{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-55916", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-01-09T09:49:29.678Z", "datePublished": "2025-01-11T12:35:44.800Z", "dateUpdated": "2026-05-11T20:53:57.302Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T20:53:57.302Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nDrivers: hv: util: Avoid accessing a ringbuffer not initialized yet\n\nIf the KVP (or VSS) daemon starts before the VMBus channel's ringbuffer is\nfully initialized, we can hit the panic below:\n\nhv_utils: Registering HyperV Utility Driver\nhv_vmbus: registering driver hv_utils\n...\nBUG: kernel NULL pointer dereference, address: 0000000000000000\nCPU: 44 UID: 0 PID: 2552 Comm: hv_kvp_daemon Tainted: G E 6.11.0-rc3+ #1\nRIP: 0010:hv_pkt_iter_first+0x12/0xd0\nCall Trace:\n...\n vmbus_recvpacket\n hv_kvp_onchannelcallback\n vmbus_on_event\n tasklet_action_common\n tasklet_action\n handle_softirqs\n irq_exit_rcu\n sysvec_hyperv_stimer0\n \n \n asm_sysvec_hyperv_stimer0\n...\n kvp_register_done\n hvt_op_read\n vfs_read\n ksys_read\n __x64_sys_read\n\nThis can happen because the KVP/VSS channel callback can be invoked\neven before the channel is fully opened:\n1) as soon as hv_kvp_init() -> hvutil_transport_init() creates\n/dev/vmbus/hv_kvp, the kvp daemon can open the device file immediately and\nregister itself to the driver by writing a message KVP_OP_REGISTER1 to the\nfile (which is handled by kvp_on_msg() ->kvp_handle_handshake()) and\nreading the file for the driver's response, which is handled by\nhvt_op_read(), which calls hvt->on_read(), i.e. kvp_register_done().\n\n2) the problem with kvp_register_done() is that it can cause the\nchannel callback to be called even before the channel is fully opened,\nand when the channel callback is starting to run, util_probe()->\nvmbus_open() may have not initialized the ringbuffer yet, so the\ncallback can hit the panic of NULL pointer dereference.\n\nTo reproduce the panic consistently, we can add a \"ssleep(10)\" for KVP in\n__vmbus_open(), just before the first hv_ringbuffer_init(), and then we\nunload and reload the driver hv_utils, and run the daemon manually within\nthe 10 seconds.\n\nFix the panic by reordering the steps in util_probe() so the char dev\nentry used by the KVP or VSS daemon is not created until after\nvmbus_open() has completed. This reordering prevents the race condition\nfrom happening." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/hv/hv_kvp.c", "drivers/hv/hv_snapshot.c", "drivers/hv/hv_util.c", "drivers/hv/hyperv_vmbus.h", "include/linux/hyperv.h" ], "versions": [ { "version": "e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c", "lessThan": "f091a224a2c82f1e302b1768d73bb6332f687321", "status": "affected", "versionType": "git" }, { "version": "e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c", "lessThan": "d81f4e73aff9b861671df60e5100ad25cc16fbf8", "status": "affected", "versionType": "git" }, { "version": "e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c", "lessThan": "042253c57be901bfd19f15b68267442b70f510d5", "status": "affected", "versionType": "git" }, { "version": "e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c", "lessThan": "718fe694a334be9d1a89eed22602369ac18d6583", "status": "affected", "versionType": "git" }, { "version": "e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c", "lessThan": "89fcec5e466b3ac9b376e0d621c71effa1a7983f", "status": "affected", "versionType": "git" }, { "version": "e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c", "lessThan": "3dd7a30c6d7f90afcf19e9b072f572ba524d7ec6", "status": "affected", "versionType": "git" }, { "version": "e0fa3e5e7df61eb2c339c9f0067c202c0cdeec2c", "lessThan": "07a756a49f4b4290b49ea46e089cbe6f79ff8d26", "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/hv/hv_kvp.c", "drivers/hv/hv_snapshot.c", "drivers/hv/hv_util.c", "drivers/hv/hyperv_vmbus.h", "include/linux/hyperv.h" ], "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "lessThan": "4.9", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.289", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.233", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.176", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.122", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.68", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.7", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13", "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": "5.4.289" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.10.233" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.15.176" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.1.122" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.6.68" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.12.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f091a224a2c82f1e302b1768d73bb6332f687321" }, { "url": "https://git.kernel.org/stable/c/d81f4e73aff9b861671df60e5100ad25cc16fbf8" }, { "url": "https://git.kernel.org/stable/c/042253c57be901bfd19f15b68267442b70f510d5" }, { "url": "https://git.kernel.org/stable/c/718fe694a334be9d1a89eed22602369ac18d6583" }, { "url": "https://git.kernel.org/stable/c/89fcec5e466b3ac9b376e0d621c71effa1a7983f" }, { "url": "https://git.kernel.org/stable/c/3dd7a30c6d7f90afcf19e9b072f572ba524d7ec6" }, { "url": "https://git.kernel.org/stable/c/07a756a49f4b4290b49ea46e089cbe6f79ff8d26" } ], "title": "Drivers: hv: util: Avoid accessing a ringbuffer not initialized yet", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2024-55916", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2025-10-01T19:55:21.065122Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-476", "description": "CWE-476 NULL Pointer Dereference" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-01T19:57:21.020Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T20:48:52.286Z" } } ] } }