{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74617","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.920Z","datePublished":"2026-08-22T15:32:02.049Z","dateUpdated":"2026-08-25T05:40:44.661Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-25T05:40:44.661Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndibs: initialise dibs->lock in dibs_dev_alloc()\n\ndibs->lock is initialised by dibs_dev_add(), but a dibs device can\nalready take interrupts before that call: ism_probe() runs\nism_dev_init(), and hence request_irq(), before it calls\ndibs_dev_add(). No client can have registered a dmb at that point, so\nno dmb interrupt can occur, but a GID event interrupt can, and\nism_handle_irq() takes dibs->lock unconditionally on entry, before it\ninspects anything else.\n\nInitialise the lock in dibs_dev_alloc() instead, so that it is valid as\nsoon as a driver can publish the device to its interrupt handler."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - On IBM Z SMC-D systems, a remote networked peer on the shared ISM fabric can emit GID/IEQ fabric events that raise ISM MSI interrupts during ism_probe, reaching ism_handle_irq() without any local syscall or ioctl on the victim.\nAC:L - The attacker controls timing by repeatedly sending ISM GID/IEQ fabric events (or coordinating with victim reboot/module reprobe) to hit the probe window between request_irq() and dibs_dev_add(), rather than depending on uncontrollable memory layout.\nPR:N - Exploitation is driven by ISM hardware interrupts from fabric events and does not require local credentials, capabilities, or namespaces on the victim; a remote/co-tenant ISM fabric peer can trigger the IRQ path during device bring-up.\nUI:N - The race occurs automatically during kernel boot or ISM driver probe when fabric GID events arrive; no victim user action such as mounting a filesystem or opening a device node is required.\nS:U - The flaw corrupts kernel driver state via an uninitialized spinlock in IRQ context but does not cross a VM, IOMMU, or sandbox security boundary; impact remains within kernel privilege.\nC:H - Calling spin_lock() on an uninitialized dibs->lock is undefined behavior that can corrupt lock metadata and adjacent dibs_dev fields, creating a memory-safety primitive that can be leveraged for arbitrary kernel memory disclosure.\nI:H - Broken spinlock initialization can permit unsafe concurrent access to dibs_dev state and enable arbitrary kernel memory writes or control-flow hijacking, not merely a clean denial of service.\nA:H - Taking an uninitialized spinlock in ism_handle_irq() can trigger kernel BUG/oops/panic or wedge ISM interrupt handling, causing a high-severity system crash or hang on affected IBM Z hosts."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dibs/dibs_main.c","include/linux/dibs.h"],"versions":[{"version":"cc21191b584c6f7836b0f10774f8278b7cbfba10","lessThan":"fe79571f40434b257d68cbfb7b3ae93a794d8a11","status":"affected","versionType":"git"},{"version":"cc21191b584c6f7836b0f10774f8278b7cbfba10","lessThan":"2926031acba100d0c18fcfaa7a2ed29609318848","status":"affected","versionType":"git"},{"version":"cc21191b584c6f7836b0f10774f8278b7cbfba10","lessThan":"c27e360545373b7aee9862a5beef3b9fb3df0c25","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/dibs/dibs_main.c","include/linux/dibs.h"],"versions":[{"version":"6.18","status":"affected"},{"version":"0","lessThan":"6.18","status":"unaffected","versionType":"semver"},{"version":"6.18.45","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.9","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","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":"6.18","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/fe79571f40434b257d68cbfb7b3ae93a794d8a11"},{"url":"https://git.kernel.org/stable/c/2926031acba100d0c18fcfaa7a2ed29609318848"},{"url":"https://git.kernel.org/stable/c/c27e360545373b7aee9862a5beef3b9fb3df0c25"}],"title":"dibs: initialise dibs->lock in dibs_dev_alloc()","x_generator":{"engine":"bippy-1.2.0"}}}}