| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-47622: scsi: ufs: Fix a deadlock in the error handler |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47622 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.15.25 with commit 493c9e850677df8b4eda150c2364b1c1a72ed724 |
| Fixed in 5.16.11 with commit d69d98d8edf90e25e4e09930dd36dd6d09dd6768 |
| Fixed in 5.17 with commit 945c3cca05d78351bba29fa65d93834cb7934c7b |
| |
| 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-2021-47622 |
| 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 |
| drivers/scsi/ufs/ufshcd.h |
| |
| |
| 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/493c9e850677df8b4eda150c2364b1c1a72ed724 |
| https://git.kernel.org/stable/c/d69d98d8edf90e25e4e09930dd36dd6d09dd6768 |
| https://git.kernel.org/stable/c/945c3cca05d78351bba29fa65d93834cb7934c7b |
