/0x5d8
__schedule+0x6cc/0xa94
schedule+0x12c/0x298
blk_mq_get_tag+0x210/0x480
__blk_mq_alloc_request+0x1c8/0x284
blk_get_request+0x74/0x134
ufshcd_exec_dev_cmd+0x68/0x640
ufshcd_verify_dev_init+0x68/0x35c
ufshcd_probe_hba+0x12c/0x1cb8
ufshcd_host_reset_and_restore+0x88/0x254
ufshcd_reset_and_restore+0xd0/0x354
ufshcd_err_handler+0x408/0xc58
process_one_work+0x24c/0x66c
worker_thread+0x3e8/0xa4c
kthread+0x150/0x1b4
ret_from_fork+0x10/0x30

Fix this lockup by making ufshcd_exec_dev_cmd() allocate a reserved
request.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/scsi/ufs/ufshcd.c",
      "drivers/scsi/ufs/ufshcd.h"
    ],
    "versions": [
      {
        "version": "1da177e4c3f4",
        "lessThan": "493c9e850677",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "d69d98d8edf9",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "1da177e4c3f4",
        "lessThan": "945c3cca05d7",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/scsi/ufs/ufshcd.c",
      "drivers/scsi/ufs/ufshcd.h"
    ],
    "versions": [
      {
        "version": "5.15.25",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.16.11",
        "lessThanOrEqual": "5.16.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.17",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]