Security Vulnerability Report
中文
CVE-2026-31500 CVSS 7.8 HIGH

CVE-2026-31500

Published: 2026-04-22 14:16:48
Last Modified: 2026-04-28 13:57:58
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btintel: serialize btintel_hw_error() with hci_req_sync_lock btintel_hw_error() issues two __hci_cmd_sync() calls (HCI_OP_RESET and Intel exception-info retrieval) without holding hci_req_sync_lock(). This lets it race against hci_dev_do_close() -> btintel_shutdown_combined(), which also runs __hci_cmd_sync() under the same lock. When both paths manipulate hdev->req_status/req_rsp concurrently, the close path may free the response skb first, and the still-running hw_error path hits a slab-use-after-free in kfree_skb(). Wrap the whole recovery sequence in hci_req_sync_lock/unlock so it is serialized with every other synchronous HCI command issuer. Below is the data race report and the kasan report: BUG: data-race in __hci_cmd_sync_sk / btintel_shutdown_combined read of hdev->req_rsp at net/bluetooth/hci_sync.c:199 by task kworker/u17:1/83: __hci_cmd_sync_sk+0x12f2/0x1c30 net/bluetooth/hci_sync.c:200 __hci_cmd_sync+0x55/0x80 net/bluetooth/hci_sync.c:223 btintel_hw_error+0x114/0x670 drivers/bluetooth/btintel.c:254 hci_error_reset+0x348/0xa30 net/bluetooth/hci_core.c:1030 write/free by task ioctl/22580: btintel_shutdown_combined+0xd0/0x360 drivers/bluetooth/btintel.c:3648 hci_dev_close_sync+0x9ae/0x2c10 net/bluetooth/hci_sync.c:5246 hci_dev_do_close+0x232/0x460 net/bluetooth/hci_core.c:526 BUG: KASAN: slab-use-after-free in sk_skb_reason_drop+0x43/0x380 net/core/skbuff.c:1202 Read of size 4 at addr ffff888144a738dc by task kworker/u17:1/83: __hci_cmd_sync_sk+0x12f2/0x1c30 net/bluetooth/hci_sync.c:200 __hci_cmd_sync+0x55/0x80 net/bluetooth/hci_sync.c:223 btintel_hw_error+0x186/0x670 drivers/bluetooth/btintel.c:260

CVSS Details

CVSS Score
7.8
Severity
HIGH
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* - VULNERABLE
cpe:2.3:o:linux:linux_kernel:4.3:-:*:*:*:*:*:* - VULNERABLE
Linux Kernel < 6.1 (commit 5f84e845648d)
Linux Kernel < 6.6 (commit 66696648af47)
Linux Kernel < 6.8 (commit 94d8e6fe5d08)
Linux Kernel < 6.9 (commit e10a4cb72468)
Linux Kernel < 6.10-rc1 (commit f7d84737663a)

PoC / Exploit Code

⚠ For Security Research Only
The following code is for security research and authorized testing only.
python
// This is a conceptual PoC to trigger the race condition. // It requires a vulnerable Intel Bluetooth device. #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <fcntl.h> #include <sys/ioctl.h> #define HCIDEVDOWN 0x400448CA void trigger_hw_error(int sock) { // Simulate triggering the hardware error path // In a real scenario, this might involve specific socket operations // or manipulating the device state to invoke btintel_hw_error(). printf("[+] Attempting to trigger hardware error path...\n"); // ... specific ioctl or socket send ... } void close_device(int dev_id) { int ctl = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI); if (ctl < 0) return; // Bring device down to trigger btintel_shutdown_combined if (ioctl(ctl, HCIDEVDOWN, dev_id) < 0) { perror("ioctl"); } close(ctl); } int main() { // Setup: Open Bluetooth socket and get device ID // ... (omitted for brevity) ... int dev_id = 0; printf("[+] Starting Race Condition Exploit for CVE-2026-31500\n"); // Fork to race if (fork() == 0) { while(1) trigger_hw_error(0); } else { while(1) close_device(dev_id); } return 0; }

References

Raw JSON Data

JSON
{"cve": {"id": "CVE-2026-31500", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-04-22T14:16:48.427", "lastModified": "2026-04-28T13:57:57.787", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: btintel: serialize btintel_hw_error() with hci_req_sync_lock\n\nbtintel_hw_error() issues two __hci_cmd_sync() calls (HCI_OP_RESET\nand Intel exception-info retrieval) without holding\nhci_req_sync_lock(). This lets it race against\nhci_dev_do_close() -> btintel_shutdown_combined(), which also runs\n__hci_cmd_sync() under the same lock. When both paths manipulate\nhdev->req_status/req_rsp concurrently, the close path may free the\nresponse skb first, and the still-running hw_error path hits a\nslab-use-after-free in kfree_skb().\n\nWrap the whole recovery sequence in hci_req_sync_lock/unlock so it\nis serialized with every other synchronous HCI command issuer.\n\nBelow is the data race report and the kasan report:\n\n BUG: data-race in __hci_cmd_sync_sk / btintel_shutdown_combined\n\n read of hdev->req_rsp at net/bluetooth/hci_sync.c:199\n by task kworker/u17:1/83:\n __hci_cmd_sync_sk+0x12f2/0x1c30 net/bluetooth/hci_sync.c:200\n __hci_cmd_sync+0x55/0x80 net/bluetooth/hci_sync.c:223\n btintel_hw_error+0x114/0x670 drivers/bluetooth/btintel.c:254\n hci_error_reset+0x348/0xa30 net/bluetooth/hci_core.c:1030\n\n write/free by task ioctl/22580:\n btintel_shutdown_combined+0xd0/0x360\n drivers/bluetooth/btintel.c:3648\n hci_dev_close_sync+0x9ae/0x2c10 net/bluetooth/hci_sync.c:5246\n hci_dev_do_close+0x232/0x460 net/bluetooth/hci_core.c:526\n\n BUG: KASAN: slab-use-after-free in\n sk_skb_reason_drop+0x43/0x380 net/core/skbuff.c:1202\n Read of size 4 at addr ffff888144a738dc\n by task kworker/u17:1/83:\n __hci_cmd_sync_sk+0x12f2/0x1c30 net/bluetooth/hci_sync.c:200\n __hci_cmd_sync+0x55/0x80 net/bluetooth/hci_sync.c:223\n btintel_hw_error+0x186/0x670 drivers/bluetooth/btintel.c:260"}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-416"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.3.1", "versionEndExcluding": "6.6.131", "matchCriteriaId": "13A272C2-FFCB-4269-8944-00DFA555EB6F"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.80", "matchCriteriaId": "97EB19EC-A11E-49C6-9D2F-6F6EC6CB98B6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.21", "matchCriteriaId": "ED39847A-3B46-4729-B7CA-B2C30B9FA8FE"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.11", "matchCriteriaId": "4CA2E747-A9EC-4518-9AA2-B4247FC748B7"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:4.3:-:*:*:*:*:*:*", "matchCriteriaId": "5419A247-F671-44D6-9848-35264FDCD816"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/5f84e845648dfa86e42de5487f1a774b42f0444d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/66696648af477dc87859e5e4b607112f5f29 ... (truncated)