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From: Dan Carpenter <dan.carpenter@linaro.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>, Leo Yan <leo.yan@linaro.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH] coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet()
Date: Fri, 21 Apr 2023 13:42:41 +0300	[thread overview]
Message-ID: <7d33e244-d8b9-4c27-9653-883a13534b01@kili.mountain> (raw)

This code generates a Smatch warning:

    drivers/hwtracing/coresight/coresight-tmc-etr.c:947 tmc_etr_buf_insert_barrier_packet()
    error: uninitialized symbol 'bufp'.

The problem is that if tmc_sg_table_get_data() returns -EINVAL, then
when we test if "len < CORESIGHT_BARRIER_PKT_SIZE", the negative "len"
value is type promoted to a high unsigned long value which is greater
than CORESIGHT_BARRIER_PKT_SIZE.  Fix this bug by adding an explicit
check for error codes.

Fixes: 75f4e3619fe2 ("coresight: tmc-etr: Add transparent buffer management")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 918d461fcf4a..eaa296ced167 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -942,7 +942,7 @@ tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
 
 	len = tmc_etr_buf_get_data(etr_buf, offset,
 				   CORESIGHT_BARRIER_PKT_SIZE, &bufp);
-	if (WARN_ON(len < CORESIGHT_BARRIER_PKT_SIZE))
+	if (WARN_ON(len < 0 || len < CORESIGHT_BARRIER_PKT_SIZE))
 		return -EINVAL;
 	coresight_insert_barrier_packet(bufp);
 	return offset + CORESIGHT_BARRIER_PKT_SIZE;
-- 
2.39.2


WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>, Leo Yan <leo.yan@linaro.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH] coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet()
Date: Fri, 21 Apr 2023 13:42:41 +0300	[thread overview]
Message-ID: <7d33e244-d8b9-4c27-9653-883a13534b01@kili.mountain> (raw)

This code generates a Smatch warning:

    drivers/hwtracing/coresight/coresight-tmc-etr.c:947 tmc_etr_buf_insert_barrier_packet()
    error: uninitialized symbol 'bufp'.

The problem is that if tmc_sg_table_get_data() returns -EINVAL, then
when we test if "len < CORESIGHT_BARRIER_PKT_SIZE", the negative "len"
value is type promoted to a high unsigned long value which is greater
than CORESIGHT_BARRIER_PKT_SIZE.  Fix this bug by adding an explicit
check for error codes.

Fixes: 75f4e3619fe2 ("coresight: tmc-etr: Add transparent buffer management")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 918d461fcf4a..eaa296ced167 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -942,7 +942,7 @@ tmc_etr_buf_insert_barrier_packet(struct etr_buf *etr_buf, u64 offset)
 
 	len = tmc_etr_buf_get_data(etr_buf, offset,
 				   CORESIGHT_BARRIER_PKT_SIZE, &bufp);
-	if (WARN_ON(len < CORESIGHT_BARRIER_PKT_SIZE))
+	if (WARN_ON(len < 0 || len < CORESIGHT_BARRIER_PKT_SIZE))
 		return -EINVAL;
 	coresight_insert_barrier_packet(bufp);
 	return offset + CORESIGHT_BARRIER_PKT_SIZE;
-- 
2.39.2


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             reply	other threads:[~2023-04-21 10:42 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-21 10:42 Dan Carpenter [this message]
2023-04-21 10:42 ` [PATCH] coresight: Fix signedness bug in tmc_etr_buf_insert_barrier_packet() Dan Carpenter
2023-04-21 12:12 ` Suzuki K Poulose
2023-04-21 12:12   ` Suzuki K Poulose

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