{"schema":"threatline.record/2","record":{"id":"CVE-2026-98739","aliases":[],"summary":"Bluetooth: RFCOMM: Fix initial port reference race","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: Fix initial port reference race\n\nFor RFCOMM_RELEASE_ONHUP devices, rfcomm_tty_install() and\n__rfcomm_release_dev() both use RFCOMM_TTY_OWNED to decide who drops the\ninitial tty_port reference. The release path tests the bit separately\nfrom the install path setting it, so both can drop that reference.\n\nThe synchronous hangup does not prevent this race: port->tty is not\nassigned until tty_port_open(), after installation. The following\ninterleaving is possible:\n\n  1. Install and release each obtain a reference with rfcomm_dev_get().\n  2. Release observes RFCOMM_TTY_OWNED clear.\n  3. Install sets RFCOMM_TTY_OWNED and drops the initial reference.\n  4. Release drops the same initial reference again.\n  5. TTY cleanup drops its reference and frees the device.\n  6. Release performs its final tty_port_put() on the freed port.\n\nKASAN reported:\n\n  BUG: KASAN: slab-use-after-free in tty_port_put+0x22/0x190\n  Write of size 4 at addr ffff8881001d3d5c by task poc/92\n\n  Call Trace:\n   tty_port_put+0x22/0x190\n   rfcomm_dev_ioctl+0x1d4/0x1930\n   sock_do_ioctl+0x110/0x260\n   sock_ioctl+0x380/0x590\n   __x64_sys_ioctl+0x134/0x1c0\n\n  Allocated by task 88:\n   rfcomm_dev_ioctl+0x8f6/0x1930\n   sock_do_ioctl+0x110/0x260\n   sock_ioctl+0x380/0x590\n   __x64_sys_ioctl+0x134/0x1c0\n\n  Freed by task 65:\n   kfree+0x131/0x3c0\n   rfcomm_dev_destruct+0x23b/0x2f0\n   release_one_tty+0xc1/0x370\n   process_one_work+0x661/0x1090\n\nUse test_and_set_bit() in both paths so that only the caller that changes\nRFCOMM_TTY_OWNED from clear to set drops the initial reference. Each path\nkeeps its own lookup reference until release or TTY cleanup, preserving\nthe existing callback ordering and error handling.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98739","source_modified_at":"2026-10-21T12:56:15.633Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","lessThan":"55d162aa00d1ee33c3e6fa88b71f1e2d6e1441e9","status":"affected","versionType":"git"},{"version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","lessThan":"a03ccf1ab77380d4c4a3c56552e12de4a83efa21","status":"affected","versionType":"git"},{"version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","lessThan":"0a554901bd227537f79220443b2b36d585d62893","status":"affected","versionType":"git"},{"version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","lessThan":"e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b","status":"affected","versionType":"git"},{"version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","lessThan":"2d696c1ed3468dcb62578a3911e687110d463520","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98739","source_modified_at":"2026-10-21T12:56:15.633Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"3.15","status":"affected"},{"version":"0","lessThan":"3.15","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.113","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.56","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.10","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98739","source_modified_at":"2026-10-21T12:56:15.633Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"55d162aa00d1ee33c3e6fa88b71f1e2d6e1441e9","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98739","source_modified_at":"2026-10-21T12:56:15.633Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"0a554901bd227537f79220443b2b36d585d62893","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98739","source_modified_at":"2026-10-21T12:56:15.633Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"2d696c1ed3468dcb62578a3911e687110d463520","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00168,"percentile":0.05734,"score_date":"2026-10-23"},"published_at":"2026-10-18T15:47:23.653Z","modified_at":"2026-10-21T12:56:15.633Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98739","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T12:56:15.633Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98739","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/55d162aa00d1ee33c3e6fa88b71f1e2d6e1441e9"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/a03ccf1ab77380d4c4a3c56552e12de4a83efa21"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/0a554901bd227537f79220443b2b36d585d62893"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/2d696c1ed3468dcb62578a3911e687110d463520"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-21T12:56:15.633Z","content_hash":"3718b9b0ff28746115f2c438760e035e306fa975006eedd364fca8d2c7e0d689"}}