# CVE-2024-46797: linux: In the Linux kernel, the following vulnerability has been resolved: powerpc/qspinlock: Fix deadlock in MCS queue If... CVE-2024-46797 is fixed in 28 products on 1 platform, first by DEBIAN-CVE-2024-46797, released September 18, 2024. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2024-46797 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0016 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Sep 18, 2024 ## Description In the Linux kernel, the following vulnerability has been resolved: powerpc/qspinlock: Fix deadlock in MCS queue If an interrupt occurs in queued_spin_lock_slowpath() after we increment qnodesp->count and before node->lock is initialized, another CPU might see stale lock values in get_tail_qnode(). If the stale lock value happens to match the lock on that CPU, then we write to the "next" pointer of the wrong qnode. This causes a deadlock as the former CPU, once it becomes the head of the MCS queue, will spin indefinitely until it's "next" pointer is set by its successor in the queue. Running stress-ng on a 16 core (16EC/16VP) shared LPAR, results in occasional lockups similar to the following: $ stress-ng --all 128 --vm-bytes 80% --aggressive \ --maximize --oomable --verify --syslog \ --metrics --times --timeout 5m watchdog: CPU 15 Hard LOCKUP ...... NIP [c0000000000b78f4] queued_spin_lock_slowpath+0x1184/0x1490 LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90 Call Trace: 0xc000002cfffa3bf0 (unreliable) _raw_spin_lock+0x6c/0x90 raw_spin_rq_lock_nested.part.135+0x4c/0xd0 sched_ttwu_pending+0x60/0x1f0 __flush_smp_call_function_queue+0x1dc/0x670 smp_ipi_demux_relaxed+0xa4/0x100 xive_muxed_ipi_action+0x20/0x40 __handle_irq_event_percpu+0x80/0x240 handle_irq_event_percpu+0x2c/0x80 handle_percpu_irq+0x84/0xd0 generic_handle_irq+0x54/0x80 __do_irq+0xac/0x210 __do_IRQ+0x74/0xd0 0x0 do_IRQ+0x8c/0x170 hardware_interrupt_common_virt+0x29c/0x2a0 --- interrupt: 500 at queued_spin_lock_slowpath+0x4b8/0x1490 ...... NIP [c0000000000b6c28] queued_spin_lock_slowpath+0x4b8/0x1490 LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90 --- interrupt: 500 0xc0000029c1a41d00 (unreliable) _raw_spin_lock+0x6c/0x90 futex_wake+0x100/0x260 do_futex+0x21c/0x2a0 sys_futex+0x98/0x270 system_call_exception+0x14c/0x2f0 system_call_vectored_common+0x15c/0x2ec The following code flow illustrates how the deadlock occurs. For the sake of brevity, assume that both locks (A and B) are contended and we call the queued_spin_lock_slowpath() function. CPU0 CPU1 ---- ---- spin_lock_irqsave(A) | spin_unlock_irqrestore(A) | spin_lock(B) | | | ▼ | id = qnodesp->count++; | (Note that nodes[0].lock == A) | | | ▼ | Interrupt | (happens before "nodes[0].lock = B") | | | ▼ | spin_lock_irqsave(A) | | | ▼ | id = qnodesp->count++ | nodes[1].lock = A | | | ▼ | Tail of MCS queue | | spin_lock_irqsave(A) ▼ | Head of MCS queue ▼ | CPU0 is previous tail ▼ | Spin indefinitely ▼ (until "nodes[1].next != NULL") prev = get_tail_qnode(A, CPU0) | ▼ prev == &qnodes[CPU0].nodes[0] (as qnodes ---truncated--- ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | dtb-aarch64 opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-64kb opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-64kb sles 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-azure opensuse-leap 15.6 | 6.4.0-150600.8.17.2 | [SUSE-SU-2024:3984-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3984-1.md) | Nov 13, 2024 | | Linux | kernel-azure sles 15.6 | 6.4.0-150600.8.17.2 | [SUSE-SU-2024:3984-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3984-1.md) | Nov 13, 2024 | | Linux | kernel-coco sles 15.6 | 6.4.0-15061.9.coco15sp6.1 | [SUSE-SU-2024:4387-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4387-1.md) | Dec 19, 2024 | | Linux | kernel-coco_debug sles 15.6 | 6.4.0-15061.9.coco15sp6.1 | [SUSE-SU-2024:4387-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4387-1.md) | Dec 19, 2024 | | Linux | kernel-debug opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-default opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-default sles 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-default-base opensuse-leap 15.6 | 6.4.0-150600.23.30.1.150600.12.12.6 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-default-base sles 15.6 | 6.4.0-150600.23.30.1.150600.12.12.6 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-docs opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-docs sles 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-kvmsmall opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-livepatch-SLE15-SP6-RT_Update_4 sles 15.6 | 1-150600.1.3.1 | [SUSE-SU-2024:3564-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3564-1.md) | Oct 9, 2024 | | Linux | kernel-livepatch-SLE15-SP6-RT_Update_5 sles 15.6 | 1-150600.1.3.1 | [SUSE-SU-2024:3986-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3986-1.md) | Nov 13, 2024 | | Linux | kernel-livepatch-SLE15-SP6_Update_5 sles 15.6 | 1-150600.13.3.1 | [SUSE-SU-2024:3561-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3561-1.md) | Oct 9, 2024 | | Linux | kernel-livepatch-SLE15-SP6_Update_6 sles 15.6 | 1-150600.13.3.5 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-obs-build opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-obs-build sles 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-obs-qa opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-rt opensuse-leap 15.6 | 6.4.0-150600.10.17.1 | [SUSE-SU-2024:3986-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3986-1.md) | Nov 13, 2024 | | Linux | kernel-rt_debug opensuse-leap 15.6 | 6.4.0-150600.10.17.1 | [SUSE-SU-2024:3986-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3986-1.md) | Nov 13, 2024 | | Linux | kernel-source opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-source sles 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-source-azure opensuse-leap 15.6 | 6.4.0-150600.8.17.1 | [SUSE-SU-2024:3984-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3984-1.md) | Nov 13, 2024 | | Linux | kernel-source-azure sles 15.6 | 6.4.0-150600.8.17.1 | [SUSE-SU-2024:3984-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3984-1.md) | Nov 13, 2024 | | Linux | kernel-source-coco sles 15.6 | 6.4.0-15061.9.coco15sp6.1 | [SUSE-SU-2024:4387-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4387-1.md) | Dec 19, 2024 | | Linux | kernel-source-rt opensuse-leap 15.6 | 6.4.0-150600.10.17.1 | [SUSE-SU-2024:3986-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3986-1.md) | Nov 13, 2024 | | Linux | kernel-syms opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-syms sles 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-syms-azure opensuse-leap 15.6 | 6.4.0-150600.8.17.1 | [SUSE-SU-2024:3984-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3984-1.md) | Nov 13, 2024 | | Linux | kernel-syms-azure sles 15.6 | 6.4.0-150600.8.17.1 | [SUSE-SU-2024:3984-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3984-1.md) | Nov 13, 2024 | | Linux | kernel-syms-coco sles 15.6 | 6.4.0-15061.9.coco15sp6.1 | [SUSE-SU-2024:4387-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4387-1.md) | Dec 19, 2024 | | Linux | kernel-syms-rt opensuse-leap 15.6 | 6.4.0-150600.10.17.1 | [SUSE-SU-2024:3986-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-3986-1.md) | Nov 13, 2024 | | Linux | kernel-zfcpdump opensuse-leap 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | kernel-zfcpdump sles 15.6 | 6.4.0-150600.23.30.1 | [SUSE-SU-2024:4318-1](https://patchblox.com/security/data/fix/linux/suse-su-2024-4318-1.md) | Dec 13, 2024 | | Linux | linux Debian 13.5 (trixie) | 6.10.11-1 | [DEBIAN-CVE-2024-46797](https://patchblox.com/security/data/fix/linux/debian-cve-2024-46797.md) | Sep 18, 2024 | | Linux | linux Debian 14 | 6.10.11-1 | [DEBIAN-CVE-2024-46797](https://patchblox.com/security/data/fix/linux/debian-cve-2024-46797.md) | Sep 18, 2024 | --- Data as of 2026-11-08T06:59:42Z UTC. 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