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| author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2019-06-21 20:52:05 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-03 22:16:37 +0300 |
| commit | 17c20f329a139e90e4b049b811ca6d1a2ae967e0 (patch) | |
| tree | 083d3d84e0b65074d95ec5dda2bc861694ba62b7 | |
| parent | 020601622323d02e09cebe05e7976b3d4b44e05d (diff) | |
| download | linux-17c20f329a139e90e4b049b811ca6d1a2ae967e0.tar.xz | |
coresight: tmc: Smatch: Fix potential NULL pointer dereference
Based on the following report from Smatch, fix the potential
NULL pointer dereference check.
The patch 743256e214e8: "coresight: tmc: Clean up device specific
data" from May 22, 2019, leads to the following Smatch complaint:
drivers/hwtracing/coresight/coresight-tmc-etr.c:625 tmc_etr_free_flat_buf()
warn: variable dereferenced before check 'flat_buf' (see line 623)
drivers/hwtracing/coresight/coresight-tmc-etr.c
622 struct etr_flat_buf *flat_buf = etr_buf->private;
623 struct device *real_dev = flat_buf->dev->parent;
^^^^^^^^^^
The patch introduces a new NULL check
624
625 if (flat_buf && flat_buf->daddr)
^^^^^^^^
but the existing code assumed it can be NULL.
626 dma_free_coherent(real_dev, flat_buf->size,
627 flat_buf->vaddr, flat_buf->daddr);
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20190621175205.24551-3-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc-etr.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 5d2bf6d18961..17006705287a 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -620,11 +620,13 @@ static int tmc_etr_alloc_flat_buf(struct tmc_drvdata *drvdata, static void tmc_etr_free_flat_buf(struct etr_buf *etr_buf) { struct etr_flat_buf *flat_buf = etr_buf->private; - struct device *real_dev = flat_buf->dev->parent; - if (flat_buf && flat_buf->daddr) + if (flat_buf && flat_buf->daddr) { + struct device *real_dev = flat_buf->dev->parent; + dma_free_coherent(real_dev, flat_buf->size, flat_buf->vaddr, flat_buf->daddr); + } kfree(flat_buf); } |