{"api_version":"1","generated_at":"2026-08-22T04:10:54+00:00","cve":"CVE-2026-72342","urls":{"html":"https://cve.report/CVE-2026-72342","api":"https://cve.report/api/cve/CVE-2026-72342.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-72342","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72342"},"summary":{"title":"net/mlx5e: Fix HV VHCA stats agent registration race","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix HV VHCA stats agent registration race\n\nmlx5e_hv_vhca_stats_create() registers the stats agent through\nmlx5_hv_vhca_agent_create(). The helper publishes the agent in\nhv_vhca->agents[type] under agents_lock and immediately schedules an\nasynchronous control invalidation on the HV VHCA workqueue before\nreturning to mlx5e.\n\nThe asynchronous invalidation invokes the control agent's invalidate\ncallback, which reads the hypervisor control block and forwards the\ncommand to mlx5e_hv_vhca_stats_control(). That callback may either:\n\n  - call cancel_delayed_work_sync(&priv->stats_agent.work), or\n  - call queue_delayed_work(priv->wq, &sagent->work, sagent->delay).\n\nHowever, the delayed_work and priv->stats_agent.agent are only\ninitialized after mlx5_hv_vhca_agent_create() returns to mlx5e:\n\n    agent = mlx5_hv_vhca_agent_create(...);   /* publish + invalidate */\n    ...\n    priv->stats_agent.agent = agent;          /* too late */\n    INIT_DELAYED_WORK(&priv->stats_agent.work, ...); /* too late */\n\nIf the asynchronous control path runs before the two assignments\nabove, it can:\n\n  - Operate on an uninitialized delayed_work whose timer.function is\n    NULL. queue_delayed_work() calls add_timer() unconditionally, so\n    when the timer expires the timer softirq invokes a NULL function\n    pointer.\n  - Re-initialize the timer later through INIT_DELAYED_WORK() while\n    the timer is already enqueued in the timer wheel, corrupting the\n    hlist (entry.pprev cleared while the previous bucket node still\n    points at this entry).\n  - When the worker eventually runs, mlx5e_hv_vhca_stats_work() reads\n    sagent->agent (NULL) and dereferences it inside\n    mlx5_hv_vhca_agent_write().\n\nFix this by:\n\n  - Initializing priv->stats_agent.work before invoking\n    mlx5_hv_vhca_agent_create(), so the work is always in a valid\n    state when the control callback observes it.\n  - Adding a struct mlx5_hv_vhca_agent **ctx_update out-parameter\n    to mlx5_hv_vhca_agent_create(). The helper writes the agent\n    pointer to *ctx_update before publishing into hv_vhca->agents[]\n    and triggering the agents_update flow, so any callback\n    subsequently invoked from that flow already sees a valid\n    priv->stats_agent.agent. This avoids having the control\n    callback participate in agent initialization.\n\nWhile at it, access priv->stats_agent.agent with\nREAD_ONCE()/WRITE_ONCE() for the cross-CPU access with the worker, and\nclear priv->stats_agent.buf on the agent_create() failure path.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:22:07","updated_at":"2026-08-17 06:18:38"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"8.4","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"8.4","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":8.4,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/e8fc3304cb67fb1d7d11ff9ef9abd5fb64e7e1d5","name":"https://git.kernel.org/stable/c/e8fc3304cb67fb1d7d11ff9ef9abd5fb64e7e1d5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f5677797b094c3ec5fb350eb8ea7710b88a3d018","name":"https://git.kernel.org/stable/c/f5677797b094c3ec5fb350eb8ea7710b88a3d018","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/89b25b5f46f488ea3b29b3444864c76944c9075b","name":"https://git.kernel.org/stable/c/89b25b5f46f488ea3b29b3444864c76944c9075b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/24c77044cdfcf5b8b2e9f3b620d8b9aa392d9add","name":"https://git.kernel.org/stable/c/24c77044cdfcf5b8b2e9f3b620d8b9aa392d9add","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b0fd6d3bb06182f19f3b59a53f57b5098b99048a","name":"https://git.kernel.org/stable/c/b0fd6d3bb06182f19f3b59a53f57b5098b99048a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/60fddda7207d81fea71463abd403f0b10f74f2e1","name":"https://git.kernel.org/stable/c/60fddda7207d81fea71463abd403f0b10f74f2e1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72342","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72342","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cef35af34d6dc3792333075115c7deb7062b6e18 b0fd6d3bb06182f19f3b59a53f57b5098b99048a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cef35af34d6dc3792333075115c7deb7062b6e18 24c77044cdfcf5b8b2e9f3b620d8b9aa392d9add git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cef35af34d6dc3792333075115c7deb7062b6e18 e8fc3304cb67fb1d7d11ff9ef9abd5fb64e7e1d5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cef35af34d6dc3792333075115c7deb7062b6e18 60fddda7207d81fea71463abd403f0b10f74f2e1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cef35af34d6dc3792333075115c7deb7062b6e18 f5677797b094c3ec5fb350eb8ea7710b88a3d018 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cef35af34d6dc3792333075115c7deb7062b6e18 89b25b5f46f488ea3b29b3444864c76944c9075b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.4","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.4 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"72342","cve":"CVE-2026-72342","epss":"0.001930000","percentile":"0.093310000","score_date":"2026-08-17","updated_at":"2026-08-18 00:11:47"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c","drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.c","drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"b0fd6d3bb06182f19f3b59a53f57b5098b99048a","status":"affected","version":"cef35af34d6dc3792333075115c7deb7062b6e18","versionType":"git"},{"lessThan":"24c77044cdfcf5b8b2e9f3b620d8b9aa392d9add","status":"affected","version":"cef35af34d6dc3792333075115c7deb7062b6e18","versionType":"git"},{"lessThan":"e8fc3304cb67fb1d7d11ff9ef9abd5fb64e7e1d5","status":"affected","version":"cef35af34d6dc3792333075115c7deb7062b6e18","versionType":"git"},{"lessThan":"60fddda7207d81fea71463abd403f0b10f74f2e1","status":"affected","version":"cef35af34d6dc3792333075115c7deb7062b6e18","versionType":"git"},{"lessThan":"f5677797b094c3ec5fb350eb8ea7710b88a3d018","status":"affected","version":"cef35af34d6dc3792333075115c7deb7062b6e18","versionType":"git"},{"lessThan":"89b25b5f46f488ea3b29b3444864c76944c9075b","status":"affected","version":"cef35af34d6dc3792333075115c7deb7062b6e18","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c","drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.c","drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.h"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.4"},{"lessThan":"5.4","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"5.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"5.4","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix HV VHCA stats agent registration race\n\nmlx5e_hv_vhca_stats_create() registers the stats agent through\nmlx5_hv_vhca_agent_create(). The helper publishes the agent in\nhv_vhca->agents[type] under agents_lock and immediately schedules an\nasynchronous control invalidation on the HV VHCA workqueue before\nreturning to mlx5e.\n\nThe asynchronous invalidation invokes the control agent's invalidate\ncallback, which reads the hypervisor control block and forwards the\ncommand to mlx5e_hv_vhca_stats_control(). That callback may either:\n\n  - call cancel_delayed_work_sync(&priv->stats_agent.work), or\n  - call queue_delayed_work(priv->wq, &sagent->work, sagent->delay).\n\nHowever, the delayed_work and priv->stats_agent.agent are only\ninitialized after mlx5_hv_vhca_agent_create() returns to mlx5e:\n\n    agent = mlx5_hv_vhca_agent_create(...);   /* publish + invalidate */\n    ...\n    priv->stats_agent.agent = agent;          /* too late */\n    INIT_DELAYED_WORK(&priv->stats_agent.work, ...); /* too late */\n\nIf the asynchronous control path runs before the two assignments\nabove, it can:\n\n  - Operate on an uninitialized delayed_work whose timer.function is\n    NULL. queue_delayed_work() calls add_timer() unconditionally, so\n    when the timer expires the timer softirq invokes a NULL function\n    pointer.\n  - Re-initialize the timer later through INIT_DELAYED_WORK() while\n    the timer is already enqueued in the timer wheel, corrupting the\n    hlist (entry.pprev cleared while the previous bucket node still\n    points at this entry).\n  - When the worker eventually runs, mlx5e_hv_vhca_stats_work() reads\n    sagent->agent (NULL) and dereferences it inside\n    mlx5_hv_vhca_agent_write().\n\nFix this by:\n\n  - Initializing priv->stats_agent.work before invoking\n    mlx5_hv_vhca_agent_create(), so the work is always in a valid\n    state when the control callback observes it.\n  - Adding a struct mlx5_hv_vhca_agent **ctx_update out-parameter\n    to mlx5_hv_vhca_agent_create(). The helper writes the agent\n    pointer to *ctx_update before publishing into hv_vhca->agents[]\n    and triggering the agents_update flow, so any callback\n    subsequently invoked from that flow already sees a valid\n    priv->stats_agent.agent. This avoids having the control\n    callback participate in agent initialization.\n\nWhile at it, access priv->stats_agent.agent with\nREAD_ONCE()/WRITE_ONCE() for the cross-CPU access with the worker, and\nclear priv->stats_agent.buf on the agent_create() failure path."}],"metrics":[{"cvssV3_1":{"baseScore":8.4,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The bug is in mlx5e HV VHCA stats agent registration during mlx5e driver attach on Hyper-V/Azure mlx5 NICs; it is reached via the VMBus PCI config back-channel and driver init, not via remote network packet handling.\nAC:L - mlx5_hv_vhca_agent_create() always queues asynchronous control invalidation before returning; on SMP hosts the workqueue races unfinished delayed_work/agent setup, and the path can be re-triggered via devlink reload or driver reattach.\nPR:N - No guest privileges are required: the race opens during normal mlx5e attach at boot/resume on CONFIG_PCI_HYPERV_INTERFACE systems, and the hypervisor can drive the control callback via the VHCA control block without guest credentials.\nUI:N - No user or administrator action is needed beyond normal VM boot and mlx5 driver initialization; exploitation does not depend on a victim opening files, mounting filesystems, or other interactive steps.\nS:U - Memory corruption and kernel crashes are confined to the guest kernel running mlx5e; the bug does not cross VM/host, IOMMU, or other security boundaries into a separate authority.\nC:H - The race can corrupt the kernel timer wheel hlist, invoke a NULL timer callback, or dereference a NULL agent during mlx5_hv_vhca_agent_write(), providing serious kernel memory corruption or disclosure primitives.\nI:H - Timer wheel hlist corruption and operating on uninitialized delayed_work structures are exploitable memory corruption that can be leveraged for arbitrary kernel writes or control-flow hijacking, not merely a bounded fault.\nA:H - Exploitation causes kernel oops/panic from NULL function-pointer timer callbacks, corrupted timer lists, or NULL agent dereferences, reliably denying availability of the affected system."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:43:00.745Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/b0fd6d3bb06182f19f3b59a53f57b5098b99048a"},{"url":"https://git.kernel.org/stable/c/24c77044cdfcf5b8b2e9f3b620d8b9aa392d9add"},{"url":"https://git.kernel.org/stable/c/e8fc3304cb67fb1d7d11ff9ef9abd5fb64e7e1d5"},{"url":"https://git.kernel.org/stable/c/60fddda7207d81fea71463abd403f0b10f74f2e1"},{"url":"https://git.kernel.org/stable/c/f5677797b094c3ec5fb350eb8ea7710b88a3d018"},{"url":"https://git.kernel.org/stable/c/89b25b5f46f488ea3b29b3444864c76944c9075b"}],"title":"net/mlx5e: Fix HV VHCA stats agent registration race","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-72342","datePublished":"2026-08-15T05:55:48.412Z","dateReserved":"2026-08-09T03:40:39.920Z","dateUpdated":"2026-08-17T05:43:00.745Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:22:07","lastModifiedDate":"2026-08-17 06:18:38","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.4,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":2.5,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"72342","Ordinal":"1","Title":"net/mlx5e: Fix HV VHCA stats agent registration race","CVE":"CVE-2026-72342","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"72342","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix HV VHCA stats agent registration race\n\nmlx5e_hv_vhca_stats_create() registers the stats agent through\nmlx5_hv_vhca_agent_create(). The helper publishes the agent in\nhv_vhca->agents[type] under agents_lock and immediately schedules an\nasynchronous control invalidation on the HV VHCA workqueue before\nreturning to mlx5e.\n\nThe asynchronous invalidation invokes the control agent's invalidate\ncallback, which reads the hypervisor control block and forwards the\ncommand to mlx5e_hv_vhca_stats_control(). That callback may either:\n\n  - call cancel_delayed_work_sync(&priv->stats_agent.work), or\n  - call queue_delayed_work(priv->wq, &sagent->work, sagent->delay).\n\nHowever, the delayed_work and priv->stats_agent.agent are only\ninitialized after mlx5_hv_vhca_agent_create() returns to mlx5e:\n\n    agent = mlx5_hv_vhca_agent_create(...);   /* publish + invalidate */\n    ...\n    priv->stats_agent.agent = agent;          /* too late */\n    INIT_DELAYED_WORK(&priv->stats_agent.work, ...); /* too late */\n\nIf the asynchronous control path runs before the two assignments\nabove, it can:\n\n  - Operate on an uninitialized delayed_work whose timer.function is\n    NULL. queue_delayed_work() calls add_timer() unconditionally, so\n    when the timer expires the timer softirq invokes a NULL function\n    pointer.\n  - Re-initialize the timer later through INIT_DELAYED_WORK() while\n    the timer is already enqueued in the timer wheel, corrupting the\n    hlist (entry.pprev cleared while the previous bucket node still\n    points at this entry).\n  - When the worker eventually runs, mlx5e_hv_vhca_stats_work() reads\n    sagent->agent (NULL) and dereferences it inside\n    mlx5_hv_vhca_agent_write().\n\nFix this by:\n\n  - Initializing priv->stats_agent.work before invoking\n    mlx5_hv_vhca_agent_create(), so the work is always in a valid\n    state when the control callback observes it.\n  - Adding a struct mlx5_hv_vhca_agent **ctx_update out-parameter\n    to mlx5_hv_vhca_agent_create(). The helper writes the agent\n    pointer to *ctx_update before publishing into hv_vhca->agents[]\n    and triggering the agents_update flow, so any callback\n    subsequently invoked from that flow already sees a valid\n    priv->stats_agent.agent. This avoids having the control\n    callback participate in agent initialization.\n\nWhile at it, access priv->stats_agent.agent with\nREAD_ONCE()/WRITE_ONCE() for the cross-CPU access with the worker, and\nclear priv->stats_agent.buf on the agent_create() failure path.","Type":"Description","Title":"net/mlx5e: Fix HV VHCA stats agent registration race"}]}}}