The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 148891e95014b5dc5878acefa57f1940c281c431 Mon Sep 17 00:00:00 2001 From: Gui-Dong Han <[email protected]> Date: Wed, 3 Dec 2025 01:44:38 +0800 Subject: [PATCH] bus: fsl-mc: fix use-after-free in driver_override_show() The driver_override_show() function reads the driver_override string without holding the device_lock. However, driver_override_store() uses driver_set_override(), which modifies and frees the string while holding the device_lock. This can result in a concurrent use-after-free if the string is freed by the store function while being read by the show function. Fix this by holding the device_lock around the read operation. Fixes: 1f86a00c1159 ("bus/fsl-mc: add support for 'driver_override' in the mc-bus") Cc: [email protected] Signed-off-by: Gui-Dong Han <[email protected]> Reviewed-by: Ioana Ciornei <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Christophe Leroy (CS GROUP) <[email protected]> --- drivers/bus/fsl-mc/fsl-mc-bus.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index c08c04047ae2c..08b99b0b342f3 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -231,8 +231,12 @@ static ssize_t driver_override_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev); + ssize_t len; - return sysfs_emit(buf, "%s\n", mc_dev->driver_override); + device_lock(dev); + len = sysfs_emit(buf, "%s\n", mc_dev->driver_override); + device_unlock(dev); + return len; } static DEVICE_ATTR_RW(driver_override); -- 2.51.0
