{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98455", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.350Z", "datePublished": "2026-10-18T15:15:04.988Z", "dateUpdated": "2026-10-19T09:19:50.740Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:19:50.740Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: fix NULL dereference of dlc->session in RFCOMM_CONNINFO\n\nThe RFCOMM_CONNINFO getsockopt handler accepts a socket that is not\nconnected as long as deferred setup is enabled:\n\n\tif (sk->sk_state != BT_CONNECTED &&\n\t\t\t\t!rfcomm_pi(sk)->dlc->defer_setup) {\n\t\terr = -ENOTCONN;\n\t\tbreak;\n\t}\n\tl2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk;\n\ndlc->defer_setup is set in rfcomm_sock_init() when rfcomm_connect_ind()\ncreates a child socket for an incoming connection on a listening socket\nthat has BT_DEFER_SETUP enabled. It is never cleared afterwards. The\nsession, however, can go away underneath it.\n\nrfcomm_recv_disc() forces the dlc state before tearing it down:\n\n\td->state = BT_CLOSED;\n\t__rfcomm_dlc_close(d, err);\n\nThe RFCOMM_DEFER_SETUP early return in __rfcomm_dlc_close() only covers\nBT_CONNECT, BT_CONFIG, BT_OPEN and BT_CONNECT2, so with the state\nalready BT_CLOSED that switch does not match and the function falls\nthrough to rfcomm_dlc_unlink(), which sets d->session = NULL, while\nd->defer_setup stays 1.\n\nA getsockopt(SOL_RFCOMM, RFCOMM_CONNINFO) on the accepted socket after\nthat point therefore skips the -ENOTCONN path -- sk->sk_state is\nBT_CLOSED, but dlc->defer_setup is still set -- and dereferences the\nNULL session. No race is needed: once the DISC has been processed, the\ndereference is unconditional.\n\nReproduced on a KASAN kernel under QEMU with a BR/EDR peer emulated over\n/dev/vhci: the peer brings up an ACL link, opens L2CAP on the RFCOMM\nPSM, starts a session and sends SABM for a channel bound with\nBT_DEFER_SETUP, and sends DISC for that dlci after the socket has been\naccepted. getsockopt(SOL_RFCOMM, RFCOMM_CONNINFO) on the accepted\nsocket then hits:\n\n Oops: general protection fault, probably for non-canonical address\n 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI\n KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\n CPU: 1 UID: 0 PID: 150 Comm: init Tainted: G B 7.3.0-rc3-g5dd1818b15d9\n Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)\n RIP: 0010:rfcomm_sock_getsockopt+0x529/0x780\n Call Trace:\n \n do_sock_getsockopt+0x3ad/0x7d0\n __sys_getsockopt+0x10e/0x1b0\n __x64_sys_getsockopt+0xc2/0x160\n do_syscall_64+0xda/0x4b0\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n \n\n0x10 is the offset of sock in struct rfcomm_session;\nrfcomm_sock_getsockopt_old() is inlined into rfcomm_sock_getsockopt().\n\nCommit 43a556b2fd43 (\"Bluetooth: RFCOMM: take rfcomm_mutex for the\ndeferred setup accept\") fixed the same \"a remote DISC clears the session\nwhile deferred setup is still flagged\" problem in rfcomm_dlc_accept();\nthis is the remaining instance of it, in the getsockopt path.\n\nDeferred setup only leaves a socket usable here once it has reached\nBT_CONNECT2, so restrict the exception to that state and check that a\nsession is actually present before following it." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/rfcomm/sock.c" ], "versions": [ { "version": "bb23c0ab824653be4aa7dfca15b07b3059717004", "lessThan": "c3aee3fc1287c8a555baf3895959087cb0c33fe8", "status": "affected", "versionType": "git" }, { "version": "bb23c0ab824653be4aa7dfca15b07b3059717004", "lessThan": "4bf5ca47203049ce3648f750a53dcdc98bcc9e3e", "status": "affected", "versionType": "git" }, { "version": "bb23c0ab824653be4aa7dfca15b07b3059717004", "lessThan": "1c4f7e1177da2f229be04139c27e5370a1cfba52", "status": "affected", "versionType": "git" }, { "version": "bb23c0ab824653be4aa7dfca15b07b3059717004", "lessThan": "84ae3cfd7d3a63591a2eb4faa24faf678c6708aa", "status": "affected", "versionType": "git" }, { "version": "bb23c0ab824653be4aa7dfca15b07b3059717004", "lessThan": "c7362f6a18ed167f52f08ce25eeec8a7818c5004", "status": "affected", "versionType": "git" }, { "version": "bb23c0ab824653be4aa7dfca15b07b3059717004", "lessThan": "8f5b30cc12c409ff62891e47ed51e6bf0945a3ea", "status": "affected", "versionType": "git" }, { "version": "bb23c0ab824653be4aa7dfca15b07b3059717004", "lessThan": "005b23d9e324fe5d0acbcfa70c625f2e81189046", "status": "affected", "versionType": "git" }, { "version": "bb23c0ab824653be4aa7dfca15b07b3059717004", "lessThan": "46f8ffd0a1f1eb6cbc94946a92c11ef601e228a1", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/rfcomm/sock.c" ], "versions": [ { "version": "2.6.30", "status": "affected" }, { "version": "0", "lessThan": "2.6.30", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.55", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.9", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "5.10.271" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.18.55" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "7.2.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c3aee3fc1287c8a555baf3895959087cb0c33fe8" }, { "url": "https://git.kernel.org/stable/c/4bf5ca47203049ce3648f750a53dcdc98bcc9e3e" }, { "url": "https://git.kernel.org/stable/c/1c4f7e1177da2f229be04139c27e5370a1cfba52" }, { "url": "https://git.kernel.org/stable/c/84ae3cfd7d3a63591a2eb4faa24faf678c6708aa" }, { "url": "https://git.kernel.org/stable/c/c7362f6a18ed167f52f08ce25eeec8a7818c5004" }, { "url": "https://git.kernel.org/stable/c/8f5b30cc12c409ff62891e47ed51e6bf0945a3ea" }, { "url": "https://git.kernel.org/stable/c/005b23d9e324fe5d0acbcfa70c625f2e81189046" }, { "url": "https://git.kernel.org/stable/c/46f8ffd0a1f1eb6cbc94946a92c11ef601e228a1" } ], "title": "Bluetooth: RFCOMM: fix NULL dereference of dlc->session in RFCOMM_CONNINFO", "x_generator": { "engine": "bippy-1.2.0" } } } }