| Message ID | 1560420386-4239-2-git-send-email-suzuki.poulose@arm.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 17c20f329a139e90e4b049b811ca6d1a2ae967e0 |
| Headers | show |
| Series | [1/2] coresight: etm3x: Smatch: Fix potential NULL pointer dereference | expand |
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 5d2bf6d..1700670 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); }
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> --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)