{"id":"CVE-2026-99013","state":"PUBLISHED","title":"Bluetooth: ISO: Reject concurrent BIS listener setup","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: Reject concurrent BIS listener setup\n\niso_sock_listen() drops the socket lock before calling iso_listen_bis()\nto preserve the hdev->lock ordering. Two concurrent listen() calls on\nthe same broadcast socket can therefore both observe BT_BOUND. Caller\nA can attach connA and release the locks, then caller B can acquire\nthem and attach connB before A publishes BT_LISTEN.\n\n__iso_chan_add() checks whether connB already has a socket, but not\nwhether the socket already has a connection. The second attachment\noverwrites iso_pi(sk)->conn, leaking the connA reference and leaving\nconnA->sk intact. Socket teardown follows connB, so later events on\nconnA can cause a stale socket access.\n\nRecheck BT_BOUND and require iso_pi(sk)->conn to be NULL after taking\nboth the HCI device and socket locks in iso_listen_bis(). The connection\ncheck also covers the interval between attachment and publication of\nBT_LISTEN. Reject a competing setup with -EBADFD through the existing\nunlock path before allocating another connection.\n\nA recorded KASAN report from an instrumented kernel shows:\n\n  BUG: KASAN: slab-use-after-free in iso_sock_hold+0x119/0x1f0\n  Call Trace:\n   iso_sock_hold+0x119/0x1f0\n   iso_conn_del+0xe4/0x270\n   hci_disconn_complete_evt+0x351/0x8c0\n   hci_event_packet+0x71b/0xb20\n   hci_rx_work+0x293/0x730\n\n  Allocated by task 93:\n   sk_prot_alloc+0x113/0x220\n   sk_alloc+0x2b/0x6d0\n   bt_sock_alloc+0x29/0x370\n   iso_sock_alloc.constprop.0+0x19/0x300\n   iso_sock_create+0x94/0x100\n\n  Freed by task 93:\n   kfree+0x121/0x3c0\n   __sk_destruct+0x42b/0x540\n   iso_sock_release+0x29d/0x340\n   __sock_release+0xa1/0x260\n   sock_close+0x10/0x20","publishedAt":"2026-10-23T12:20:38.612Z","updatedAt":"2026-10-24T14:10:01.562Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c541d7b5e17987ed330798b07d4ad508859c1c93","status":"affected","lessThan":"559e4d2b6f83aaa96061659cc7104b7a0293f9ef","versionType":"git"},{"version":"168e28305b871d8ec604a8f51f35467b8d7ba05b","status":"affected","lessThan":"90b744066ca520d1a6a505a11ade9c9a5f48accf","versionType":"git"},{"version":"168e28305b871d8ec604a8f51f35467b8d7ba05b","status":"affected","lessThan":"79993e9919a87068183ba3622c383f05c049c4bc","versionType":"git"},{"version":"168e28305b871d8ec604a8f51f35467b8d7ba05b","status":"affected","lessThan":"555ff78fa719f50ff4cdbdb40aa1acc6e8e327d3","versionType":"git"},{"version":"6.12.6","status":"affected","lessThan":"6.12.113","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/iso.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.11","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/iso.c"]}],"references":["https://git.kernel.org/stable/c/559e4d2b6f83aaa96061659cc7104b7a0293f9ef","https://git.kernel.org/stable/c/90b744066ca520d1a6a505a11ade9c9a5f48accf","https://git.kernel.org/stable/c/79993e9919a87068183ba3622c383f05c049c4bc","https://git.kernel.org/stable/c/555ff78fa719f50ff4cdbdb40aa1acc6e8e327d3"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99013.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99013","state":"PUBLISHED","datePublished":"2026-10-23T12:20:38.612Z","dateUpdated":"2026-10-24T14:10:01.562Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.385Z"},"containers":{"cna":{"title":"Bluetooth: ISO: Reject concurrent BIS listener setup","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: Reject concurrent BIS listener setup\n\niso_sock_listen() drops the socket lock before calling iso_listen_bis()\nto preserve the hdev->lock ordering. Two concurrent listen() calls on\nthe same broadcast socket can therefore both observe BT_BOUND. Caller\nA can attach connA and release the locks, then caller B can acquire\nthem and attach connB before A publishes BT_LISTEN.\n\n__iso_chan_add() checks whether connB already has a socket, but not\nwhether the socket already has a connection. The second attachment\noverwrites iso_pi(sk)->conn, leaking the connA reference and leaving\nconnA->sk intact. Socket teardown follows connB, so later events on\nconnA can cause a stale socket access.\n\nRecheck BT_BOUND and require iso_pi(sk)->conn to be NULL after taking\nboth the HCI device and socket locks in iso_listen_bis(). The connection\ncheck also covers the interval between attachment and publication of\nBT_LISTEN. Reject a competing setup with -EBADFD through the existing\nunlock path before allocating another connection.\n\nA recorded KASAN report from an instrumented kernel shows:\n\n  BUG: KASAN: slab-use-after-free in iso_sock_hold+0x119/0x1f0\n  Call Trace:\n   iso_sock_hold+0x119/0x1f0\n   iso_conn_del+0xe4/0x270\n   hci_disconn_complete_evt+0x351/0x8c0\n   hci_event_packet+0x71b/0xb20\n   hci_rx_work+0x293/0x730\n\n  Allocated by task 93:\n   sk_prot_alloc+0x113/0x220\n   sk_alloc+0x2b/0x6d0\n   bt_sock_alloc+0x29/0x370\n   iso_sock_alloc.constprop.0+0x19/0x300\n   iso_sock_create+0x94/0x100\n\n  Freed by task 93:\n   kfree+0x121/0x3c0\n   __sk_destruct+0x42b/0x540\n   iso_sock_release+0x29d/0x340\n   __sock_release+0xa1/0x260\n   sock_close+0x10/0x20"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c541d7b5e17987ed330798b07d4ad508859c1c93","status":"affected","lessThan":"559e4d2b6f83aaa96061659cc7104b7a0293f9ef","versionType":"git"},{"version":"168e28305b871d8ec604a8f51f35467b8d7ba05b","status":"affected","lessThan":"90b744066ca520d1a6a505a11ade9c9a5f48accf","versionType":"git"},{"version":"168e28305b871d8ec604a8f51f35467b8d7ba05b","status":"affected","lessThan":"79993e9919a87068183ba3622c383f05c049c4bc","versionType":"git"},{"version":"168e28305b871d8ec604a8f51f35467b8d7ba05b","status":"affected","lessThan":"555ff78fa719f50ff4cdbdb40aa1acc6e8e327d3","versionType":"git"},{"version":"6.12.6","status":"affected","lessThan":"6.12.113","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/iso.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.11","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/iso.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/559e4d2b6f83aaa96061659cc7104b7a0293f9ef"},{"url":"https://git.kernel.org/stable/c/90b744066ca520d1a6a505a11ade9c9a5f48accf"},{"url":"https://git.kernel.org/stable/c/79993e9919a87068183ba3622c383f05c049c4bc"},{"url":"https://git.kernel.org/stable/c/555ff78fa719f50ff4cdbdb40aa1acc6e8e327d3"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bad state is created by one process issuing two concurrent listen() syscalls on the same bound BTPROTO_ISO socket; __sys_listen_socket() reaches iso_sock_listen() and the patched iso_listen_bis(). An HCI disconnect only consumes the stranded connA->sk, so an adjacent peer cannot create the race alone.\nAC:L - Attacker threads control both listen() calls and can make each observe BT_BOUND before either publishes BT_LISTEN, causing hci_pa_create_sync() to create separate candidates. The attacker can close the socket and end its own broadcast/sync to drive teardown, without victim-controlled timing.\nPR:L - bt_sock_create(), iso_sock_create(), iso_sock_bind(), and iso_sock_listen() contain no capable() or ns_capable() check, so an ordinary process in init_net can create and race the socket. A separate network namespace is rejected, but no user namespace or capability is needed.\nUI:N - The attacker creates and binds the ISO socket, launches both listen() calls, and closes it; the later HCI callback is asynchronous kernel/controller work. No victim action is required.\nS:U - iso_conn_del() corrupts memory within the same host kernel that implements the attacker's ISO socket; the path crosses no VM, IOMMU, or other security authority boundary.\nC:H - After iso_pi(sk)->conn is overwritten, connA retains connA->sk and iso_sock_hold() can refcount a freed or reclaimed kmalloc-2k struct iso_pinfo. Exploiting the ensuing callback-capable socket operations permits control-flow hijack and arbitrary kernel-memory disclosure.\nI:H - iso_conn_del() passes the stale sk to iso_chan_del(), which writes sk_state and sk_err and invokes sk_state_change or parent->sk_data_ready. Reclaiming the freed object can turn these operations into arbitrary writes or control-flow hijacking.\nA:H - KASAN observed the slab use-after-free in iso_sock_hold() from hci_disconn_complete_evt() after iso_sock_release() freed the socket. Invalid refcount, locking, and callback accesses can cause a kernel oops or panic."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-24T14:10:01.562Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.6","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.2.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}