{"api_version":"1","generated_at":"2026-10-21T18:43:06+00:00","cve":"CVE-2026-98739","urls":{"html":"https://cve.report/CVE-2026-98739","api":"https://cve.report/api/cve/CVE-2026-98739.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98739","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98739"},"summary":{"title":"Bluetooth: RFCOMM: Fix initial port reference race","description":"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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:17:27","updated_at":"2026-10-21 13:21:41"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/2d696c1ed3468dcb62578a3911e687110d463520","name":"https://git.kernel.org/stable/c/2d696c1ed3468dcb62578a3911e687110d463520","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0a554901bd227537f79220443b2b36d585d62893","name":"https://git.kernel.org/stable/c/0a554901bd227537f79220443b2b36d585d62893","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b","name":"https://git.kernel.org/stable/c/e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a03ccf1ab77380d4c4a3c56552e12de4a83efa21","name":"https://git.kernel.org/stable/c/a03ccf1ab77380d4c4a3c56552e12de4a83efa21","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/55d162aa00d1ee33c3e6fa88b71f1e2d6e1441e9","name":"https://git.kernel.org/stable/c/55d162aa00d1ee33c3e6fa88b71f1e2d6e1441e9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98739","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98739","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 80ea73378af46b0023eb2f400d26c2a60248ffaa 55d162aa00d1ee33c3e6fa88b71f1e2d6e1441e9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 80ea73378af46b0023eb2f400d26c2a60248ffaa a03ccf1ab77380d4c4a3c56552e12de4a83efa21 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 80ea73378af46b0023eb2f400d26c2a60248ffaa 0a554901bd227537f79220443b2b36d585d62893 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 80ea73378af46b0023eb2f400d26c2a60248ffaa e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 80ea73378af46b0023eb2f400d26c2a60248ffaa 2d696c1ed3468dcb62578a3911e687110d463520 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 3.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.160 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.113 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.56 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.10 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/bluetooth/rfcomm/tty.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"55d162aa00d1ee33c3e6fa88b71f1e2d6e1441e9","status":"affected","version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","versionType":"git"},{"lessThan":"a03ccf1ab77380d4c4a3c56552e12de4a83efa21","status":"affected","version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","versionType":"git"},{"lessThan":"0a554901bd227537f79220443b2b36d585d62893","status":"affected","version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","versionType":"git"},{"lessThan":"e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b","status":"affected","version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","versionType":"git"},{"lessThan":"2d696c1ed3468dcb62578a3911e687110d463520","status":"affected","version":"80ea73378af46b0023eb2f400d26c2a60248ffaa","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/bluetooth/rfcomm/tty.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.15"},{"lessThan":"3.15","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":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.160","versionStartIncluding":"3.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.113","versionStartIncluding":"3.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.56","versionStartIncluding":"3.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.10","versionStartIncluding":"3.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"3.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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."}],"providerMetadata":{"dateUpdated":"2026-10-21T12:56:15.633Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/55d162aa00d1ee33c3e6fa88b71f1e2d6e1441e9"},{"url":"https://git.kernel.org/stable/c/a03ccf1ab77380d4c4a3c56552e12de4a83efa21"},{"url":"https://git.kernel.org/stable/c/0a554901bd227537f79220443b2b36d585d62893"},{"url":"https://git.kernel.org/stable/c/e5aa7fbf7a4446bb89f0b8394b2dfc1a6b6aba5b"},{"url":"https://git.kernel.org/stable/c/2d696c1ed3468dcb62578a3911e687110d463520"}],"title":"Bluetooth: RFCOMM: Fix initial port reference race","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98739","datePublished":"2026-10-18T15:47:23.653Z","dateReserved":"2026-09-25T10:25:14.367Z","dateUpdated":"2026-10-21T12:56:15.633Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:17:27","lastModifiedDate":"2026-10-21 13:21:41","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98739","Ordinal":"1","Title":"Bluetooth: RFCOMM: Fix initial port reference race","CVE":"CVE-2026-98739","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98739","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Bluetooth: RFCOMM: Fix initial port reference race"}]}}}