CVE-2026-98737 (GCVE-0-2026-98737)
Vulnerability from cvelistv5
Published
2026-10-18 15:47
Modified
2026-10-21 12:56
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: Fix inquiry cache use-after-free The sync command worker holds hdev->req_lock, but inquiry-cache updates and flushes use hdev->lock. Both hci_acl_create_conn_sync() and hci_stop_discovery_sync() look up entries and read their fields without taking hdev->lock. After either lookup returns, a concurrent HCIINQUIRY ioctl can acquire hdev->lock and flush the cache, freeing the entry. The worker then reads the freed entry while preparing a create-connection or remote-name-cancel command. The list traversal also races with cache updates and removal. KASAN reported these accesses: BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0x5f1/0x650 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_acl_create_conn_sync+0x5f1/0x650 hci_cmd_sync_work+0x13c/0x290 Allocated by task 90: hci_inquiry_cache_update+0x3e6/0x7d0 hci_inquiry_result_evt+0x3cb/0x560 Freed by task 93: hci_inquiry_cache_flush+0x111/0x2b0 hci_inquiry+0x2f2/0x780 hci_sock_ioctl+0x269/0x5f0 BUG: KASAN: slab-use-after-free in hci_stop_discovery_sync+0x3b1/0x3c0 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_stop_discovery_sync+0x3b1/0x3c0 hci_cmd_sync_work+0x173/0x300 Allocated by task 86: hci_inquiry_cache_update+0x483/0x940 hci_inquiry_result_evt+0x3cb/0x560 Freed by task 91: hci_inquiry_cache_flush+0x13e/0x2f0 hci_inquiry+0x2f2/0x780 hci_sock_ioctl+0x269/0x5f0 Hold hdev->lock across each lookup and all reads from its result. Copy the remote address before unlocking so discovery cancellation does not retain a cache entry pointer. Release the lock before sending synchronous HCI commands, since their completion handlers may need the same lock.
References
Impacted products
Vendor Product Version
Linux Linux Version: cf75ad8b41d2aa06f98f365d42a3ae8b059daddd
Version: cf75ad8b41d2aa06f98f365d42a3ae8b059daddd
Version: cf75ad8b41d2aa06f98f365d42a3ae8b059daddd
Version: cf75ad8b41d2aa06f98f365d42a3ae8b059daddd
Version: cf75ad8b41d2aa06f98f365d42a3ae8b059daddd
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/hci_sync.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/hci_sync.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "lessThan": "5.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.160",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionEndExcluding": "6.12.113",
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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              ],
              "negate": false,
              "operator": "OR"
            }
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        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: Fix inquiry cache use-after-free\n\nThe sync command worker holds hdev-\u003ereq_lock, but inquiry-cache updates\nand flushes use hdev-\u003elock. Both hci_acl_create_conn_sync() and\nhci_stop_discovery_sync() look up entries and read their fields without\ntaking hdev-\u003elock.\n\nAfter either lookup returns, a concurrent HCIINQUIRY ioctl can acquire\nhdev-\u003elock and flush the cache, freeing the entry. The worker then reads\nthe freed entry while preparing a create-connection or remote-name-cancel\ncommand. The list traversal also races with cache updates and removal.\n\nKASAN reported these accesses:\n\n  BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0x5f1/0x650\n  Workqueue: hci0 hci_cmd_sync_work\n  Call Trace:\n   hci_acl_create_conn_sync+0x5f1/0x650\n   hci_cmd_sync_work+0x13c/0x290\n\n  Allocated by task 90:\n   hci_inquiry_cache_update+0x3e6/0x7d0\n   hci_inquiry_result_evt+0x3cb/0x560\n\n  Freed by task 93:\n   hci_inquiry_cache_flush+0x111/0x2b0\n   hci_inquiry+0x2f2/0x780\n   hci_sock_ioctl+0x269/0x5f0\n\n  BUG: KASAN: slab-use-after-free in hci_stop_discovery_sync+0x3b1/0x3c0\n  Workqueue: hci0 hci_cmd_sync_work\n  Call Trace:\n   hci_stop_discovery_sync+0x3b1/0x3c0\n   hci_cmd_sync_work+0x173/0x300\n\n  Allocated by task 86:\n   hci_inquiry_cache_update+0x483/0x940\n   hci_inquiry_result_evt+0x3cb/0x560\n\n  Freed by task 91:\n   hci_inquiry_cache_flush+0x13e/0x2f0\n   hci_inquiry+0x2f2/0x780\n   hci_sock_ioctl+0x269/0x5f0\n\nHold hdev-\u003elock across each lookup and all reads from its result. Copy the\nremote address before unlocking so discovery cancellation does not retain\na cache entry pointer. Release the lock before sending synchronous HCI\ncommands, since their completion handlers may need the same lock."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:56:13.421Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ddc9edb244cc8b5266595e8fc220e7813f2b603a"
        },
        {
          "url": "https://git.kernel.org/stable/c/52edf1c0e59dea37b8368c4a2559dca96b2fdfea"
        },
        {
          "url": "https://git.kernel.org/stable/c/333257e6e4a7bcaaea82fd357121d0f1e6b76c7b"
        },
        {
          "url": "https://git.kernel.org/stable/c/a642f498f0b08f2aa9f4a69468db92f57a72349d"
        },
        {
          "url": "https://git.kernel.org/stable/c/8ed67535fdff40ca652bcd4ac7da68d11d01bd34"
        }
      ],
      "title": "Bluetooth: hci_sync: Fix inquiry cache use-after-free",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98737",
    "datePublished": "2026-10-18T15:47:14.936Z",
    "dateReserved": "2026-09-25T10:25:14.367Z",
    "dateUpdated": "2026-10-21T12:56:13.421Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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