4.19-stable review patch. If anyone has any objections, please let me know.
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From: Johan Hovold johan@kernel.org
commit 5d1e9c2212ea6b4dd735e4fc3dd6279a365d5d10 upstream.
Use the new of_get_compatible_child() helper to lookup the nfc child node instead of using of_find_compatible_node(), which searches the entire tree from a given start node and thus can return an unrelated (i.e. non-child) node.
This also addresses a potential use-after-free (e.g. after probe deferral) as the tree-wide helper drops a reference to its first argument (i.e. the node of the device being probed).
While at it, also fix a related nfc-node reference leak.
Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver") Cc: stable stable@vger.kernel.org # 4.11 Cc: Nicolas Ferre nicolas.ferre@microchip.com Cc: Josh Wu rainyfeeling@outlook.com Cc: Boris Brezillon boris.brezillon@bootlin.com Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mtd/nand/raw/atmel/nand-controller.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/drivers/mtd/nand/raw/atmel/nand-controller.c +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c @@ -2061,8 +2061,7 @@ atmel_hsmc_nand_controller_legacy_init(s int ret;
nand_np = dev->of_node; - nfc_np = of_find_compatible_node(dev->of_node, NULL, - "atmel,sama5d3-nfc"); + nfc_np = of_get_compatible_child(dev->of_node, "atmel,sama5d3-nfc"); if (!nfc_np) { dev_err(dev, "Could not find device node for sama5d3-nfc\n"); return -ENODEV; @@ -2476,15 +2475,19 @@ static int atmel_nand_controller_probe(s }
if (caps->legacy_of_bindings) { + struct device_node *nfc_node; u32 ale_offs = 21;
/* * If we are parsing legacy DT props and the DT contains a * valid NFC node, forward the request to the sama5 logic. */ - if (of_find_compatible_node(pdev->dev.of_node, NULL, - "atmel,sama5d3-nfc")) + nfc_node = of_get_compatible_child(pdev->dev.of_node, + "atmel,sama5d3-nfc"); + if (nfc_node) { caps = &atmel_sama5_nand_caps; + of_node_put(nfc_node); + }
/* * Even if the compatible says we are dealing with an