[PATCH V3 06/14] i3c: master: Fix potential UAF in i3c_device_uevent()
Mukesh Savaliya
mukesh.savaliya at oss.qualcomm.com
Tue Aug 4 11:12:01 PDT 2026
On 8/4/2026 7:08 PM, Adrian Hunter wrote:
> 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 at vger.kernel.org # requires "i3c: master: Fix recursive locking during device registration"
> Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
> ---
>
>
> Changes in V3:
>
> New patch
>
>
> drivers/i3c/master.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
Acked-by: Mukesh Savaliya <mukesh.savaliya at oss.qualcomm.com>
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