[PATCH 4/9] mmc: meson-mx-sdio: fix OF child-node lookup
From: Johan Hovold <johan@kernel.org>
Date: 2018-08-22 10:57:39
Also in:
lkml, stable
Subsystem:
arm/amlogic meson soc support, multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Neil Armstrong, Kevin Hilman, Ulf Hansson, Linus Torvalds
Use the new of_get_compatible_child() helper to lookup the slot child
node instead of using of_find_compatible_node(), which searches the
entire tree 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 up the related slot-node reference leak.
Fixes: ed80a13bb4c4 ("mmc: meson-mx-sdio: Add a driver for the Amlogic Meson8 and Meson8b SoCs")
Cc: stable <redacted> # 4.15
Cc: Carlo Caione <redacted>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Ulf Hansson <redacted>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/mmc/host/meson-mx-sdio.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/meson-mx-sdio.c b/drivers/mmc/host/meson-mx-sdio.c
index 09cb89645d06..2cfec33178c1 100644
--- a/drivers/mmc/host/meson-mx-sdio.c
+++ b/drivers/mmc/host/meson-mx-sdio.c@@ -517,19 +517,23 @@ static struct mmc_host_ops meson_mx_mmc_ops = { static struct platform_device *meson_mx_mmc_slot_pdev(struct device *parent) { struct device_node *slot_node; + struct platform_device *pdev; /* * TODO: the MMC core framework currently does not support * controllers with multiple slots properly. So we only register * the first slot for now */ - slot_node = of_find_compatible_node(parent->of_node, NULL, "mmc-slot"); + slot_node = of_get_compatible_child(parent->of_node, "mmc-slot"); if (!slot_node) { dev_warn(parent, "no 'mmc-slot' sub-node found\n"); return ERR_PTR(-ENOENT); } - return of_platform_device_create(slot_node, NULL, parent); + pdev = of_platform_device_create(slot_node, NULL, parent); + of_node_put(slot_node); + + return pdev; } static int meson_mx_mmc_add_host(struct meson_mx_mmc_host *host)
--
2.18.0