{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-72482", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.935Z", "datePublished": "2026-08-15T05:57:20.247Z", "dateUpdated": "2026-08-17T05:44:45.643Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:44:45.643Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngpib: fix double decrement of descriptor_busy in command_ioctl()\n\ncommit d1857f8296dc (\"gpib: fix use-after-free in IO ioctl handlers\")\nintroduced a descriptor_busy reference counter to pin struct\ngpib_descriptor across IO ioctl operations. In command_ioctl(), the\nerror path inside the loop decrements descriptor_busy and breaks, but\nexecution then falls through to the unconditional decrement after the\nloop, underflowing the counter to -1.\n\nThis re-enables the use-after-free that the original fix was meant to\nprevent: a concurrent close_dev_ioctl() sees descriptor_busy == 0 on\nan actively-used descriptor and frees it.\n\nRemove the early decrement from the error path. The post-loop\ndecrement already handles all exit paths, matching the correct pattern\nused in read_ioctl() and write_ioctl()." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The bug is reached only through local ioctl on /dev/gpibN character devices; exploitation requires concurrent IBCMD (command_ioctl) and IBCLOSEDEV calls, not remote network traffic or physical GPIB bus manipulation.\nAC:L - Once a GPIB board is online and accessible, an attacker controls both race participants by running a failing IBCMD ioctl in one thread and IBCLOSEDEV on the same handle in another; ibcmd errors (e.g., timeout or missing CIC) are reliably triggerable.\nPR:L - The vulnerable IBCMD and IBCLOSEDEV ioctls perform no capability checks; any local user with access to an already-configured, online GPIB device node can open handles and race command/close operations typical of lab and factory test automation accounts.\nUI:N - No victim interaction is required beyond the attacker already having local access to the GPIB device; exploitation is performed entirely through attacker-controlled ioctl sequences without needing another user to mount, open, or approve actions.\nS:U - This is a kernel heap use-after-free within the GPIB driver reachable from local process ioctls and affects the same kernel security authority; it does not cross virtualization, IOMMU, or separate security-scope boundaries.\nC:H - The erroneous early descriptor_busy decrement lets close_dev_ioctl kfree() the struct while command_ioctl still holds and dereferences it; freed kmalloc slab reuse can expose or help derive kernel memory contents per UAF scoring guidance.\nI:H - Post-free atomic writes to io_in_progress and descriptor_busy on the stale pointer can corrupt attacker-influenced reused heap objects, providing a plausible path to kernel data corruption, write primitives, or privilege escalation.\nA:H - Dereferencing the freed gpib_descriptor during IBCMD completion (atomic_set, atomic_dec, wake_up) can cause kernel oops, BUG, or panic; use-after-free bugs are scored as high availability impact even before full exploitation." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/gpib/common/gpib_os.c" ], "versions": [ { "version": "cae26eff1b56d78bed7873cf3e60a2b1bdd4da6c", "lessThan": "fdee9f207a48ce204ec6cfceaa1459d2473600a5", "status": "affected", "versionType": "git" }, { "version": "d1857f8296dceb75d00ab857fc3c61bc00c7f5c6", "lessThan": "8b5f1d295dda8677e4545ce340053fcfa8b634c7", "status": "affected", "versionType": "git" }, { "version": "d1857f8296dceb75d00ab857fc3c61bc00c7f5c6", "lessThan": "c4faab452b3c1ada003d49c477609dd80523b9bf", "status": "affected", "versionType": "git" }, { "version": "28c75dd143ead62e0dfac564c79d251e21d5d74b", "status": "affected", "versionType": "git" }, { "version": "6.18.22", "lessThan": "6.18.40", "status": "affected", "versionType": "semver" }, { "version": "6.19.12", "lessThan": "6.20", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/gpib/common/gpib_os.c" ], "versions": [ { "version": "7.0", "status": "affected" }, { "version": "0", "lessThan": "7.0", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.5", "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": "6.18.22", "versionEndExcluding": "6.18.40" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.1.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0", "versionEndExcluding": "7.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/fdee9f207a48ce204ec6cfceaa1459d2473600a5" }, { "url": "https://git.kernel.org/stable/c/8b5f1d295dda8677e4545ce340053fcfa8b634c7" }, { "url": "https://git.kernel.org/stable/c/c4faab452b3c1ada003d49c477609dd80523b9bf" } ], "title": "gpib: fix double decrement of descriptor_busy in command_ioctl()", "x_generator": { "engine": "bippy-1.2.0" } } } }