{"id":"CVE-2026-98455","revision":"8ba4401e659b409eaf61726a75648e2b","records":[{"revision":"8ba4401e659b409eaf61726a75648e2b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98455","aliases":[],"title":"Bluetooth: RFCOMM: fix NULL dereference of dlc->session in RFCOMM_CONNINFO","description":"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.","state":0,"publishedAt":"2026-10-18T15:15:04.988+00:00","modifiedAt":"2026-10-19T09:19:50.74+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/bluetooth/rfcomm/sock.c\"\n ],\n \"versions\": [\n {\n \"version\": \"bb23c0ab824653be4aa7dfca15b07b3059717004\",\n \"lessThan\": \"c3aee3fc1287c8a555baf3895959087cb0c33fe8\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"bb23c0ab824653be4aa7dfca15b07b3059717004\",\n \"lessThan\": \"4bf5ca47203049ce3648f750a53dcdc98bcc9e3e\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"bb23c0ab824653be4aa7dfca15b07b3059717004\",\n \"lessThan\": \"1c4f7e1177da2f229be04139c27e5370a1cfba52\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"bb23c0ab824653be4aa7dfca15b07b3059717004\",\n \"lessThan\": \"84ae3cfd7d3a63591a2eb4faa24faf678c6708aa\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"bb23c0ab824653be4aa7dfca15b07b3059717004\",\n \"lessThan\": \"c7362f6a18ed167f52f08ce25eeec8a7818c5004\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"bb23c0ab824653be4aa7dfca15b07b3059717004\",\n \"lessThan\": \"8f5b30cc12c409ff62891e47ed51e6bf0945a3ea\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"bb23c0ab824653be4aa7dfca15b07b3059717004\",\n \"lessThan\": \"005b23d9e324fe5d0acbcfa70c625f2e81189046\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"bb23c0ab824653be4aa7dfca15b07b3059717004\",\n \"lessThan\": \"46f8ffd0a1f1eb6cbc94946a92c11ef601e228a1\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"net/bluetooth/rfcomm/sock.c\"\n ],\n \"versions\": [\n {\n \"version\": \"2.6.30\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"2.6.30\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.10.271\",\n \"lessThanOrEqual\": \"5.10.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"5.15.222\",\n \"lessThanOrEqual\": \"5.15.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.1.189\",\n \"lessThanOrEqual\": \"6.1.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.6.158\",\n \"lessThanOrEqual\": \"6.6.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.12.112\",\n \"lessThanOrEqual\": \"6.12.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.55\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.9\",\n \"lessThanOrEqual\": \"7.2.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.3\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/c3aee3fc1287c8a555baf3895959087cb0c33fe8","https://git.kernel.org/stable/c/4bf5ca47203049ce3648f750a53dcdc98bcc9e3e","https://git.kernel.org/stable/c/1c4f7e1177da2f229be04139c27e5370a1cfba52","https://git.kernel.org/stable/c/84ae3cfd7d3a63591a2eb4faa24faf678c6708aa","https://git.kernel.org/stable/c/c7362f6a18ed167f52f08ce25eeec8a7818c5004","https://git.kernel.org/stable/c/8f5b30cc12c409ff62891e47ed51e6bf0945a3ea","https://git.kernel.org/stable/c/005b23d9e324fe5d0acbcfa70c625f2e81189046","https://git.kernel.org/stable/c/46f8ffd0a1f1eb6cbc94946a92c11ef601e228a1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98455","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98455","identifiers":["CVE-2026-98455"]},"retained":false,"historicalAffected":[]}],"coverage":[]}