From f497d3c5e86d4865dd637ebca048dc915a8224d2 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Tue, 31 Oct 2023 11:25:37 +0000 Subject: [PATCH] BACKPORT: rpmsg: Fix kfree() of static memory on setting driver_override commit 42cd402b8fd4672b692400fe5f9eecd55d2794ac upstream. 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. Bug: 295334746 Fixes: 950a7388f02b ("rpmsg: Turn name service into a stand alone driver") Fixes: c0cdc19f84a4 ("rpmsg: Driver for user space endpoint interface") Reviewed-by: Bjorn Andersson Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20220419113435.246203-13-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 2e76b4f6218c4db3ff00eb15d94d72f371736de4) [Lee: Cater for name change s/rpmsg_chrdev/rpmsg_ctrl/ due to previous backport] Signed-off-by: Lee Jones Change-Id: Ib900ad13efcfdf7e50fb92bb45dff2b8aa8ff443 --- drivers/rpmsg/rpmsg_internal.h | 15 ++++++++++++--- include/linux/rpmsg.h | 6 ++++-- 2 files changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h index 8958d6c94e9a..0529196c501a 100644 --- a/drivers/rpmsg/rpmsg_internal.h +++ b/drivers/rpmsg/rpmsg_internal.h @@ -89,10 +89,19 @@ struct device *rpmsg_find_device(struct device *parent, */ static inline int rpmsg_chrdev_register_device(struct rpmsg_device *rpdev) { - strcpy(rpdev->id.name, "rpmsg_chrdev"); - rpdev->driver_override = "rpmsg_chrdev"; + int ret; - return rpmsg_register_device(rpdev); + strcpy(rpdev->id.name, "rpmsg_chrdev"); + ret = driver_set_override(&rpdev->dev, &rpdev->driver_override, + rpdev->id.name, strlen(rpdev->id.name)); + if (ret) + return ret; + + ret = rpmsg_register_device(rpdev); + if (ret) + kfree(rpdev->driver_override); + + return ret; } #endif diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h index a349f21ddabb..68b5d0192550 100644 --- a/include/linux/rpmsg.h +++ b/include/linux/rpmsg.h @@ -42,7 +42,9 @@ 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;