In the Linux kernel, the following vulnerability has been resolved: scsi: core: ufs: Fix a hang in the error handler ufshcd_err_handling_prepare() calls ufshcd_rpm_get_sync(). The latter function can only succeed if UFSHCD_EH_IN_PROGRESS is not set because resuming involves submitting a SCSI command and ufshcd_queuecommand() returns SCSI_MLQUEUE_HOST_BUSY if UFSHCD_EH_IN_PROGRESS is set. Fix this hang by setting UFSHCD_EH_IN_PROGRESS after ufshcd_rpm_get_sync() has been called instead of before. Backtrace: __switch_to+0x174/0x338 __schedule+0x600/0x9e4 schedule+0x7c/0xe8 schedule_timeout+0xa4/0x1c8 io_schedule_timeout+0x48/0x70 wait_for_common_io+0xa8/0x160 //waiting on START_STOP wait_for_completion_io_timeout+0x10/0x20 blk_execute_rq+0xe4/0x1e4 scsi_execute_cmd+0x108/0x244 ufshcd_set_dev_pwr_mode+0xe8/0x250 __ufshcd_wl_resume+0x94/0x354 ufshcd_wl_runtime_resume+0x3c/0x174 scsi_runtime_resume+0x64/0xa4 rpm_resume+0x15c/0xa1c __pm_runtime_resume+0x4c/0x90 // Runtime resume ongoing ufshcd_err_handler+0x1a0/0xd08 process_one_work+0x174/0x808 worker_thread+0x15c/0x490 kthread+0xf4/0x1ec ret_from_fork+0x10/0x20 [ bvanassche: rewrote patch description ]
scsi: core: ufs: Fix a hang in the error handler