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Message-Id: <20240827143237.10208-1-wen.yang@linux.dev>
Date: Tue, 27 Aug 2024 22:32:37 +0800
From: Wen Yang <wen.yang@...ux.dev>
To: Sudeep Holla <sudeep.holla@....com>,
Cristian Marussi <cristian.marussi@....com>
Cc: Wen Yang <wen.yang@...ux.dev>,
arm-scmi@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org
Subject: [PATCH] firmware: arm_scmi: protect xfer->async_done with xfer->lock when changing and using it
do_xfer_with_response() first assigns xfer->async_done to &async_response,
then calls wait_for_completion_timeout(), and finally sets xfer->async_done
to null.
However, scmi_handle_response() may calls complete(xfer->async_done) while
xfer->async_done is null, may causing a crash.
Protect xfer->async_done with xfer->lock when changing and using it,
just like scmi_msg_response_validate().
Signed-off-by: Wen Yang <wen.yang@...ux.dev>
Cc: Sudeep Holla <sudeep.holla@....com>
Cc: Cristian Marussi <cristian.marussi@....com>
Cc: arm-scmi@...r.kernel.org
Cc: linux-arm-kernel@...ts.infradead.org
Cc: linux-kernel@...r.kernel.org
---
drivers/firmware/arm_scmi/driver.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 66806578df5a..24ed94e3cbd4 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -1110,6 +1110,7 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
{
struct scmi_xfer *xfer;
struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
+ unsigned long flags;
xfer = scmi_xfer_command_acquire(cinfo, msg_hdr);
if (IS_ERR(xfer)) {
@@ -1144,7 +1145,10 @@ static void scmi_handle_response(struct scmi_chan_info *cinfo,
if (xfer->hdr.type == MSG_TYPE_DELAYED_RESP) {
scmi_clear_channel(info, cinfo);
- complete(xfer->async_done);
+ spin_lock_irqsave(&xfer->lock, flags);
+ if (xfer->async_done)
+ complete(xfer->async_done);
+ spin_unlock_irqrestore(&xfer->lock, flags);
scmi_inc_count(info->dbg->counters, DELAYED_RESPONSE_OK);
} else {
complete(&xfer->done);
@@ -1479,9 +1483,13 @@ static int do_xfer_with_response(const struct scmi_protocol_handle *ph,
struct scmi_xfer *xfer)
{
int ret, timeout = msecs_to_jiffies(SCMI_MAX_RESPONSE_TIMEOUT);
+ unsigned long flags;
+
DECLARE_COMPLETION_ONSTACK(async_response);
+ spin_lock_irqsave(&xfer->lock, flags);
xfer->async_done = &async_response;
+ spin_unlock_irqrestore(&xfer->lock, flags);
/*
* Delayed responses should not be polled, so an async command should
@@ -1503,7 +1511,10 @@ static int do_xfer_with_response(const struct scmi_protocol_handle *ph,
}
}
+ spin_lock_irqsave(&xfer->lock, flags);
xfer->async_done = NULL;
+ spin_unlock_irqrestore(&xfer->lock, flags);
+
return ret;
}
--
2.25.1
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