CVE-2026-31393

HIGH

Bluetooth: L2CAP: Validate L2CAP_INFO_RSP payload length before access

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Validate L2CAP_INFO_RSP payload length before access l2cap_information_rsp() checks that cmd_len covers the fixed l2cap_info_rsp header (type + result, 4 bytes) but then reads rsp->data without verifying that the payload is present: - L2CAP_IT_FEAT_MASK calls get_unaligned_le32(rsp->data), which reads 4 bytes past the header (needs cmd_len >= 8). - L2CAP_IT_FIXED_CHAN reads rsp->data[0], 1 byte past the header (needs cmd_len >= 5). A truncated L2CAP_INFO_RSP with result == L2CAP_IR_SUCCESS triggers an out-of-bounds read of adjacent skb data. Guard each data access with the required payload length check. If the payload is too short, skip the read and let the state machine complete with safe defaults (feat_mask and remote_fixed_chan remain zero from kzalloc), so the info timer cleanup and l2cap_conn_start() still run and the connection is not stalled.

Scores

CVSS v3 8.1
EPSS 0.0006
EPSS Percentile 18.6%
Attack Vector ADJACENT_NETWORK
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Details

Status published
Products (19)
Linux/Linux < 2.6.24
Linux/Linux 2.6.24
Linux/Linux 4e8402a3f884427f9233ba436459c158d1f2e114 - 187e6fe939295be36063a1d91f8bebee04399a8c
Linux/Linux 4e8402a3f884427f9233ba436459c158d1f2e114 - 3b646516cba2ebc4b51a72954903326e7c1e443f
Linux/Linux 4e8402a3f884427f9233ba436459c158d1f2e114 - 5229e7d15771eac2b5886bfb1f976aea0c1eec14
Linux/Linux 4e8402a3f884427f9233ba436459c158d1f2e114 - 807bd1258453c4c83f6ae9dbc1e7b44860ff40d0
Linux/Linux 4e8402a3f884427f9233ba436459c158d1f2e114 - 9aeacde4da0f02d42fd968fd32f245828b230171
Linux/Linux 4e8402a3f884427f9233ba436459c158d1f2e114 - db2872d054e467810078e2b9f440a5b326a601b2
Linux/Linux 4e8402a3f884427f9233ba436459c158d1f2e114 - dd815e6e3918dc75a49aaabac36e4f024d675101
Linux/Linux 4e8402a3f884427f9233ba436459c158d1f2e114 - e7ff754e339e3d5ce29aa9f95352d0186df8fbd9
... and 9 more
Published Apr 03, 2026
Tracked Since Apr 03, 2026