CVE-2021-47622

Description

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.

CVSS Metrics

• v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 3%

Techniques & Countermeasures

• CWE-667•Improper Locking

  The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.

Affected Systems

• linux•linux

  ≥ 7252a3603015f1fd04363956f4b72a537c9f9c42, < 493c9e850677df8b4eda150c2364b1c1a72ed724 | ≥ 7252a3603015f1fd04363956f4b72a537c9f9c42, < d69d98d8edf90e25e4e09930dd36dd6d09dd6768 | ≥ 7252a3603015f1fd04363956f4b72a537c9f9c42, < 945c3cca05d78351bba29fa65d93834cb7934c7b | a8d2d45c70c7391386baf7863674f156da56a3d5 | ≥ 5.4.112, < 5.5 | 5.6

• linux•linux_kernel

  < 5.15.25 | ≥ 5.16, < 5.16.11

References (3)

• https://git.kernel.org/stable/c/493c9e850677df8b4eda150c2364b1c1a72ed724
• https://git.kernel.org/stable/c/d69d98d8edf90e25e4e09930dd36dd6d09dd6768
• https://git.kernel.org/stable/c/945c3cca05d78351bba29fa65d93834cb7934c7b