[PATCH v5 11/11] rpmsg: Fix kfree() of static memory on setting driver_override
From: Krzysztof Kozlowski <hidden>
Date: 2022-03-16 15:10:39
Also in:
alsa-devel, linux-arm-kernel, linux-arm-msm, linux-clk, linux-pci, linux-remoteproc, linux-s390, linux-spi, lkml, stable
Subsystem:
remote processor messaging (rpmsg) subsystem, the rest · Maintainers:
Bjorn Andersson, Mathieu Poirier, Linus Torvalds
The driver_override field from platform driver should not be initialized
from static memory (string literal) because the core later kfree() it,
for example when driver_override is set via sysfs.
Use dedicated helper to set driver_override properly.
Fixes: 950a7388f02b ("rpmsg: Turn name service into a stand alone driver")
Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface")
Cc: <redacted>
Signed-off-by: Krzysztof Kozlowski <redacted>
Reviewed-by: Bjorn Andersson <redacted>
---
drivers/rpmsg/rpmsg_core.c | 3 ++-
drivers/rpmsg/rpmsg_internal.h | 11 +++++++++--
drivers/rpmsg/rpmsg_ns.c | 14 ++++++++++++--
include/linux/rpmsg.h | 6 ++++--
4 files changed, 27 insertions(+), 7 deletions(-)
diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 79368a957d89..95fc283f6af7 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c@@ -400,7 +400,8 @@ field##_store(struct device *dev, struct device_attribute *attr, \ const char *buf, size_t sz) \ { \ struct rpmsg_device *rpdev = to_rpmsg_device(dev); \ - char *new, *old; \ + const char *old; \ + char *new; \ \ new = kstrndup(buf, sz, GFP_KERNEL); \ if (!new) \
diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index d4b23fd019a8..dd1f4ed616b6 100644
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h@@ -95,9 +95,16 @@ int rpmsg_release_channel(struct rpmsg_device *rpdev, static inline int rpmsg_ctrldev_register_device(struct rpmsg_device *rpdev) { strcpy(rpdev->id.name, "rpmsg_ctrl"); - rpdev->driver_override = "rpmsg_ctrl"; + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, + "rpmsg_ctrl", strlen("rpmsg_ctrl")); + if (ret) + return ret; - return rpmsg_register_device(rpdev); + ret = rpmsg_register_device(rpdev); + if (ret) + kfree(rpdev->driver_override); + + return ret; } #endif
diff --git a/drivers/rpmsg/rpmsg_ns.c b/drivers/rpmsg/rpmsg_ns.c
index 762ff1ae279f..95a51543f5ad 100644
--- a/drivers/rpmsg/rpmsg_ns.c
+++ b/drivers/rpmsg/rpmsg_ns.c@@ -20,12 +20,22 @@ */ int rpmsg_ns_register_device(struct rpmsg_device *rpdev) { + int ret; + strcpy(rpdev->id.name, "rpmsg_ns"); - rpdev->driver_override = "rpmsg_ns"; + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, + "rpmsg_ns", strlen("rpmsg_ns")); + if (ret) + return ret; + rpdev->src = RPMSG_NS_ADDR; rpdev->dst = RPMSG_NS_ADDR; - return rpmsg_register_device(rpdev); + ret = rpmsg_register_device(rpdev); + if (ret) + kfree(rpdev->driver_override); + + return ret; } EXPORT_SYMBOL(rpmsg_ns_register_device);
diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h
index 02fa9116cd60..20c8cd1cde21 100644
--- a/include/linux/rpmsg.h
+++ b/include/linux/rpmsg.h@@ -41,7 +41,9 @@ struct rpmsg_channel_info { * rpmsg_device - device that belong to the rpmsg bus * @dev: the device struct * @id: device id (used to match between rpmsg drivers and devices) - * @driver_override: driver name to force a match + * @driver_override: driver name to force a match; do not set directly, + * because core frees it; use driver_set_override() to + * set or clear it. * @src: local address * @dst: destination address * @ept: the rpmsg endpoint of this channel
@@ -51,7 +53,7 @@ struct rpmsg_channel_info { struct rpmsg_device { struct device dev; struct rpmsg_device_id id; - char *driver_override; + const char *driver_override; u32 src; u32 dst; struct rpmsg_endpoint *ept;
--
2.32.0