linux-kernel - [PATCH v1 2/5] bus: mhi: core: Handle disable transitions in state worker

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1589248989-23824-3-git-send-email-hemantk@codeaurora.org>
Date:   Mon, 11 May 2020 19:03:06 -0700
From:   Hemant Kumar <hemantk@...eaurora.org>
To:     manivannan.sadhasivam@...aro.org
Cc:     linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        jhugo@...eaurora.org, bbhatt@...eaurora.org,
        Hemant Kumar <hemantk@...eaurora.org>
Subject: [PATCH v1 2/5] bus: mhi: core: Handle disable transitions in state worker

Mission mode transition is handled by state worker thread but
power off is not. There is a possibility while mission mode
transition is in progress which calls MHI client driver probe,
power off is issued by MHI controller. This results into client
driver probe and remove running in parallel and causes use after
free situation. By queuing disable transition work when mission
mode is in progress prevents the race condition.

Signed-off-by: Hemant Kumar <hemantk@...eaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@...eaurora.org>
---
 drivers/bus/mhi/core/init.c     |  1 +
 drivers/bus/mhi/core/internal.h |  1 +
 drivers/bus/mhi/core/pm.c       | 11 ++++++++++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 3a853c5..12207cc 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -35,6 +35,7 @@
 	[DEV_ST_TRANSITION_SBL] = "SBL",
 	[DEV_ST_TRANSITION_MISSION_MODE] = "MISSION_MODE",
 	[DEV_ST_TRANSITION_SYS_ERR] = "SYS_ERR",
+	[DEV_ST_TRANSITION_DISABLE] = "DISABLE",
 };
 
 const char * const mhi_state_str[MHI_STATE_MAX] = {
diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index f01283b..b1f640b 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -387,6 +387,7 @@ enum dev_st_transition {
 	DEV_ST_TRANSITION_SBL,
 	DEV_ST_TRANSITION_MISSION_MODE,
 	DEV_ST_TRANSITION_SYS_ERR,
+	DEV_ST_TRANSITION_DISABLE,
 	DEV_ST_TRANSITION_MAX,
 };
 
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index d9964d4..345f197 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -657,6 +657,10 @@ void mhi_pm_st_worker(struct work_struct *work)
 			mhi_pm_disable_transition
 				(mhi_cntrl, MHI_PM_SYS_ERR_PROCESS);
 			break;
+		case DEV_ST_TRANSITION_DISABLE:
+			mhi_pm_disable_transition
+				(mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS);
+			break;
 		default:
 			break;
 		}
@@ -1011,7 +1015,12 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful)
 				to_mhi_pm_state_str(MHI_PM_LD_ERR_FATAL_DETECT),
 				to_mhi_pm_state_str(mhi_cntrl->pm_state));
 	}
-	mhi_pm_disable_transition(mhi_cntrl, MHI_PM_SHUTDOWN_PROCESS);
+
+	mhi_queue_state_transition(mhi_cntrl, DEV_ST_TRANSITION_DISABLE);
+
+	/* Wait for shutdown to complete */
+	flush_work(&mhi_cntrl->st_worker);
+
 	mhi_deinit_free_irq(mhi_cntrl);
 
 	if (!mhi_cntrl->pre_init) {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project