CVE-2026-72454 i3c: mipi-i3c-hci: Fix race in i3c_hci_addr_to_dev()
A race condition in the Linux kernel I3C HCI driver allows concurrent list modification, potentially causing use-after-free crashes or code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72454?
CVE-2026-72454 is a high-severity vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
i3c: mipi-i3c-hci: Fix race in i3c_hci_addr_to_dev()
i3c_hci_addr_to_dev() walks bus->devs.i3c, which is protected by bus.lock (rwsem). However, it is invoked from the MIPI I3C HCI IRQ handler, which cannot take bus.lock. This allows concurrent device addition/removal in the I3C core to modify the list while it is being traversed, potentially leading to use-after-free or crashes.
Remove the dependency on the bus device list and introduce a dedicated lookup table. Add an ibi_devs[] array indexed by DAT entry, maintained under hci->lock. Update the array when IBIs are enabled or disabled, so that it always reflects the set of devices allowed to generate IBIs. Also update when IBIs are freed, to cover the corner case when an IBI is freed without first being disabled (e.g. oldedev in i3c_master_add_i3c_dev_locked()).
Move i3c_hci_addr_to_dev() into core.c, reimplement it using the new array, and add a lockdep assertion to enforce that hci->lock is held by callers.
Demote a message in PIO and DMA IBI handling, from an error to a debug message, because there is a race window when the condition can arise normally.
Which versions are affected by CVE-2026-72454?
How do I fix CVE-2026-72454?
Apply the vendor's patch.
Is CVE-2026-72454 being exploited?
There is no known exploitation of CVE-2026-72454 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-72454, DEBIAN-CVE-2026-72454, GHSA-48cg-fm56-jr4v, UBUNTU-CVE-2026-72454.