Bluetooth: hci_core: Serialize fragmented ISO packet queueing
The fragmented path in hci_queue_iso() calls __skb_queue_tail() without
holding conn->data_q.lock. The socket lock serializes senders, but the
transmit worker can concurrently remove packets from this queue using
skb_dequeue().
After an insertion saves the old tail pointer, hci_sched_iso() can dequeue
that packet and pass it to the driver. The driver can free the packet
before the insertion resumes and writes to the old tail's next pointer,
causing a use-after-free. Concurrent updates can also corrupt the queue.
KASAN reported:
BUG: KASAN: slab-use-after-free in hci_send_iso+0xc7d/0xe10
Call Trace:
hci_send_iso+0xc7d/0xe10
iso_sock_sendmsg+0x710/0x900
__sys_sendto+0x34a/0x3a0
Allocated by task 86:
__alloc_skb+0xdd/0x820
alloc_skb_with_frags+0x7e/0x770
sock_alloc_send_pskb+0x67a/0x820
bt_skb_sendmsg.constprop.0+0xc0/0x6c0
iso_sock_sendmsg+0x44e/0x900
Freed by task 90:
kmem_cache_free+0xcb/0x3d0
vhci_read+0x33f/0x4d0
vfs_read+0x177/0xa20
Hold the queue lock across the entire fragment batch, as hci_queue_acl()
does, to serialize insertion against dequeue while preserving fragment
ordering.
Analysis
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Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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No data.
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No data available yet.
No vendor fix or workaround currently provided.
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Sun, 18 Oct 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Serialize fragmented ISO packet queueing The fragmented path in hci_queue_iso() calls __skb_queue_tail() without holding conn->data_q.lock. The socket lock serializes senders, but the transmit worker can concurrently remove packets from this queue using skb_dequeue(). After an insertion saves the old tail pointer, hci_sched_iso() can dequeue that packet and pass it to the driver. The driver can free the packet before the insertion resumes and writes to the old tail's next pointer, causing a use-after-free. Concurrent updates can also corrupt the queue. KASAN reported: BUG: KASAN: slab-use-after-free in hci_send_iso+0xc7d/0xe10 Call Trace: hci_send_iso+0xc7d/0xe10 iso_sock_sendmsg+0x710/0x900 __sys_sendto+0x34a/0x3a0 Allocated by task 86: __alloc_skb+0xdd/0x820 alloc_skb_with_frags+0x7e/0x770 sock_alloc_send_pskb+0x67a/0x820 bt_skb_sendmsg.constprop.0+0xc0/0x6c0 iso_sock_sendmsg+0x44e/0x900 Freed by task 90: kmem_cache_free+0xcb/0x3d0 vhci_read+0x33f/0x4d0 vfs_read+0x177/0xa20 Hold the queue lock across the entire fragment batch, as hci_queue_acl() does, to serialize insertion against dequeue while preserving fragment ordering. | |
| Title | Bluetooth: hci_core: Serialize fragmented ISO packet queueing | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-18T15:47:11.210Z
Reserved: 2026-09-25T10:25:14.367Z
Link: CVE-2026-98733
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T16:17:26.900
Modified: 2026-10-18T16:17:26.900
Link: CVE-2026-98733
Redhat
No data.
OpenCVE Enrichment
No data.
No weakness.