CVE-2026-80764 Bluetooth: hci_event: fix LE list UAF on reset
A race condition in the Linux kernel Bluetooth subsystem allows a local attacker to trigger a use-after-free, potentially causing a system crash or arbitrary 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-2026-80764?
CVE-2026-80764 is an use after free vulnerability in Linux, published on 4 Sep 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:
Bluetooth: hci_event: fix LE list UAF on reset
hci_cc_reset() clears the LE accept and resolving lists without taking hdev->lock. Other command-complete handlers serialize updates to these lists with that lock, and the debugfs readers hold it while walking them.
This permits the reset completion and a debugfs read to interleave as follows:
hci_rx_work debugfs reader ----------- -------------- lock hdev->lock fetch current entry list_del(entry) kfree(entry) read entry fields
The reader then dereferences a freed list entry and may follow its stale next pointer.
KASAN reported:
BUG: KASAN: slab-use-after-free in white_list_show+0x15f/0x180 Read of size 1 at addr ffff8881015dab16 by task poc/95
Call Trace: white_list_show+0x15f/0x180 seq_read_iter+0x3ff/0x1190 seq_read+0x267/0x3d0 vfs_read+0x177/0xa20 ksys_read+0xf7/0x1c0
Allocated by task 91: hci_bdaddr_list_add+0x1a6/0x3a0 hci_cc_le_add_to_accept_list+0xab/0x140 hci_cmd_complete_evt+0x26c/0x9a0 hci_event_packet+0x454/0xb20 hci_rx_work+0x293/0x730
Freed by task 90: kfree+0x131/0x3c0 hci_bdaddr_list_clear+0xd8/0x160 hci_cc_reset+0x28a/0x370 hci_cmd_complete_evt+0x26c/0x9a0 hci_event_packet+0x454/0xb20 hci_rx_work+0x293/0x730
Take hdev->lock around both list clears. This matches the existing mutation and traversal locking convention.
Which versions are affected by CVE-2026-80764?
How do I fix CVE-2026-80764?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-80764 being exploited?
There is no known exploitation of CVE-2026-80764 in the wild and no public exploit code.
Sources
Also known as AZL-99575, BELL-CVE-2026-80764, DEBIAN-CVE-2026-80764, GHSA-8pvh-g785-qf97, UBUNTU-CVE-2026-80764.