Live › vulnerability › CVE-2026-98737
Go to dashboardA race in the Linux kernel Bluetooth HCI code lets the inquiry cache be flushed while a sync worker still reads a freed entry. The sources describe a use-after-free that KASAN caught, and do not state what an attacker can achieve beyond that.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems running a Linux kernel with the Bluetooth HCI stack enabled and in use, such as laptops, desktops and devices with Bluetooth adapters. Servers and containers without Bluetooth hardware or with the module not loaded are unlikely to be exposed. The sources do not say which kernel versions are affected.
No product ranges from the sources yet.
uname -r and compare against the fixed kernel builds listed in the NVD entrylsmod | grep -i bluetooth to see whether the Bluetooth stack is loaded at allmodprobe -r bluetooth) on hosts that do not need Bluetooth removes the exposed code pathEach row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: Fix inquiry cache use-after-free
The sync command worker holds hdev->req_lock, but inquiry-cache updates and flushes use hdev->lock. Both hci_acl_create_conn_sync() and hci_stop_discovery_sync() look up entries and read their fields without taking hdev->lock.
After either lookup returns, a concurrent HCIINQUIRY ioctl can acquire hdev->lock and flush the cache, freeing the entry. The worker then reads the freed entry while preparing a create-connection or remote-name-cancel command. The list traversal also races with cache updates and removal.
KASAN reported these accesses:
BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0x5f1/0x650 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_acl_create_conn_sync+0x5f1/0x650 hci_cmd_sync_work+0x13c/0x290
Allocated by task 90: hci_inquiry_cache_update+0x3e6/0x7d0 hci_inquiry_result_evt+0x3cb/0x560
Freed by task 93: hci_inquiry_cache_flush+0x111/0x2b0 hci_inquiry+0x2f2/0x780 hci_sock_ioctl+0x269/0x5f0
BUG: KASAN: slab-use-after-free in hci_stop_discovery_sync+0x3b1/0x3c0 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_stop_discovery_sync+0x3b1/0x3c0 hci_cmd_sync_work+0x173/0x300
Allocated by task 86: hci_inquiry_cache_update+0x483/0x940 hci_inquiry_result_evt+0x3cb/0x560
Freed by task 91: hci_inquiry_cache_flush+0x13e/0x2f0 hci_inquiry+0x2f2/0x780 hci_sock_ioctl+0x269/0x5f0
Hold hdev->lock across each lookup and all reads from its result. Copy the remote address before unlocking so discovery cancellation does not retain a cache entry pointer. Release the lock before sending synchronous HCI commands, since their completion handlers may need the same lock.
This page as .md · .json · in your agent: get_signal("CVE-2026-98737")
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.