CVE-2026-98455

Что произошло

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: fix NULL dereference of dlc->session in RFCOMM_CONNINFO The RFCOMM_CONNINFO getsockopt handler accepts a socket that is not connected as long as deferred setup is enabled: if (sk->sk_state != BT_CONNECTED && !rfcomm_pi(sk)->dlc->defer_setup) { err = -ENOTCONN; break; } l2cap_sk = rfcomm_pi(sk)->dlc->session->sock->sk; dlc->defer_setup is set in rfcomm_sock_init() when rfcomm_connect_ind() creates a child socket for an incoming connection on a listening socket that has BT_DEFER_SETUP enabled. It is never cleared afterwards. The session, however, can go away underneath it. rfcomm_recv_disc() forces the dlc state before tearing it down: d->state = BT_CLOSED; __rfcomm_dlc_close(d, err); The RFCOMM_DEFER_SETUP early return in __rfcomm_dlc_close() only covers BT_CONNECT, BT_CONFIG, BT_OPEN and BT_CONNECT2, so with the state already BT_CLOSED that switch does not match and the function falls through to rfcomm_dlc_unlink(), which sets d->session = NULL, while d->defer_setup stays 1. A getsockopt(SOL_RFCOMM, RFCOMM_CONNINFO) on the accepted socket after that point therefore skips the -ENOTCONN path -- sk->sk_state is BT_CLOSED, but dlc->defer_setup is still set -- and dereferences the NULL session. No race is needed: once the DISC has been processed, the dereference is unconditional. Reproduced on a KASAN kernel under QEMU with a BR/EDR peer emulated over /dev/vhci: the peer brings up an ACL link, opens L2CAP on the RFCOMM PSM, starts a session and sends SABM for a channel bound with BT_DEFER_SETUP, and sends DISC for that dlci after the socket has been accepted. getsockopt(SOL_RFCOMM, RFCOMM_CONNINFO) on the accepted socket then hits: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 UID: 0 PID: 150 Comm: init Tainted: G B 7.3.0-rc3-g5dd1818b15d9 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:rfcomm_sock_getsockopt+0x529/0x780 Call Trace: do_sock_getsockopt+0x3ad/0x7d0 __sys_getsockopt+0x10e/0x1b0 __x64_sys_getsockopt+0xc2/0x160 do_syscall_64+0xda/0x4b0 entry_SYSCALL_64_after_hwframe+0x77/0x7f 0x10 is the offset of sock in struct rfcomm_session; rfcomm_sock_getsockopt_old() is inlined into rfcomm_sock_getsockopt(). Commit 43a556b2fd43 ("Bluetooth: RFCOMM: take rfcomm_mutex for the deferred setup accept") fixed the same "a remote DISC clears the session while deferred setup is still flagged" problem in rfcomm_dlc_accept(); this is the remaining instance of it, in the getsockopt path. Deferred setup only leaves a socket usable here once it has reached BT_CONNECT2, so restrict the exception to that state and check that a session is actually present before following it.

Что делать

dpkg-query -W -f='${Package}	${Version}\n'

rpm -qa --qf '%{NAME}\t%{VERSION}-%{RELEASE}\n'

Get-HotFix | Select-Object HotFixID, InstalledOn

Продукты и затронутые версии

{
  "status": "affected",
  "version": "bb23c0ab824653be4aa7dfca15b07b3059717004",
  "lessThan": "c3aee3fc1287c8a555baf3895959087cb0c33fe8",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "bb23c0ab824653be4aa7dfca15b07b3059717004",
  "lessThan": "4bf5ca47203049ce3648f750a53dcdc98bcc9e3e",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "bb23c0ab824653be4aa7dfca15b07b3059717004",
  "lessThan": "1c4f7e1177da2f229be04139c27e5370a1cfba52",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "bb23c0ab824653be4aa7dfca15b07b3059717004",
  "lessThan": "84ae3cfd7d3a63591a2eb4faa24faf678c6708aa",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "bb23c0ab824653be4aa7dfca15b07b3059717004",
  "lessThan": "c7362f6a18ed167f52f08ce25eeec8a7818c5004",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "bb23c0ab824653be4aa7dfca15b07b3059717004",
  "lessThan": "8f5b30cc12c409ff62891e47ed51e6bf0945a3ea",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "bb23c0ab824653be4aa7dfca15b07b3059717004",
  "lessThan": "005b23d9e324fe5d0acbcfa70c625f2e81189046",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "bb23c0ab824653be4aa7dfca15b07b3059717004",
  "lessThan": "46f8ffd0a1f1eb6cbc94946a92c11ef601e228a1",
  "versionType": "git"
}

{
  "status": "affected",
  "version": "2.6.30"
}

{
  "status": "unaffected",
  "version": "0",
  "lessThan": "2.6.30",
  "versionType": "semver"
}

{
  "status": "unaffected",
  "version": "5.10.271",
  "versionType": "semver",
  "lessThanOrEqual": "5.10.*"
}

{
  "status": "unaffected",
  "version": "5.15.222",
  "versionType": "semver",
  "lessThanOrEqual": "5.15.*"
}

{
  "status": "unaffected",
  "version": "6.1.189",
  "versionType": "semver",
  "lessThanOrEqual": "6.1.*"
}

{
  "status": "unaffected",
  "version": "6.6.158",
  "versionType": "semver",
  "lessThanOrEqual": "6.6.*"
}

{
  "status": "unaffected",
  "version": "6.12.112",
  "versionType": "semver",
  "lessThanOrEqual": "6.12.*"
}

{
  "status": "unaffected",
  "version": "6.18.55",
  "versionType": "semver",
  "lessThanOrEqual": "6.18.*"
}

{
  "status": "unaffected",
  "version": "7.2.9",
  "versionType": "semver",
  "lessThanOrEqual": "7.2.*"
}

{
  "status": "unaffected",
  "version": "7.3",
  "versionType": "original_commit_for_fix",
  "lessThanOrEqual": "*"
}

CVSS: оценки и векторы

Оценка CVSS отсутствует.

Источники и ссылки

{
  "cwes": [],
  "epss": {
    "source": "epss",
    "received_at": "2026-11-01T21:13:21.038354+00:00"
  },
  "title": {
    "source": "cve",
    "received_at": "2026-10-28T20:13:06.425127+00:00"
  },
  "scores": [],
  "status": {
    "source": "cve",
    "received_at": "2026-10-28T20:13:06.425127+00:00"
  },
  "affected": [
    "cve"
  ],
  "published": {
    "source": "cve",
    "received_at": "2026-10-28T20:13:06.425127+00:00"
  },
  "solutions": [],
  "percentile": {
    "source": "epss",
    "received_at": "2026-11-01T21:13:21.038354+00:00"
  },
  "references": [
    "cve"
  ],
  "description": {
    "source": "cve",
    "received_at": "2026-10-28T20:13:06.425127+00:00"
  },
  "workarounds": [],
  "configurations": []
}

Хронология записи

1. Данные обновлены02.11.2026, 00:13
2. Данные обновлены31.10.2026, 12:00
3. Данные обновлены29.10.2026, 12:47
4. Опубликована28.10.2026, 23:13

Личная заметка и статус

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