linux-kernel - [PATCH 4.4 20/69] mei: txe: dont clean an unprocessed interrupt cause.

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: <20161109102901.995930598@linuxfoundation.org>
Date:   Wed,  9 Nov 2016 11:43:58 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Alexander Usyskin <alexander.usyskin@...el.com>,
        Tomas Winkler <tomas.winkler@...el.com>
Subject: [PATCH 4.4 20/69] mei: txe: dont clean an unprocessed interrupt cause.

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alexander Usyskin <alexander.usyskin@...el.com>

commit 43605e293eb13c07acb546c14f407a271837af17 upstream.

SEC registers are not accessible when the TXE device is in low power
state, hence the SEC interrupt cannot be processed if device is not
awake.

In some rare cases entrance to low power state (aliveness off) and input
ready bits can be signaled at the same time, resulting in communication
stall as input ready won't be signaled again after waking up. To resolve
this IPC_HHIER_SEC bit in HHISR_REG should not be cleaned if the
interrupt is not processed.

Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/misc/mei/hw-txe.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/misc/mei/hw-txe.c
+++ b/drivers/misc/mei/hw-txe.c
@@ -972,11 +972,13 @@ static bool mei_txe_check_and_ack_intrs(
 	hisr = mei_txe_br_reg_read(hw, HISR_REG);
 
 	aliveness = mei_txe_aliveness_get(dev);
-	if (hhisr & IPC_HHIER_SEC && aliveness)
+	if (hhisr & IPC_HHIER_SEC && aliveness) {
 		ipc_isr = mei_txe_sec_reg_read_silent(hw,
 				SEC_IPC_HOST_INT_STATUS_REG);
-	else
+	} else {
 		ipc_isr = 0;
+		hhisr &= ~IPC_HHIER_SEC;
+	}
 
 	generated = generated ||
 		(hisr & HISR_INT_STS_MSK) ||