In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: Fix UAF in hci_disconnect_all_sync
Use-after-free can occur in hci_disconnect_all_sync if a connection is deleted by concurrent processing of a controller event.
To prevent this the code now tries to iterate over the list backwards to ensure the links are cleanup before its parents, also it no longer relies on a cursor, instead it always uses the last element since hci_abort_conn_sync is guaranteed to call hci_conn_del.
UAF crash log: ================================================================== BUG: KASAN: slab-use-after-free in hci_set_powered_sync (net/bluetooth/hci_sync.c:5424) [bluetooth] Read of size 8 at addr ffff888009d9c000 by task kworker/u9:0/124
CPU: 0 PID: 124 Comm: kworker/u9:0 Tainted: G W 6.5.0-rc1+ #10 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014 Workqueue: hci0 hci_cmd_sync_work [bluetooth] Call Trace: <TASK> dump_stack_lvl+0x5b/0x90 print_report+0xcf/0x670 ? __virt_addr_valid+0xdd/0x160 ? hci_set_powered_sync+0x2c9/0x4a0 [bluetooth] kasan_report+0xa6/0xe0 ? hci_set_powered_sync+0x2c9/0x4a0 [bluetooth] ? __pfx_set_powered_sync+0x10/0x10 [bluetooth] hci_set_powered_sync+0x2c9/0x4a0 [bluetooth] ? __pfx_hci_set_powered_sync+0x10/0x10 [bluetooth] ? __pfx_lock_release+0x10/0x10 ? __pfx_set_powered_sync+0x10/0x10 [bluetooth] hci_cmd_sync_work+0x137/0x220 [bluetooth] process_one_work+0x526/0x9d0 ? __pfx_process_one_work+0x10/0x10 ? __pfx_do_raw_spin_lock+0x10/0x10 ? mark_held_locks+0x1a/0x90 worker_thread+0x92/0x630 ? __pfx_worker_thread+0x10/0x10 kthread+0x196/0x1e0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 </TASK>
Allocated by task 1782: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 __kasan_kmalloc+0x8f/0xa0 hci_conn_add+0xa5/0xa80 [bluetooth] hci_bind_cis+0x881/0x9b0 [bluetooth] iso_connect_cis+0x121/0x520 [bluetooth] iso_sock_connect+0x3f6/0x790 [bluetooth] __sys_connect+0x109/0x130 __x64_sys_connect+0x40/0x50 do_syscall_64+0x60/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Freed by task 695: kasan_save_stack+0x33/0x60 kasan_set_track+0x25/0x30 kasan_save_free_info+0x2b/0x50 __kasan_slab_free+0x10a/0x180 __kmem_cache_free+0x14d/0x2e0 device_release+0x5d/0xf0 kobject_put+0xdf/0x270 hci_disconn_complete_evt+0x274/0x3a0 [bluetooth] hci_event_packet+0x579/0x7e0 [bluetooth] hci_rx_work+0x287/0xaa0 [bluetooth] process_one_work+0x526/0x9d0 worker_thread+0x92/0x630 kthread+0x196/0x1e0 ret_from_fork+0x2c/0x50 ==================================================================
CVSS Details
- CVSS 3.1 Base Score: 8.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade kernel-debug-coreUpgrade kernel-rt-debug-modules-extraUpgrade kernel-coreUpgrade kernel-zfcpdumpUpgrade kernel-modules-extraUpgrade perfUpgrade kernel-docUpgrade kernel-modulesUpgrade kernel-debug-modules-extraUpgrade kernel-zfcpdump-modules-extraUpgrade kernel-rt-debug-develUpgrade kernel-rt-coreUpgrade kernel-rt-debug-modulesUpgrade kernel-debugUpgrade kernel-headersUpgrade kernel-zfcpdump-develUpgrade kernel-rt-modulesUpgrade kernel-debug-develUpgrade kernel-abi-stablelistsUpgrade kernel-rt-debug-coreUpgrade kernel-zfcpdump-modulesUpgrade python3-perfUpgrade kernel-cross-headersUpgrade kernel-tools-libsUpgrade bpftoolUpgrade kernel-rt-modules-extraUpgrade kernelUpgrade kernel-develUpgrade kernel-rt-develUpgrade kernel-rt-debugUpgrade kernel-zfcpdump-coreUpgrade kernel-tools-libs-develUpgrade kernel-rtUpgrade kernel-debug-modulesUpgrade kernel-tools | Feb 24, 2026 | Feb 17, 2026 |
| Debian | — | Upgrade linux | Jul 27, 2026 | Jul 27, 2026 |
| Oracle_linux | — | Upgrade kernel | Feb 24, 2026 | Dec 8, 2025 |
| Redhat_linux | — | Upgrade kernel-rtUpgrade kernelNo solution exists | Mar 13, 2026 | Dec 8, 2025 |
| Rocky_linux | — | Upgrade kernel-rt-debuginfoUpgrade kernel-rt-kvmUpgrade kernel-debug-modules-extraUpgrade kernel-rt-debug-debuginfoUpgrade kernel-toolsUpgrade kernel-rt-modules-extraUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-rt-debug-coreUpgrade bpftoolUpgrade kernel-rtUpgrade kernel-rt-modulesUpgrade kernel-tools-libs-develUpgrade perfUpgrade kernel-rt-debug-modulesUpgrade kernel-debuginfoUpgrade kernel-debug-develUpgrade kernel-debugUpgrade python3-perfUpgrade kernel-rt-debugUpgrade kernel-modulesUpgrade kernel-develUpgrade kernel-rt-coreUpgrade kernel-rt-debug-develUpgrade kernel-debug-modulesUpgrade kernel-tools-debuginfoUpgrade kernel-rt-develUpgrade kernel-debug-coreUpgrade kernel-coreUpgrade python3-perf-debuginfoUpgrade kernel-tools-libsUpgrade kernelUpgrade bpftool-debuginfoUpgrade kernel-rt-debuginfo-common-x86_64Upgrade kernel-modules-extraUpgrade perf-debuginfoUpgrade kernel-debug-debuginfoUpgrade kernel-rt-debug-modules-extraUpgrade kernel-rt-debug-kvm | Mar 2, 2026 | Feb 26, 2026 |
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