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| author | Gui-Dong Han <hanguidong02@gmail.com> | 2025-12-03 01:44:38 +0800 |
|---|---|---|
| committer | Christophe Leroy (CS GROUP) <chleroy@kernel.org> | 2026-01-06 18:56:32 +0100 |
| commit | 148891e95014b5dc5878acefa57f1940c281c431 (patch) | |
| tree | 569b7fb51c68223bceb329f8133cc3a6591d9c34 | |
| parent | c8dff80a3108a2cb85ac7ac5b1a75c247ac55fd2 (diff) | |
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: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20251202174438.12658-1-hanguidong02@gmail.com
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
| -rw-r--r-- | drivers/bus/fsl-mc/fsl-mc-bus.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index c08c04047ae2..08b99b0b342f 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); |