{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-39495", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-06-25T14:23:23.751Z", "datePublished": "2024-07-12T12:20:31.022Z", "dateUpdated": "2026-08-05T11:33:44.931Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:33:44.931Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngreybus: Fix use-after-free bug in gb_interface_release due to race condition.\n\nIn gb_interface_create, &intf->mode_switch_completion is bound with\ngb_interface_mode_switch_work. Then it will be started by\ngb_interface_request_mode_switch. Here is the relevant code.\nif (!queue_work(system_long_wq, &intf->mode_switch_work)) {\n\t...\n}\n\nIf we call gb_interface_release to make cleanup, there may be an\nunfinished work. This function will call kfree to free the object\n\"intf\". However, if gb_interface_mode_switch_work is scheduled to\nrun after kfree, it may cause use-after-free error as\ngb_interface_mode_switch_work will use the object \"intf\".\nThe possible execution flow that may lead to the issue is as follows:\n\nCPU0 CPU1\n\n | gb_interface_create\n | gb_interface_request_mode_switch\ngb_interface_release |\nkfree(intf) (free) |\n | gb_interface_mode_switch_work\n | mutex_lock(&intf->mutex) (use)\n\nFix it by canceling the work before kfree." } ], "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 attacker-controlled side of the race is the FW_MGMT_IOC_MODE_SWITCH ioctl on the /dev/gb-fw-mgmt-N character device (drivers/staging/greybus/fw-management.c:503), the sole caller of gb_interface_request_mode_switch(). Greybus is a local bus (USB/UART/serdev transport), not remotely reachable, so exploitation requires local access to the system.\nAC:L - The attacker directly controls the work-queueing side via the ioctl and can retry it in a tight loop indefinitely, while the free side (interface refcount drop via module removal / SVC teardown) can be induced repeatedly by hot-unplug or the 2-second mode-switch timeout path that calls gb_interface_deactivate(). Heap grooming of the ~1KB gb_interface allocation is standard, so the attacker creates and wins the race himself rather than depending on conditions outside his control.\nPR:L - fw_mgmt_ioctl() and fw_mgmt_ioctl_unlocked() contain no capable() or CAP_* check at all; the only gate is the permission on the /dev/gb-fw-mgmt-N node, which on greybus-based embedded/mobile deployments is routinely granted to a non-root firmware-management service or group. An unprivileged user holding a descriptor to that node can drive the entire path.\nUI:N - No victim action is needed — the attacker issues the ioctl himself, and the freeing side is driven by SVC module-removed events or the mode-switch timeout that the attacker can provoke. No file must be opened and no filesystem mounted by another user.\nS:U - The use-after-free corrupts kernel heap memory and is exploited within the same kernel security authority; there is no hypervisor, IOMMU, or sandbox boundary crossed. This is standard local kernel privilege escalation.\nC:H - The freed gb_interface can be reclaimed and sprayed by the attacker, after which gb_interface_mode_switch_work() reads intf->control, intf->enabled and walks intf->bundles, giving a controlled-pointer dereference usable as an arbitrary kernel-memory read primitive. Full disclosure of kernel memory, including credentials and KASLR-defeating pointers, is achievable.\nI:H - mutex_lock(&intf->mutex) on the freed object writes into attacker-controlled reclaimed memory, and gb_bundle_destroy() iterating the stale intf->bundles list performs list-unlink writes through attacker-supplied pointers. These are classic UAF write primitives that can be escalated to control-flow hijack and full kernel compromise.\nA:H - Even without successful reclaim, the work item dereferences and takes a mutex on freed memory, producing a kernel oops or panic. Any use-after-free of this kind reliably crashes the system, and the ioctl can be repeated to trigger it at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/greybus/interface.c" ], "versions": [ { "version": "55742d2a071a569bf20f90d37b1b5b8a25a3f882", "lessThan": "74cd0a421896b2e07eafe7da4275302bfecef201", "status": "affected", "versionType": "git" }, { "version": "55742d2a071a569bf20f90d37b1b5b8a25a3f882", "lessThan": "2b6bb0b4abfd79b8698ee161bb73c0936a2aaf83", "status": "affected", "versionType": "git" }, { "version": "55742d2a071a569bf20f90d37b1b5b8a25a3f882", "lessThan": "fb071f5c75d4b1c177824de74ee75f9dd34123b9", "status": "affected", "versionType": "git" }, { "version": "55742d2a071a569bf20f90d37b1b5b8a25a3f882", "lessThan": "9a733d69a4a59c2d08620e6589d823c24be773dc", "status": "affected", "versionType": "git" }, { "version": "55742d2a071a569bf20f90d37b1b5b8a25a3f882", "lessThan": "0b8fba38bdfb848fac52e71270b2aa3538c996ea", "status": "affected", "versionType": "git" }, { "version": "55742d2a071a569bf20f90d37b1b5b8a25a3f882", "lessThan": "03ea2b129344152157418929f06726989efc0445", "status": "affected", "versionType": "git" }, { "version": "55742d2a071a569bf20f90d37b1b5b8a25a3f882", "lessThan": "5c9c5d7f26acc2c669c1dcf57d1bb43ee99220ce", "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/greybus/interface.c" ], "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "lessThan": "4.9", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.279", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.221", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.162", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.95", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.35", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.9.6", "lessThanOrEqual": "6.9.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.10", "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": "4.9", "versionEndExcluding": "5.4.279" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.10.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.15.162" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.1.95" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.6.35" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.9.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.10" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/74cd0a421896b2e07eafe7da4275302bfecef201" }, { "url": "https://git.kernel.org/stable/c/2b6bb0b4abfd79b8698ee161bb73c0936a2aaf83" }, { "url": "https://git.kernel.org/stable/c/fb071f5c75d4b1c177824de74ee75f9dd34123b9" }, { "url": "https://git.kernel.org/stable/c/9a733d69a4a59c2d08620e6589d823c24be773dc" }, { "url": "https://git.kernel.org/stable/c/0b8fba38bdfb848fac52e71270b2aa3538c996ea" }, { "url": "https://git.kernel.org/stable/c/03ea2b129344152157418929f06726989efc0445" }, { "url": "https://git.kernel.org/stable/c/5c9c5d7f26acc2c669c1dcf57d1bb43ee99220ce" } ], "title": "greybus: Fix use-after-free bug in gb_interface_release due to race condition.", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/74cd0a421896b2e07eafe7da4275302bfecef201", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/2b6bb0b4abfd79b8698ee161bb73c0936a2aaf83", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/fb071f5c75d4b1c177824de74ee75f9dd34123b9", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/9a733d69a4a59c2d08620e6589d823c24be773dc", "tags": [ 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"other": { "type": "ssvc", "content": { "timestamp": "2024-08-16T04:02:11.550513Z", "id": "CVE-2024-39495", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-08-20T14:16:51.245Z" } } ] } }