Patch "scsi: pm80xx: Set phy->enable_completion only when we wait for it" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    scsi: pm80xx: Set phy->enable_completion only when we wait for it

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     scsi-pm80xx-set-phy-enable_completion-only-when-we-w.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 48f5d81886dd65cb8805e11ba946bf45a4dca75f
Author: Igor Pylypiv <ipylypiv@xxxxxxxxxx>
Date:   Thu Jun 27 15:59:23 2024 +0000

    scsi: pm80xx: Set phy->enable_completion only when we wait for it
    
    [ Upstream commit e4f949ef1516c0d74745ee54a0f4882c1f6c7aea ]
    
    pm8001_phy_control() populates the enable_completion pointer with a stack
    address, sends a PHY_LINK_RESET / PHY_HARD_RESET, waits 300 ms, and
    returns. The problem arises when a phy control response comes late.  After
    300 ms the pm8001_phy_control() function returns and the passed
    enable_completion stack address is no longer valid. Late phy control
    response invokes complete() on a dangling enable_completion pointer which
    leads to a kernel crash.
    
    Signed-off-by: Igor Pylypiv <ipylypiv@xxxxxxxxxx>
    Signed-off-by: Terrence Adams <tadamsjr@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240627155924.2361370-2-tadamsjr@xxxxxxxxxx
    Acked-by: Jack Wang <jinpu.wang@xxxxxxxxx>
    Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index a5a31dfa4512..ee2da8e49d4c 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -166,7 +166,6 @@ int pm8001_phy_control(struct asd_sas_phy *sas_phy, enum phy_func func,
 	unsigned long flags;
 	pm8001_ha = sas_phy->ha->lldd_ha;
 	phy = &pm8001_ha->phy[phy_id];
-	pm8001_ha->phy[phy_id].enable_completion = &completion;
 
 	if (PM8001_CHIP_DISP->fatal_errors(pm8001_ha)) {
 		/*
@@ -190,6 +189,7 @@ int pm8001_phy_control(struct asd_sas_phy *sas_phy, enum phy_func func,
 				rates->maximum_linkrate;
 		}
 		if (pm8001_ha->phy[phy_id].phy_state ==  PHY_LINK_DISABLE) {
+			pm8001_ha->phy[phy_id].enable_completion = &completion;
 			PM8001_CHIP_DISP->phy_start_req(pm8001_ha, phy_id);
 			wait_for_completion(&completion);
 		}
@@ -198,6 +198,7 @@ int pm8001_phy_control(struct asd_sas_phy *sas_phy, enum phy_func func,
 		break;
 	case PHY_FUNC_HARD_RESET:
 		if (pm8001_ha->phy[phy_id].phy_state == PHY_LINK_DISABLE) {
+			pm8001_ha->phy[phy_id].enable_completion = &completion;
 			PM8001_CHIP_DISP->phy_start_req(pm8001_ha, phy_id);
 			wait_for_completion(&completion);
 		}
@@ -206,6 +207,7 @@ int pm8001_phy_control(struct asd_sas_phy *sas_phy, enum phy_func func,
 		break;
 	case PHY_FUNC_LINK_RESET:
 		if (pm8001_ha->phy[phy_id].phy_state == PHY_LINK_DISABLE) {
+			pm8001_ha->phy[phy_id].enable_completion = &completion;
 			PM8001_CHIP_DISP->phy_start_req(pm8001_ha, phy_id);
 			wait_for_completion(&completion);
 		}