{"id":"CVE-2025-68366","state":"PUBLISHED","title":"nbd: defer config unlock in nbd_genl_connect","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: defer config unlock in nbd_genl_connect\n\nThere is one use-after-free warning when running NBD_CMD_CONNECT and\nNBD_CLEAR_SOCK:\n\nnbd_genl_connect\n  nbd_alloc_and_init_config // config_refs=1\n  nbd_start_device // config_refs=2\n  set NBD_RT_HAS_CONFIG_REF\t\t\topen nbd // config_refs=3\n  recv_work done // config_refs=2\n\t\t\t\t\t\tNBD_CLEAR_SOCK // config_refs=1\n\t\t\t\t\t\tclose nbd // config_refs=0\n  refcount_inc -> uaf\n\n------------[ cut here ]------------\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 24 PID: 1014 at lib/refcount.c:25 refcount_warn_saturate+0x12e/0x290\n nbd_genl_connect+0x16d0/0x1ab0\n genl_family_rcv_msg_doit+0x1f3/0x310\n genl_rcv_msg+0x44a/0x790\n\nThe issue can be easily reproduced by adding a small delay before\nrefcount_inc(&nbd->config_refs) in nbd_genl_connect():\n\n        mutex_unlock(&nbd->config_lock);\n        if (!ret) {\n                set_bit(NBD_RT_HAS_CONFIG_REF, &config->runtime_flags);\n+               printk(\"before sleep\\n\");\n+               mdelay(5 * 1000);\n+               printk(\"after sleep\\n\");\n                refcount_inc(&nbd->config_refs);\n                nbd_connect_reply(info, nbd->index);\n        }","publishedAt":"2025-12-24T10:32:53.399Z","updatedAt":"2026-06-16T19:12:35.384Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"330d688a5ca53857828081a3cf31b92ad1b0b3ed","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"cd93db1b1b4460e6ee77564024ea461e5940f69c","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"ae3e7bc1f4b393ae20e5c85583eb2c6977374716","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"2e5e0665a594f076ef2b9439447bae8be293d09d","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"c9b99c948b4fb014812afe7b5ccf2db121d22e46","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"9a38306643874566d20f7aba7dff9e6f657b51a9","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"c9e805f6a35d1dd189a9345595a5c20e87611942","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"1649714b930f9ea6233ce0810ba885999da3b5d4","versionType":"git"}],"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":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","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/330d688a5ca53857828081a3cf31b92ad1b0b3ed","https://git.kernel.org/stable/c/cd93db1b1b4460e6ee77564024ea461e5940f69c","https://git.kernel.org/stable/c/ae3e7bc1f4b393ae20e5c85583eb2c6977374716","https://git.kernel.org/stable/c/2e5e0665a594f076ef2b9439447bae8be293d09d","https://git.kernel.org/stable/c/c9b99c948b4fb014812afe7b5ccf2db121d22e46","https://git.kernel.org/stable/c/9a38306643874566d20f7aba7dff9e6f657b51a9","https://git.kernel.org/stable/c/c9e805f6a35d1dd189a9345595a5c20e87611942","https://git.kernel.org/stable/c/1649714b930f9ea6233ce0810ba885999da3b5d4"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:56.034Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/68xxx/CVE-2025-68366.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-68366","state":"PUBLISHED","datePublished":"2025-12-24T10:32:53.399Z","dateUpdated":"2026-06-16T19:12:35.384Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-12-16T14:48:05.308Z"},"containers":{"cna":{"title":"nbd: defer config unlock in nbd_genl_connect","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: defer config unlock in nbd_genl_connect\n\nThere is one use-after-free warning when running NBD_CMD_CONNECT and\nNBD_CLEAR_SOCK:\n\nnbd_genl_connect\n  nbd_alloc_and_init_config // config_refs=1\n  nbd_start_device // config_refs=2\n  set NBD_RT_HAS_CONFIG_REF\t\t\topen nbd // config_refs=3\n  recv_work done // config_refs=2\n\t\t\t\t\t\tNBD_CLEAR_SOCK // config_refs=1\n\t\t\t\t\t\tclose nbd // config_refs=0\n  refcount_inc -> uaf\n\n------------[ cut here ]------------\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 24 PID: 1014 at lib/refcount.c:25 refcount_warn_saturate+0x12e/0x290\n nbd_genl_connect+0x16d0/0x1ab0\n genl_family_rcv_msg_doit+0x1f3/0x310\n genl_rcv_msg+0x44a/0x790\n\nThe issue can be easily reproduced by adding a small delay before\nrefcount_inc(&nbd->config_refs) in nbd_genl_connect():\n\n        mutex_unlock(&nbd->config_lock);\n        if (!ret) {\n                set_bit(NBD_RT_HAS_CONFIG_REF, &config->runtime_flags);\n+               printk(\"before sleep\\n\");\n+               mdelay(5 * 1000);\n+               printk(\"after sleep\\n\");\n                refcount_inc(&nbd->config_refs);\n                nbd_connect_reply(info, nbd->index);\n        }"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"330d688a5ca53857828081a3cf31b92ad1b0b3ed","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"cd93db1b1b4460e6ee77564024ea461e5940f69c","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"ae3e7bc1f4b393ae20e5c85583eb2c6977374716","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"2e5e0665a594f076ef2b9439447bae8be293d09d","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"c9b99c948b4fb014812afe7b5ccf2db121d22e46","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"9a38306643874566d20f7aba7dff9e6f657b51a9","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"c9e805f6a35d1dd189a9345595a5c20e87611942","versionType":"git"},{"version":"e46c7287b1c27683a8e30ca825fb98e2b97f1099","status":"affected","lessThan":"1649714b930f9ea6233ce0810ba885999da3b5d4","versionType":"git"}],"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":"4.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.12","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/330d688a5ca53857828081a3cf31b92ad1b0b3ed"},{"url":"https://git.kernel.org/stable/c/cd93db1b1b4460e6ee77564024ea461e5940f69c"},{"url":"https://git.kernel.org/stable/c/ae3e7bc1f4b393ae20e5c85583eb2c6977374716"},{"url":"https://git.kernel.org/stable/c/2e5e0665a594f076ef2b9439447bae8be293d09d"},{"url":"https://git.kernel.org/stable/c/c9b99c948b4fb014812afe7b5ccf2db121d22e46"},{"url":"https://git.kernel.org/stable/c/9a38306643874566d20f7aba7dff9e6f657b51a9"},{"url":"https://git.kernel.org/stable/c/c9e805f6a35d1dd189a9345595a5c20e87611942"},{"url":"https://git.kernel.org/stable/c/1649714b930f9ea6233ce0810ba885999da3b5d4"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:51:48.993Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.10.248"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.15.198"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.1.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.6.120"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.12.63"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.17.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.18.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.19"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-16T19:12:23.169488Z","id":"CVE-2025-68366","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":"2026-06-16T19:12:35.384Z"}}]}}}