scsi: qla2xxx: Drop vport reference under lock in report ID acquisition

qla24xx_report_id_acquisition() format-1 handling takes the vport
reference under vport_slock but drops it outside the lock, after setting
vp->vp_flags and vp->dpc_flags:

	set_bit(VP_IDX_ACQUIRED, &vp->vp_flags);
	set_bit(REGISTER_FC4_NEEDED, &vp->dpc_flags);
	set_bit(REGISTER_FDMI_NEEDED, &vp->dpc_flags);

	atomic_dec(&vp->vref_count);

Neither set_bit() nor atomic_dec() imply a memory barrier, so on a weakly
ordered architecture the decrement can become visible before the flag
stores. qla24xx_deallocate_vp_id() polls vref_count under vport_slock and
unlinks the vport once it reads zero, after which qla24xx_vport_delete()
frees it via scsi_host_put(). The poller could therefore observe
vref_count == 0 early and tear the vport down while the pending vp_flags/
dpc_flags stores land on freed memory.

Drop the reference under vport_slock, as is done for the matching
increment and by every other vref_count user. The unlock release pairs
with the deallocate poller's lock acquire so the flag stores are ordered
before vref_count == 0 can be observed.

Fixes: 793cedee296f ("scsi: qla2xxx: Hold vport reference in qla24xx_report_id_acquisition()")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-dev@google.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Link: https://patch.msgid.link/20260730155838.2119230-23-njavali@marvell.com
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>

0 files changed, 0 insertions, 0 deletions