{"id":"CVE-2024-50121","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-50121","generatedAt":"2026-10-28T00:17:47.573Z","title":"In the Linux kernel, the following vulnerability has been resolved: nfsd: cancel nfsd_shrinker_work using sync mode in nfs4_state_shutdown_net In the normal case, when we excute `echo 0 > /proc/fs/nfsd/threads`, the function `nfs4_state_destroy_net` in…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: cancel nfsd_shrinker_work using sync mode in nfs4_state_shutdown_net\n\nIn the normal case, when we excute `echo 0 > /proc/fs/nfsd/threads`, the\nfunction `nfs4_state_destroy_net` in `nfs4_state_shutdown_net` will\nrelease all resources related to the hashed `nfs4_client`. If the\n`nfsd_client_shrinker` is running concurrently, the `expire_client`\nfunction will first unhash this client and then destroy it. This can\nlead to the following warning. Additionally, numerous use-after-free\nerrors may occur as well.\n\nnfsd_client_shrinker         echo 0 > /proc/fs/nfsd/threads\n\nexpire_client                nfsd_shutdown_net\n  unhash_client                ...\n                               nfs4_state_shutdown_net\n                                 /* won't wait shrinker exit */\n  /*                             cancel_work(&nn->nfsd_shrinker_work)\n   * nfsd_file for this          /* won't destroy unhashed client1 */\n   * client1 still alive         nfs4_state_destroy_net\n   */\n\n                               nfsd_file_cache_shutdown\n                                 /* trigger warning */\n                                 kmem_cache_destroy(nfsd_file_slab)\n                                 kmem_cache_destroy(nfsd_file_mark_slab)\n  /* release nfsd_file and mark */\n  __destroy_client\n\n====================================================================\nBUG nfsd_file (Not tainted): Objects remaining in nfsd_file on\n__kmem_cache_shutdown()\n--------------------------------------------------------------------\nCPU: 4 UID: 0 PID: 764 Comm: sh Not tainted 6.12.0-rc3+ #1\n\n dump_stack_lvl+0x53/0x70\n slab_err+0xb0/0xf0\n __kmem_cache_shutdown+0x15c/0x310\n kmem_cache_destroy+0x66/0x160\n nfsd_file_cache_shutdown+0xac/0x210 [nfsd]\n nfsd_destroy_serv+0x251/0x2a0 [nfsd]\n nfsd_svc+0x125/0x1e0 [nfsd]\n write_threads+0x16a/0x2a0 [nfsd]\n nfsctl_transaction_write+0x74/0xa0 [nfsd]\n vfs_write+0x1a5/0x6d0\n ksys_write+0xc1/0x160\n do_syscall_64+0x5f/0x170\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\n====================================================================\nBUG nfsd_file_mark (Tainted: G    B   W         ): Objects remaining\nnfsd_file_mark on __kmem_cache_shutdown()\n--------------------------------------------------------------------\n\n dump_stack_lvl+0x53/0x70\n slab_err+0xb0/0xf0\n __kmem_cache_shutdown+0x15c/0x310\n kmem_cache_destroy+0x66/0x160\n nfsd_file_cache_shutdown+0xc8/0x210 [nfsd]\n nfsd_destroy_serv+0x251/0x2a0 [nfsd]\n nfsd_svc+0x125/0x1e0 [nfsd]\n write_threads+0x16a/0x2a0 [nfsd]\n nfsctl_transaction_write+0x74/0xa0 [nfsd]\n vfs_write+0x1a5/0x6d0\n ksys_write+0xc1/0x160\n do_syscall_64+0x5f/0x170\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nTo resolve this issue, cancel `nfsd_shrinker_work` using synchronous\nmode in nfs4_state_shutdown_net.","published":"2024-11-05T18:15:15.000Z","lastModified":"2026-10-15T01:19:07.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-416"],"affected":["linux/linux kernel"],"epss":{"score":0.00236,"percentile":0.1444,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/36775f42e039b01d4abe8998bf66771a37d3cdcc","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5ade4382de16c34d9259cb548f36ec5c4555913c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/add1df5eba163a3a6ece11cb85890e2e410baaea","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d5ff2fb2e7167e9483846e34148e60c0c016a1f6","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f67138dd338cb564ade7d3755c8cd4f68b46d397","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f965dc0f099a54fca100acf6909abe52d0c85328","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","source":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-50121","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}