CVE-2025-39983

published 2025-10-15

CVE-2025-39983: In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: Fix UAF in hci_conn_tx_dequeue This fixes the following UAF caused by…

Priority P3 45 high 8.8 CVSS 3.1

AV A AC L PR N UI N S U C H I H A H

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_event: Fix UAF in hci_conn_tx_dequeue

This fixes the following UAF caused by not properly locking hdev when
processing HCI_EV_NUM_COMP_PKTS:

BUG: KASAN: slab-use-after-free in hci_conn_tx_dequeue+0x1be/0x220 net/bluetooth/hci_conn.c:3036
Read of size 4 at addr ffff8880740f0940 by task kworker/u11:0/54

CPU: 1 UID: 0 PID: 54 Comm: kworker/u11:0 Not tainted 6.16.0-rc7 #3 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Workqueue: hci1 hci_rx_work
Call Trace:

dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x230 mm/kasan/report.c:480
kasan_report+0x118/0x150 mm/kasan/report.c:593
hci_conn_tx_dequeue+0x1be/0x220 net/bluetooth/hci_conn.c:3036
hci_num_comp_pkts_evt+0x1c8/0xa50 net/bluetooth/hci_event.c:4404
hci_event_func net/bluetooth/hci_event.c:7477 [inline]
hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531
hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070
process_one_work kernel/workqueue.c:3238 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245

Allocated by task 54:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
__hci_conn_add+0x233/0x1b30 net/bluetooth/hci_conn.c:939
le_conn_complete_evt+0x3d6/0x1220 net/bluetooth/hci_even

Affected

6 ranges

Vendor	Product	Version range	Fixed in
debian	linux	< linux 6.16.10-1 (forky)	linux 6.16.10-1 (forky)
linux	linux	—	—
linux	linux	>= 134f4b39df7b77225a80ef585c15d46f964f5e6f < dde33124f17cf3bab4dc5e18d1b4dee128361061	dde33124f17cf3bab4dc5e18d1b4dee128361061
linux	linux	>= 134f4b39df7b77225a80ef585c15d46f964f5e6f < 2e128683176a56459cef8705fc7c35f438f88abd	2e128683176a56459cef8705fc7c35f438f88abd
linux	linux_kernel	>= 0 < 6.16.10-1	6.16.10-1
linux	linux_kernel	>= 6.15.0 < 6.16.10	6.16.10

CVSS provenance

nvd v3.1 8.8 HIGH CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

vendor_redhat 6.4 MEDIUM

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