Bluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan
l2cap_new_connection() sets default value of channel mode to match the
parent channel. l2cap_le_connect_req() left this at the default, and
created L2CAP_MODE_EXT_FLOWCTL channels if listening pchan has that
mode. This causes FLAG_DEFER_SETUP channels to reply to
L2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect.
It can also result to stack OOB write (of l2cap_alloc_cid determined
values) in l2cap_ecred_rsp_defer(), as l2cap_le_connect_req() does not
limit maximum number of deferred channels or check for duplicate ident.
Fix by setting chan->mode correctly in l2cap_le_connect_req().
Also check channel mode in l2cap_ecred_rsp_defer(), and do WARN_ON_ONCE
instead of OOB write to make it less brittle.
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4817-1 | linux-6.12 security update |
Debian DLA |
DLA-4841-1 | linux security update |
Debian DSA |
DSA-6528-1 | linux security update |
Ubuntu USN |
USN-8961-1 | Linux kernel vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Sat, 03 Oct 2026 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
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Tue, 29 Sep 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-787 | |
| References |
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| Metrics |
threat_severity
|
threat_severity
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Fri, 25 Sep 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-787 |
Fri, 25 Sep 2026 17:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-787 |
Fri, 25 Sep 2026 15:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
cvssV3_1
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Fri, 25 Sep 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan l2cap_new_connection() sets default value of channel mode to match the parent channel. l2cap_le_connect_req() left this at the default, and created L2CAP_MODE_EXT_FLOWCTL channels if listening pchan has that mode. This causes FLAG_DEFER_SETUP channels to reply to L2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect. It can also result to stack OOB write (of l2cap_alloc_cid determined values) in l2cap_ecred_rsp_defer(), as l2cap_le_connect_req() does not limit maximum number of deferred channels or check for duplicate ident. Fix by setting chan->mode correctly in l2cap_le_connect_req(). Also check channel mode in l2cap_ecred_rsp_defer(), and do WARN_ON_ONCE instead of OOB write to make it less brittle. | |
| Title | Bluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-19T09:14:00.739Z
Reserved: 2026-09-25T10:25:14.316Z
Link: CVE-2026-98108
No data.
Status : Undergoing Analysis
Published: 2026-09-25T11:17:41.863
Modified: 2026-10-19T10:18:08.400
Link: CVE-2026-98108
OpenCVE Enrichment
Updated: 2026-09-30T06:00:12Z
Debian DLA
Debian DSA
Ubuntu USN