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Mike Christie 0b4ea5b72b scsi: qedi: Fix ABBA deadlock in qedi_process_tmf_resp() and qedi_process_cmd_cleanup_resp()

commit f10f582d28220f50099d3f561116256267821429 upstream.

This fixes a deadlock added with commit b40f3894e39e ("scsi: qedi: Complete
TMF works before disconnect")

Bug description from Jia-Ju Bai:

qedi_process_tmf_resp()
  spin_lock(&session->back_lock); --> Line 201 (Lock A)
  spin_lock(&qedi_conn->tmf_work_lock); --> Line 230 (Lock B)

qedi_process_cmd_cleanup_resp()
  spin_lock_bh(&qedi_conn->tmf_work_lock); --> Line 752 (Lock B)
  spin_lock_bh(&conn->session->back_lock); --> Line 784 (Lock A)

When qedi_process_tmf_resp() and qedi_process_cmd_cleanup_resp() are
concurrently executed, the deadlock can occur.

This patch fixes the deadlock by not holding the tmf_work_lock in
qedi_process_cmd_cleanup_resp while holding the back_lock. The
tmf_work_lock is only needed while we remove the tmf_work from the
work_list.

Link: https://lore.kernel.org/r/20220208185448.6206-1-michael.christie@oracle.com
Fixes: b40f3894e39e ("scsi: qedi: Complete TMF works before disconnect")
Cc: Manish Rangankar <mrangankar@marvell.com>
Cc: Nilesh Javali <njavali@marvell.com>
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2022-02-23 12:03:22 +01:00

Kconfig

treewide: replace '---help---' in Kconfig files with 'help'

2020-06-14 01:57:21 +09:00

Makefile

…

qedi_dbg.c

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 440

2019-06-05 17:37:17 +02:00

qedi_dbg.h

scsi: Fix various misspellings of "connect"

2019-10-24 21:22:32 -04:00