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Likewise, if name is > NULL and the OF/ACPI lookup does not succeed, the legacy filter-map path > eventually passes it to strcmp(), resulting in a NULL pointer dereference. > > These are caller bugs rather than normal lookup failures, so add a > WARN_ON() at function entry to catch invalid arguments early during > development instead of crashing later. > > No functional change for valid callers. > > Signed-off-by: bui duc phuc > --- Reviewed-by: Frank Li > drivers/dma/dmaengine.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c > index 9049171df857..7b479cd93b9b 100644 > --- a/drivers/dma/dmaengine.c > +++ b/drivers/dma/dmaengine.c > @@ -814,10 +814,15 @@ static const struct dma_slave_map *dma_filter_match(struct dma_device *device, > */ > struct dma_chan *dma_request_chan(struct device *dev, const char *name) > { > - struct fwnode_handle *fwnode = dev_fwnode(dev); > + struct fwnode_handle *fwnode; > struct dma_device *d, *_d; > struct dma_chan *chan = NULL; > > + if (WARN_ON(!dev || !name)) > + return ERR_PTR(-EINVAL); > + > + fwnode = dev_fwnode(dev); > + > if (is_of_node(fwnode)) > chan = of_dma_request_slave_channel(to_of_node(fwnode), name); > else if (is_acpi_device_node(fwnode)) > -- > 2.43.0 >