{"id":"CVE-2025-68372","state":"PUBLISHED","title":"nbd: defer config put in recv_work","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: defer config put in recv_work\n\nThere is one uaf issue in recv_work when running NBD_CLEAR_SOCK and\nNBD_CMD_RECONFIGURE:\n  nbd_genl_connect     // conf_ref=2 (connect and recv_work A)\n  nbd_open\t       // conf_ref=3\n  recv_work A done     // conf_ref=2\n  NBD_CLEAR_SOCK       // conf_ref=1\n  nbd_genl_reconfigure // conf_ref=2 (trigger recv_work B)\n  close nbd\t       // conf_ref=1\n  recv_work B\n    config_put         // conf_ref=0\n    atomic_dec(&config->recv_threads); -> UAF\n\nOr only running NBD_CLEAR_SOCK:\n  nbd_genl_connect   // conf_ref=2\n  nbd_open \t     // conf_ref=3\n  NBD_CLEAR_SOCK     // conf_ref=2\n  close nbd\n    nbd_release\n      config_put     // conf_ref=1\n  recv_work\n    config_put \t     // conf_ref=0\n    atomic_dec(&config->recv_threads); -> UAF\n\nCommit 87aac3a80af5 (\"nbd: call nbd_config_put() before notifying the\nwaiter\") moved nbd_config_put() to run before waking up the waiter in\nrecv_work, in order to ensure that nbd_start_device_ioctl() would not\nbe woken up while nbd->task_recv was still uncleared.\n\nHowever, in nbd_start_device_ioctl(), after being woken up it explicitly\ncalls flush_workqueue() to make sure all current works are finished.\nTherefore, there is no need to move the config put ahead of the wakeup.\n\nMove nbd_config_put() to the end of recv_work, so that the reference is\nheld for the whole lifetime of the worker thread. This makes sure the\nconfig cannot be freed while recv_work is still running, even if clear\n+ reconfigure interleave.\n\nIn addition, we don't need to worry about recv_work dropping the last\nnbd_put (which causes deadlock):\n\npath A (netlink with NBD_CFLAG_DESTROY_ON_DISCONNECT):\n  connect  // nbd_refs=1 (trigger recv_work)\n  open nbd // nbd_refs=2\n  NBD_CLEAR_SOCK\n  close nbd\n    nbd_release\n      nbd_disconnect_and_put\n        flush_workqueue // recv_work done\n      nbd_config_put\n        nbd_put // nbd_refs=1\n      nbd_put // nbd_refs=0\n        queue_work\n\npath B (netlink without NBD_CFLAG_DESTROY_ON_DISCONNECT):\n  connect  // nbd_refs=2 (trigger recv_work)\n  open nbd // nbd_refs=3\n  NBD_CLEAR_SOCK // conf_refs=2\n  close nbd\n    nbd_release\n      nbd_config_put // conf_refs=1\n      nbd_put // nbd_refs=2\n  recv_work done // conf_refs=0, nbd_refs=1\n  rmmod // nbd_refs=0\n\nDepends-on: e2daec488c57 (\"nbd: Fix hungtask when nbd_config_put\")","publishedAt":"2025-12-24T10:33:02.679Z","updatedAt":"2026-06-16T19:28:42.649Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"198aa230a6f8c1f6af7ed26b29180749c3e79e4d","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"d3ba312675911ff9e3fefefd551751e153a9f0a9","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"3692884bd6187d89d41eef81e5a9724519fd01c1","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"1ba2ced2bbdf7e64a30c3e88c70ea8bc208d1509","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"6b69593f72e1bfba6ca47ca8d9b619341fded7d6","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"443a1721806b6ff6303b5229e9811d68172d622f","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"742012f6bf29553fdc460bf646a58df3a7b43d01","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"9517b82d8d422d426a988b213fdd45c6b417b86d","versionType":"git"},{"version":"0a4e383fc3aa6540f804c4fd1184a96ae5de6ef8","status":"affected","versionType":"git"},{"version":"2ef6f4bd60411934e3fc2715442c2afe70f84bf3","status":"affected","versionType":"git"},{"version":"742fd49cf811ca164489e339b862e3fb8e240a73","status":"affected","versionType":"git"},{"version":"14df8724aeeef338172e2a2d6efadc989921ca0f","status":"affected","versionType":"git"},{"version":"4.14.204","status":"affected","lessThan":"4.15","versionType":"semver"},{"version":"4.19.155","status":"affected","lessThan":"4.20","versionType":"semver"},{"version":"5.4.75","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"5.9.5","status":"affected","lessThan":"5.10","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/nbd.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.10.248","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.198","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.160","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.120","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.63","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.13","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18.2","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/nbd.c"]}],"references":["https://git.kernel.org/stable/c/198aa230a6f8c1f6af7ed26b29180749c3e79e4d","https://git.kernel.org/stable/c/d3ba312675911ff9e3fefefd551751e153a9f0a9","https://git.kernel.org/stable/c/3692884bd6187d89d41eef81e5a9724519fd01c1","https://git.kernel.org/stable/c/1ba2ced2bbdf7e64a30c3e88c70ea8bc208d1509","https://git.kernel.org/stable/c/6b69593f72e1bfba6ca47ca8d9b619341fded7d6","https://git.kernel.org/stable/c/443a1721806b6ff6303b5229e9811d68172d622f","https://git.kernel.org/stable/c/742012f6bf29553fdc460bf646a58df3a7b43d01","https://git.kernel.org/stable/c/9517b82d8d422d426a988b213fdd45c6b417b86d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:56.034Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/68xxx/CVE-2025-68372.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-68372","state":"PUBLISHED","datePublished":"2025-12-24T10:33:02.679Z","dateUpdated":"2026-06-16T19:28:42.649Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-12-16T14:48:05.310Z"},"containers":{"cna":{"title":"nbd: defer config put in recv_work","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: defer config put in recv_work\n\nThere is one uaf issue in recv_work when running NBD_CLEAR_SOCK and\nNBD_CMD_RECONFIGURE:\n  nbd_genl_connect     // conf_ref=2 (connect and recv_work A)\n  nbd_open\t       // conf_ref=3\n  recv_work A done     // conf_ref=2\n  NBD_CLEAR_SOCK       // conf_ref=1\n  nbd_genl_reconfigure // conf_ref=2 (trigger recv_work B)\n  close nbd\t       // conf_ref=1\n  recv_work B\n    config_put         // conf_ref=0\n    atomic_dec(&config->recv_threads); -> UAF\n\nOr only running NBD_CLEAR_SOCK:\n  nbd_genl_connect   // conf_ref=2\n  nbd_open \t     // conf_ref=3\n  NBD_CLEAR_SOCK     // conf_ref=2\n  close nbd\n    nbd_release\n      config_put     // conf_ref=1\n  recv_work\n    config_put \t     // conf_ref=0\n    atomic_dec(&config->recv_threads); -> UAF\n\nCommit 87aac3a80af5 (\"nbd: call nbd_config_put() before notifying the\nwaiter\") moved nbd_config_put() to run before waking up the waiter in\nrecv_work, in order to ensure that nbd_start_device_ioctl() would not\nbe woken up while nbd->task_recv was still uncleared.\n\nHowever, in nbd_start_device_ioctl(), after being woken up it explicitly\ncalls flush_workqueue() to make sure all current works are finished.\nTherefore, there is no need to move the config put ahead of the wakeup.\n\nMove nbd_config_put() to the end of recv_work, so that the reference is\nheld for the whole lifetime of the worker thread. This makes sure the\nconfig cannot be freed while recv_work is still running, even if clear\n+ reconfigure interleave.\n\nIn addition, we don't need to worry about recv_work dropping the last\nnbd_put (which causes deadlock):\n\npath A (netlink with NBD_CFLAG_DESTROY_ON_DISCONNECT):\n  connect  // nbd_refs=1 (trigger recv_work)\n  open nbd // nbd_refs=2\n  NBD_CLEAR_SOCK\n  close nbd\n    nbd_release\n      nbd_disconnect_and_put\n        flush_workqueue // recv_work done\n      nbd_config_put\n        nbd_put // nbd_refs=1\n      nbd_put // nbd_refs=0\n        queue_work\n\npath B (netlink without NBD_CFLAG_DESTROY_ON_DISCONNECT):\n  connect  // nbd_refs=2 (trigger recv_work)\n  open nbd // nbd_refs=3\n  NBD_CLEAR_SOCK // conf_refs=2\n  close nbd\n    nbd_release\n      nbd_config_put // conf_refs=1\n      nbd_put // nbd_refs=2\n  recv_work done // conf_refs=0, nbd_refs=1\n  rmmod // nbd_refs=0\n\nDepends-on: e2daec488c57 (\"nbd: Fix hungtask when nbd_config_put\")"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"198aa230a6f8c1f6af7ed26b29180749c3e79e4d","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"d3ba312675911ff9e3fefefd551751e153a9f0a9","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"3692884bd6187d89d41eef81e5a9724519fd01c1","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"1ba2ced2bbdf7e64a30c3e88c70ea8bc208d1509","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"6b69593f72e1bfba6ca47ca8d9b619341fded7d6","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"443a1721806b6ff6303b5229e9811d68172d622f","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"742012f6bf29553fdc460bf646a58df3a7b43d01","versionType":"git"},{"version":"87aac3a80af5cbad93e63250e8a1e19095ba0d30","status":"affected","lessThan":"9517b82d8d422d426a988b213fdd45c6b417b86d","versionType":"git"},{"version":"0a4e383fc3aa6540f804c4fd1184a96ae5de6ef8","status":"affected","versionType":"git"},{"version":"2ef6f4bd60411934e3fc2715442c2afe70f84bf3","status":"affected","versionType":"git"},{"version":"742fd49cf811ca164489e339b862e3fb8e240a73","status":"affected","versionType":"git"},{"version":"14df8724aeeef338172e2a2d6efadc989921ca0f","status":"affected","versionType":"git"},{"version":"4.14.204","status":"affected","lessThan":"4.15","versionType":"semver"},{"version":"4.19.155","status":"affected","lessThan":"4.20","versionType":"semver"},{"version":"5.4.75","status":"affected","lessThan":"5.5","versionType":"semver"},{"version":"5.9.5","status":"affected","lessThan":"5.10","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/nbd.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.10.248","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.198","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.160","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.120","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.63","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.17.13","status":"unaffected","lessThanOrEqual":"6.17.*","versionType":"semver"},{"version":"6.18.2","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/block/nbd.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/198aa230a6f8c1f6af7ed26b29180749c3e79e4d"},{"url":"https://git.kernel.org/stable/c/d3ba312675911ff9e3fefefd551751e153a9f0a9"},{"url":"https://git.kernel.org/stable/c/3692884bd6187d89d41eef81e5a9724519fd01c1"},{"url":"https://git.kernel.org/stable/c/1ba2ced2bbdf7e64a30c3e88c70ea8bc208d1509"},{"url":"https://git.kernel.org/stable/c/6b69593f72e1bfba6ca47ca8d9b619341fded7d6"},{"url":"https://git.kernel.org/stable/c/443a1721806b6ff6303b5229e9811d68172d622f"},{"url":"https://git.kernel.org/stable/c/742012f6bf29553fdc460bf646a58df3a7b43d01"},{"url":"https://git.kernel.org/stable/c/9517b82d8d422d426a988b213fdd45c6b417b86d"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T16:02:46.914Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.10.248"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.15.198"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.1.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.6.120"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.12.63"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.17.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*: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ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-16T19:28:28.671225Z","id":"CVE-2025-68372","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-16T19:28:42.649Z"}}]}}}