{"id":"CVE-2026-53256","state":"PUBLISHED","title":"Bluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind()\n\nrfcomm_get_sock_by_channel() scans rfcomm_sk_list under the list lock,\nbut returns the selected listener after dropping that lock without\ntaking a reference. rfcomm_connect_ind() then locks the listener,\nqueues a child socket on it, and may notify it after unlocking it.\n\nThe buggy scenario involves two paths, with each column showing the\norder within that path:\n\nrfcomm_connect_ind():            listener close:\n  1. Find parent in              1. close() enters\n     rfcomm_get_sock_by_channel()   rfcomm_sock_release().\n  2. Drop rfcomm_sk_list.lock    2. rfcomm_sock_shutdown()\n     without pinning parent.        closes the listener.\n  3. Call lock_sock(parent) and  3. rfcomm_sock_kill()\n     bt_accept_enqueue(parent,      unlinks and puts parent.\n     sk, true).\n  4. Read parent flags and may   4. parent can be freed.\n     call sk_state_change().\n\nIf close wins the race, parent can be freed before\nrfcomm_connect_ind() reaches lock_sock(), bt_accept_enqueue(), or the\ndeferred-setup callback.\n\nTake a reference on the listener before leaving rfcomm_sk_list.lock.\nAfter lock_sock() succeeds, recheck that it is still in BT_LISTEN\nbefore queueing a child, cache the deferred-setup bit while the parent\nis locked, and drop the reference after the last parent use.\n\nKASAN reported a slab-use-after-free in lock_sock_nested() from\nrfcomm_connect_ind(), with the freeing stack going through\nrfcomm_sock_kill() and rfcomm_sock_release().","publishedAt":"2026-06-25T08:39:46.591Z","updatedAt":"2026-10-19T19:57:32.092Z","severity":{"score":8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/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":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f5ec76bdbeb80f75ad0be204371afffee0f8fac8","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"a07d741c077d4e34b16458241a94d29039386553","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"1f73f92f66251065a5f39b09a47cf05ea14d3107","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"de31973ef00e5aa55496f84cf6a44bb157a34e02","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b0e33e409715c617e2a20f46f99aa5403a14dfda","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"8802413ce63175fb522a2bd609fb043a3550c720","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6f4462d12133106460d7c046b95aad2491e3fddf","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"43c441edacf953b39517a44f5e5e10a93618b226","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/rfcomm/sock.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/rfcomm/sock.c"]}],"references":["https://git.kernel.org/stable/c/f5ec76bdbeb80f75ad0be204371afffee0f8fac8","https://git.kernel.org/stable/c/a07d741c077d4e34b16458241a94d29039386553","https://git.kernel.org/stable/c/1f73f92f66251065a5f39b09a47cf05ea14d3107","https://git.kernel.org/stable/c/de31973ef00e5aa55496f84cf6a44bb157a34e02","https://git.kernel.org/stable/c/b0e33e409715c617e2a20f46f99aa5403a14dfda","https://git.kernel.org/stable/c/8802413ce63175fb522a2bd609fb043a3550c720","https://git.kernel.org/stable/c/6f4462d12133106460d7c046b95aad2491e3fddf","https://git.kernel.org/stable/c/43c441edacf953b39517a44f5e5e10a93618b226","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53256.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53256","state":"PUBLISHED","datePublished":"2026-06-25T08:39:46.591Z","dateUpdated":"2026-10-19T19:57:32.092Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.394Z"},"containers":{"cna":{"title":"Bluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: hold listener socket in rfcomm_connect_ind()\n\nrfcomm_get_sock_by_channel() scans rfcomm_sk_list under the list lock,\nbut returns the selected listener after dropping that lock without\ntaking a reference. rfcomm_connect_ind() then locks the listener,\nqueues a child socket on it, and may notify it after unlocking it.\n\nThe buggy scenario involves two paths, with each column showing the\norder within that path:\n\nrfcomm_connect_ind():            listener close:\n  1. Find parent in              1. close() enters\n     rfcomm_get_sock_by_channel()   rfcomm_sock_release().\n  2. Drop rfcomm_sk_list.lock    2. rfcomm_sock_shutdown()\n     without pinning parent.        closes the listener.\n  3. Call lock_sock(parent) and  3. rfcomm_sock_kill()\n     bt_accept_enqueue(parent,      unlinks and puts parent.\n     sk, true).\n  4. Read parent flags and may   4. parent can be freed.\n     call sk_state_change().\n\nIf close wins the race, parent can be freed before\nrfcomm_connect_ind() reaches lock_sock(), bt_accept_enqueue(), or the\ndeferred-setup callback.\n\nTake a reference on the listener before leaving rfcomm_sk_list.lock.\nAfter lock_sock() succeeds, recheck that it is still in BT_LISTEN\nbefore queueing a child, cache the deferred-setup bit while the parent\nis locked, and drop the reference after the last parent use.\n\nKASAN reported a slab-use-after-free in lock_sock_nested() from\nrfcomm_connect_ind(), with the freeing stack going through\nrfcomm_sock_kill() and rfcomm_sock_release()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f5ec76bdbeb80f75ad0be204371afffee0f8fac8","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"a07d741c077d4e34b16458241a94d29039386553","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"1f73f92f66251065a5f39b09a47cf05ea14d3107","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"de31973ef00e5aa55496f84cf6a44bb157a34e02","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"b0e33e409715c617e2a20f46f99aa5403a14dfda","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"8802413ce63175fb522a2bd609fb043a3550c720","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6f4462d12133106460d7c046b95aad2491e3fddf","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"43c441edacf953b39517a44f5e5e10a93618b226","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/rfcomm/sock.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/bluetooth/rfcomm/sock.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f5ec76bdbeb80f75ad0be204371afffee0f8fac8"},{"url":"https://git.kernel.org/stable/c/a07d741c077d4e34b16458241a94d29039386553"},{"url":"https://git.kernel.org/stable/c/1f73f92f66251065a5f39b09a47cf05ea14d3107"},{"url":"https://git.kernel.org/stable/c/de31973ef00e5aa55496f84cf6a44bb157a34e02"},{"url":"https://git.kernel.org/stable/c/b0e33e409715c617e2a20f46f99aa5403a14dfda"},{"url":"https://git.kernel.org/stable/c/8802413ce63175fb522a2bd609fb043a3550c720"},{"url":"https://git.kernel.org/stable/c/6f4462d12133106460d7c046b95aad2491e3fddf"},{"url":"https://git.kernel.org/stable/c/43c441edacf953b39517a44f5e5e10a93618b226"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - The vulnerable path is reached by Bluetooth RFCOMM/L2CAP traffic from a nearby peer, so the attacker must be within Bluetooth radio range rather than merely local or internet-routable.\nAC:L - The race is between an inbound RFCOMM connect indication and listener close; an attacker with an unprivileged local RFCOMM listener plus a controlled adjacent Bluetooth peer can drive both sides repeatedly.\nPR:L - Creating, binding, listening on, and closing an RFCOMM stream socket has no CAP_NET_ADMIN gate, so only low local privileges are needed to control the listener side of the race.\nUI:N - No victim user action is required once the vulnerable listener/race setup exists; the attacker drives the RFCOMM connection attempts and close timing.\nS:U - The corruption is within the kernel networking/Bluetooth socket lifetime domain and does not cross a separate security authority such as a VM or IOMMU boundary.\nC:H - This is a slab use-after-free of a kernel struct sock, and the stale pointer is reused for locking, queueing, state checks, and callback-related state, making high confidentiality impact defensible.\nI:H - The stale listener socket can be operated on after free, including accept-queue manipulation and potential callback use, so kernel memory corruption/control-flow exploitation is defensible.\nA:H - KASAN reported a slab-use-after-free in this path, and even non-exploited triggering can crash or oops the kernel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:34:36.875Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.94"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 TM MFP - GNU/Linux subsystem","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:23:03.918Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-53256","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:27:52.306248Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:57:32.092Z"}}]}}}