[BUG] scsi/qla2xxx: a possible sleep-in-atomic bug in qlt_get_tag

From: Jia-Ju Bai
Date: Tue Dec 12 2017 - 22:18:24 EST


The driver may sleep under a spinlock.
The function call paths are:
qlt_handle_abts_recv_work (acquire the spinlock)
qlt_response_pkt_all_vps
qlt_response_pkt
qlt_handle_cmd_for_atio
qlt_get_tag
percpu_ida_alloc --> may sleep

qla82xx_msix_rsp_q (acquire the spinlock)
qla24xx_process_response_queue
qlt_handle_abts_recv
qlt_response_pkt_all_vps
qlt_response_pkt
qlt_handle_cmd_for_atio
qlt_get_tag
percpu_ida_alloc --> may sleep-in-atomic

qla24xx_intr_handler (acquire the spinlock)
qla24xx_process_response_queue
qlt_handle_abts_recv
qlt_response_pkt
qlt_handle_cmd_for_atio
qlt_get_tag
percpu_ida_alloc --> may sleep

I do not find a good way to fix it, so I only report.
This possible bug is found by my static analysis tool (DSAC) and checked by my code review.


Thanks,
Jia-Ju Bai