• Nicholas Bellinger's avatar
    target: Fix COMPARE_AND_WRITE ref leak for non GOOD status · 69030974
    Nicholas Bellinger authored
    commit 9b2792c3 upstream.
    
    This patch addresses a long standing bug where the commit phase
    of COMPARE_AND_WRITE would result in a se_cmd->cmd_kref reference
    leak if se_cmd->scsi_status returned non SAM_STAT_GOOD.
    
    This would manifest first as a lost SCSI response, and eventual
    hung task during fabric driver logout or re-login, as existing
    shutdown logic waited for the COMPARE_AND_WRITE se_cmd->cmd_kref
    to reach zero.
    
    To address this bug, compare_and_write_post() has been changed
    to drop the incorrect !cmd->scsi_status conditional that was
    preventing *post_ret = 1 for being set during non SAM_STAT_GOOD
    status.
    
    This patch has been tested with SAM_STAT_CHECK_CONDITION status
    from normal target_complete_cmd() callback path, as well as the
    incoming __target_execute_cmd() submission failure path when
    se_cmd->execute_cmd() returns non zero status.
    Reported-by: default avatarDonald White <dew@datera.io>
    Cc: Donald White <dew@datera.io>
    Tested-by: default avatarGary Guo <ghg@datera.io>
    Cc: Gary Guo <ghg@datera.io>
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
    Signed-off-by: default avatarBen Hutchings <ben@decadent.org.uk>
    69030974
target_core_sbc.c 35.6 KB