From e5e8dd2e959f470524c16ca444d001c90d6bb3ad Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 7 Aug 2026 17:56:30 +0300 Subject: [PATCH] i3c: master: Fix potential UAF in i3c_device_uevent() i3c_device_uevent() dereferences i3cdev->desc without holding the bus normal-use lock. Since the descriptor pointer can be replaced concurrently, including when a uevent is generated from sysfs, this can result in dereferencing a stale descriptor and lead to a use-after-free. Use i3c_device_get_info() instead, which protects access to the descriptor with the normal-use lock. Commit 6cf7b65f7029 ("i3c: Use i3cdev->desc->info instead of calling i3c_device_get_info() to avoid deadlock") replaced the accessor with a direct descriptor dereference because i3c_device_get_info() would recursively acquire bus->lock during device registration. This change depends on "i3c: master: Fix recursive locking during device registration", which moves device registration out from under bus->lock and removes the possibility of that deadlock. Without that change, restoring the i3c_device_get_info() call would reintroduce the deadlock. Fixes: 6cf7b65f7029 ("i3c: Use i3cdev->desc->info instead of calling i3c_device_get_info() to avoid deadlock") Cc: stable@vger.kernel.org # requires "i3c: master: Fix recursive locking during device registration" Signed-off-by: Adrian Hunter Acked-by: Mukesh Savaliya Reviewed-by: Frank Li Link: https://patch.msgid.link/20260807145638.168865-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni --- drivers/i3c/master.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 2357874bb9d6..ee771ac0b203 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -316,8 +316,7 @@ static int i3c_device_uevent(const struct device *dev, struct kobj_uevent_env *e struct i3c_device_info devinfo; u16 manuf, part, ext; - if (i3cdev->desc) - devinfo = i3cdev->desc->info; + i3c_device_get_info(i3cdev, &devinfo); manuf = I3C_PID_MANUF_ID(devinfo.pid); part = I3C_PID_PART_ID(devinfo.pid); ext = I3C_PID_EXTRA_INFO(devinfo.pid);