{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2024-46797", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2024-46797", "idYear": 2024, "status": "PUBLISHED", "publishedAt": "2024-09-18T07:12:51.795Z", "updatedAt": "2026-05-11T20:36:43.772Z", "importedAt": "2026-10-24T01:57:16.009Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "powerpc/qspinlock: Fix deadlock in MCS queue", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/qspinlock: Fix deadlock in MCS queue\n\nIf an interrupt occurs in queued_spin_lock_slowpath() after we increment\nqnodesp->count and before node->lock is initialized, another CPU might\nsee stale lock values in get_tail_qnode(). If the stale lock value happens\nto match the lock on that CPU, then we write to the \"next\" pointer of\nthe wrong qnode. This causes a deadlock as the former CPU, once it becomes\nthe head of the MCS queue, will spin indefinitely until it's \"next\" pointer\nis set by its successor in the queue.\n\nRunning stress-ng on a 16 core (16EC/16VP) shared LPAR, results in\noccasional lockups similar to the following:\n\n $ stress-ng --all 128 --vm-bytes 80% --aggressive \\\n --maximize --oomable --verify --syslog \\\n --metrics --times --timeout 5m\n\n watchdog: CPU 15 Hard LOCKUP\n ......\n NIP [c0000000000b78f4] queued_spin_lock_slowpath+0x1184/0x1490\n LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90\n Call Trace:\n 0xc000002cfffa3bf0 (unreliable)\n _raw_spin_lock+0x6c/0x90\n raw_spin_rq_lock_nested.part.135+0x4c/0xd0\n sched_ttwu_pending+0x60/0x1f0\n __flush_smp_call_function_queue+0x1dc/0x670\n smp_ipi_demux_relaxed+0xa4/0x100\n xive_muxed_ipi_action+0x20/0x40\n __handle_irq_event_percpu+0x80/0x240\n handle_irq_event_percpu+0x2c/0x80\n handle_percpu_irq+0x84/0xd0\n generic_handle_irq+0x54/0x80\n __do_irq+0xac/0x210\n __do_IRQ+0x74/0xd0\n 0x0\n do_IRQ+0x8c/0x170\n hardware_interrupt_common_virt+0x29c/0x2a0\n --- interrupt: 500 at queued_spin_lock_slowpath+0x4b8/0x1490\n ......\n NIP [c0000000000b6c28] queued_spin_lock_slowpath+0x4b8/0x1490\n LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90\n --- interrupt: 500\n 0xc0000029c1a41d00 (unreliable)\n _raw_spin_lock+0x6c/0x90\n futex_wake+0x100/0x260\n do_futex+0x21c/0x2a0\n sys_futex+0x98/0x270\n system_call_exception+0x14c/0x2f0\n system_call_vectored_common+0x15c/0x2ec\n\nThe following code flow illustrates how the deadlock occurs.\nFor the sake of brevity, assume that both locks (A and B) are\ncontended and we call the queued_spin_lock_slowpath() function.\n\n CPU0 CPU1\n ---- ----\n spin_lock_irqsave(A) |\n spin_unlock_irqrestore(A) |\n spin_lock(B) |\n | |\n ▼ |\n id = qnodesp->count++; |\n (Note that nodes[0].lock == A) |\n | |\n ▼ |\n Interrupt |\n (happens before \"nodes[0].lock = B\") |\n | |\n ▼ |\n spin_lock_irqsave(A) |\n | |\n ▼ |\n id = qnodesp->count++ |\n nodes[1].lock = A |\n | |\n ▼ |\n Tail of MCS queue |\n | spin_lock_irqsave(A)\n ▼ |\n Head of MCS queue ▼\n | CPU0 is previous tail\n ▼ |\n Spin indefinitely ▼\n (until \"nodes[1].next != NULL\") prev = get_tail_qnode(A, CPU0)\n |\n ▼\n prev == &qnodes[CPU0].nodes[0]\n (as qnodes\n---truncated---", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "84990b169557428c318df87b7836cd15f65b62dc", "status": "affected", "versionType": "git", "lessThan": "d84ab6661e8d09092de9b034b016515ef9b66085" }, { "version": "84990b169557428c318df87b7836cd15f65b62dc", "status": "affected", "versionType": "git", "lessThan": "f06af737e4be28c0e926dc25d5f0a111da4e2987" }, { "version": "84990b169557428c318df87b7836cd15f65b62dc", "status": "affected", "versionType": "git", "lessThan": "734ad0af3609464f8f93e00b6c0de1e112f44559" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "6.2", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "6.2" }, { "version": "6.6.51", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.10.10", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.10.*" }, { "version": "6.11", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }