CVE-2026-43385

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-43385", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.006Z", "datePublished": "2026-05-08T14:21:32.007Z", "dateUpdated": "2026-08-05T12:27:43.989Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:27:43.989Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: Fix rcu_tasks stall in threaded busypoll\n\nI was debugging a NIC driver when I noticed that when I enable\nthreaded busypoll, bpftrace hangs when starting up. dmesg showed:\n\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 10658 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 40793 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 131273 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 402058 jiffies old.\n INFO: rcu_tasks detected stalls on tasks:\n 00000000769f52cd: .N nvcsw: 2/2 holdout: 1 idle_cpu: -1/64\n task:napi/eth2-8265 state:R running task stack:0 pid:48300 tgid:48300 ppid:2 task_flags:0x208040 flags:0x00004000\n Call Trace:\n <TASK>\n ? napi_threaded_poll_loop+0x27c/0x2c0\n ? __pfx_napi_threaded_poll+0x10/0x10\n ? napi_threaded_poll+0x26/0x80\n ? kthread+0xfa/0x240\n ? __pfx_kthread+0x10/0x10\n ? ret_from_fork+0x31/0x50\n ? __pfx_kthread+0x10/0x10\n ? ret_from_fork_asm+0x1a/0x30\n </TASK>\n\nThe cause is that in threaded busypoll, the main loop is in\nnapi_threaded_poll rather than napi_threaded_poll_loop, where the\nlatter rarely iterates more than once within its loop. For\nrcu_softirq_qs_periodic inside napi_threaded_poll_loop to report its\nqs state, the last_qs must be 100ms behind, and this can't happen\nbecause napi_threaded_poll_loop rarely iterates in threaded busypoll,\nand each time napi_threaded_poll_loop is called last_qs is reset to\nlatest jiffies.\n\nThis patch changes so that in threaded busypoll, last_qs is saved\nin the outer napi_threaded_poll, and whether busy_poll_last_qs\nis NULL indicates whether napi_threaded_poll_loop is called for\nbusypoll. This way last_qs would not reset to latest jiffies on\neach invocation of napi_threaded_poll_loop."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:N - In a reasonable high-impact deployment, threaded NAPI busy-poll is enabled on a network-facing NIC/forwarder, and received packets schedule the NAPI kthread into the vulnerable polling loop. The netlink knob is an administrative deployment gate, but a remote sender needs no local access once that mode is in use.\nAC:L - There is no attacker-controlled race or fragile timing requirement; once the NAPI thread is in threaded busy-poll mode, repeated loop invocations reliably fail to report RCU Tasks quiescent states. Packet delivery to the configured NAPI is sufficient to activate the path.\nPR:N - The highest-impact scenario is an already-configured network service/device where the attacker only sends packets and needs no account or credentials. Enabling threaded busy-poll itself requires init-namespace CAP_NET_ADMIN, but that is a deployment precondition rather than an exploit privilege in this scenario.\nUI:N - No victim user action is required after the affected NAPI mode is configured. Network traffic alone can keep the vulnerable kthread path active.\nS:U - The impact remains within the kernel and host networking/RCU scheduling authority. There is no VM escape, sandbox boundary crossing, or separate security authority affected.\nC:N - The bug is an RCU Tasks quiescent-state starvation/stall, not memory corruption or an information disclosure path. I found no read primitive or exposure of protected data.\nI:N - The flaw does not provide an arbitrary write, control-flow hijack, or data modification primitive. It only prevents timely RCU Tasks grace-period progress.\nA:H - The vulnerable loop can indefinitely stall RCU Tasks grace periods, causing kernel operations such as tracing/BPF setup or teardown to hang and producing persistent RCU stall reports. This is a kernel-level hang/deadlock-style availability failure."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/core/dev.c"], "versions": [{"version": "c18d4b190a46651726c9a952667c74d2deb33c28", "lessThan": "52459201d0df3fdbb1d281738b7b772e2cacb49c", "status": "affected", "versionType": "git"}, {"version": "c18d4b190a46651726c9a952667c74d2deb33c28", "lessThan": "1a86a1f7d88996085934139fa4c063b6299a2dd3", "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/core/dev.c"], "versions": [{"version": "6.19", "status": "affected"}, {"version": "0", "lessThan": "6.19", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.9", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "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": "6.19", "versionEndExcluding": "6.19.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "7.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/52459201d0df3fdbb1d281738b7b772e2cacb49c"}, {"url": "https://git.kernel.org/stable/c/1a86a1f7d88996085934139fa4c063b6299a2dd3"}], "title": "net: Fix rcu_tasks stall in threaded busypoll", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/core/dev.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "52459201d0df3fdbb1d281738b7b772e2cacb49c", "status": "affected", "version": "c18d4b190a46651726c9a952667c74d2deb33c28", "versionType": "git"}, {"lessThan": "1a86a1f7d88996085934139fa4c063b6299a2dd3", "status": "affected", "version": "c18d4b190a46651726c9a952667c74d2deb33c28", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/core/dev.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.19"}, {"lessThan": "6.19", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.19.*", "status": "unaffected", "version": "6.19.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9", "versionEndExcluding": "6.19.9", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: Fix rcu_tasks stall in threaded busypoll\n\nI was debugging a NIC driver when I noticed that when I enable\nthreaded busypoll, bpftrace hangs when starting up. dmesg showed:\n\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 10658 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 40793 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 131273 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 402058 jiffies old.\n INFO: rcu_tasks detected stalls on tasks:\n 00000000769f52cd: .N nvcsw: 2/2 holdout: 1 idle_cpu: -1/64\n task:napi/eth2-8265 state:R running task stack:0 pid:48300 tgid:48300 ppid:2 task_flags:0x208040 flags:0x00004000\n Call Trace:\n <TASK>\n ? napi_threaded_poll_loop+0x27c/0x2c0\n ? __pfx_napi_threaded_poll+0x10/0x10\n ? napi_threaded_poll+0x26/0x80\n ? kthread+0xfa/0x240\n ? __pfx_kthread+0x10/0x10\n ? ret_from_fork+0x31/0x50\n ? __pfx_kthread+0x10/0x10\n ? ret_from_fork_asm+0x1a/0x30\n </TASK>\n\nThe cause is that in threaded busypoll, the main loop is in\nnapi_threaded_poll rather than napi_threaded_poll_loop, where the\nlatter rarely iterates more than once within its loop. For\nrcu_softirq_qs_periodic inside napi_threaded_poll_loop to report its\nqs state, the last_qs must be 100ms behind, and this can't happen\nbecause napi_threaded_poll_loop rarely iterates in threaded busypoll,\nand each time napi_threaded_poll_loop is called last_qs is reset to\nlatest jiffies.\n\nThis patch changes so that in threaded busypoll, last_qs is saved\nin the outer napi_threaded_poll, and whether busy_poll_last_qs\nis NULL indicates whether napi_threaded_poll_loop is called for\nbusypoll. This way last_qs would not reset to latest jiffies on\neach invocation of napi_threaded_poll_loop."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet: Solucionar el bloqueo de rcu_tasks en busypoll con hilos\n\nEstaba depurando un controlador de NIC cuando not\u00e9 que al habilitar\nbusypoll con hilos, bpftrace se cuelga al iniciar. dmesg mostr\u00f3:\n\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 10658 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 40793 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 131273 jiffies old.\n rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 402058 jiffies old.\n INFO: rcu_tasks detected stalls on tasks:\n 00000000769f52cd: .N nvcsw: 2/2 holdout: 1 idle_cpu: -1/64\n task:napi/eth2-8265 state:R running task stack:0 pid:48300 tgid:48300 ppid:2 task_flags:0x 208040 flags:0x 00004000\n Call Trace:\n [TASK]\n ? napi_threaded_poll_loop+0x27c/0x2c0\n ? __pfx_napi_threaded_poll+0x10/0x10\n ? napi_threaded_poll+0x26/0x80\n ? kthread+0xfa/0x240\n ? __pfx_kthread+0x10/0x10\n ? ret_from_fork+0x31/0x50\n ? __pfx_kthread+0x10/0x10\n ? ret_from_fork_asm+0x1a/0x30\n [/TASK]\n\nLa causa es que en busypoll con hilos, el bucle principal est\u00e1 en\nnapi_threaded_poll en lugar de napi_threaded_poll_loop, donde este\n\u00faltimo rara vez itera m\u00e1s de una vez dentro de su bucle. Para que\nrcu_softirq_qs_periodic dentro de napi_threaded_poll_loop informe su\nestado qs, el last_qs debe estar 100ms atrasado, y esto no puede suceder\nporque napi_threaded_poll_loop rara vez itera en busypoll con hilos,\ny cada vez que se llama a napi_threaded_poll_loop, last_qs se restablece\na los jiffies m\u00e1s recientes.\n\nEste parche cambia para que en busypoll con hilos, last_qs se guarde\nen el napi_threaded_poll externo, y si busy_poll_last_qs es NULL\nindica si napi_threaded_poll_loop es llamado para busypoll. De esta\nmanera, last_qs no se restablecer\u00eda a los jiffies m\u00e1s recientes en\ncada invocaci\u00f3n de napi_threaded_poll_loop."}], "id": "CVE-2026-43385", "lastModified": "2026-11-11T20:10:00.273", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-05-08T15:16:49.830", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/1a86a1f7d88996085934139fa4c063b6299a2dd3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/52459201d0df3fdbb1d281738b7b772e2cacb49c"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: net: Fix rcu_tasks stall in threaded busypoll", "id": "2468191", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2468191"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-821", "details": ["A flaw was found in the Linux kernel where a race condition in the `rcu_tasks` grace period handling within the `napi_threaded_poll_loop` function can lead to a stall. This issue occurs when threaded busypoll is enabled and specific network operations are performed. A local user or a specific workload could exploit this to cause the system to become unresponsive or hang, resulting in a Denial of Service (DoS)."], "name": "CVE-2026-43385", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-05-08T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-43385\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-43385\nhttps://lore.kernel.org/linux-cve-announce/2026050834-CVE-2026-43385-057b@gregkh/T"], "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c18d4b190a46651726c9a952667c74d2deb33c28,52459201d0df3fdbb1d281738b7b772e2cacb49c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[c18d4b190a46651726c9a952667c74d2deb33c28,1a86a1f7d88996085934139fa4c063b6299a2dd3)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "6.19"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.19)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.19.9,6.20.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-05-08T18:30:06.352840+00:00", "updated": "2026-05-26T19:15:13.720733+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}