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Bart Van Assche authored
Make the following changes in ufshcd_abort(): - Return FAILED instead of SUCCESS if the abort handler notices that a SCSI command has already been completed. Returning SUCCESS in this case triggers a use-after-free and may trigger a kernel crash. - Fix the code for aborting SCSI commands submitted to a WLUN. The current approach for aborting SCSI commands that have been submitted to a WLUN and that timed out is as follows: - Report to the SCSI core that the command has completed successfully. Let the block layer free any data buffers associated with the command. - Mark the command as outstanding in 'outstanding_reqs'. - If the block layer tries to reuse the tag associated with the aborted command, busy-wait until the tag is freed. This approach can result in: - Memory corruption if the controller accesses the data buffer after the block layer has freed the associated data buffers. - A race condition if ufshcd_queuecommand() or ufshcd_exec_dev_cmd() checks the bit that corresponds to an aborted command in 'outstanding_reqs' after it has been cleared and before it is reset. - High energy consumption if ufshcd_queuecommand() repeatedly returns SCSI_MLQUEUE_HOST_BUSY. Fix this by reporting to the SCSI error handler that aborting a SCSI command failed if the SCSI command was submitted to a WLUN. Link: https://lore.kernel.org/r/20210722033439.26550-15-bvanassche@acm.org Fixes: 7a7e66c6 ("scsi: ufs: Fix a race condition between ufshcd_abort() and eh_work()") Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Stanley Chu <stanley.chu@mediatek.com> Cc: Can Guo <cang@codeaurora.org> Cc: Asutosh Das <asutoshd@codeaurora.org> Cc: Avri Altman <avri.altman@wdc.com> Reviewed-by: Bean Huo <beanhuo@micron.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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