{"id":"CVE-2024-56558","summary":"nfsd: make sure exp active before svc_export_show","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: make sure exp active before svc_export_show\n\nThe function `e_show` was called with protection from RCU. This only\nensures that `exp` will not be freed. Therefore, the reference count for\n`exp` can drop to zero, which will trigger a refcount use-after-free\nwarning when `exp_get` is called. To resolve this issue, use\n`cache_get_rcu` to ensure that `exp` remains active.\n\n------------[ cut here ]------------\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 3 PID: 819 at lib/refcount.c:25\nrefcount_warn_saturate+0xb1/0x120\nCPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS\n1.16.1-2.fc37 04/01/2014\nRIP: 0010:refcount_warn_saturate+0xb1/0x120\n...\nCall Trace:\n \u003cTASK\u003e\n e_show+0x20b/0x230 [nfsd]\n seq_read_iter+0x589/0x770\n seq_read+0x1e5/0x270\n vfs_read+0x125/0x530\n ksys_read+0xc1/0x160\n do_syscall_64+0x5f/0x170\n entry_SYSCALL_64_after_hwframe+0x76/0x7e","modified":"2026-04-03T13:14:39.288675Z","published":"2024-12-27T14:23:03.902Z","related":["SUSE-SU-2025:01918-1","SUSE-SU-2025:01966-1","SUSE-SU-2025:01982-1","SUSE-SU-2025:01995-1","SUSE-SU-2025:02173-1","SUSE-SU-2025:02262-1","SUSE-SU-2025:02387-1","SUSE-SU-2025:02388-1","SUSE-SU-2025:02389-1","SUSE-SU-2025:02390-1","SUSE-SU-2025:02398-1","SUSE-SU-2025:02399-1","SUSE-SU-2025:02400-1","SUSE-SU-2025:02401-1","SUSE-SU-2025:02403-1","SUSE-SU-2025:02410-1","SUSE-SU-2025:02411-1","SUSE-SU-2025:02412-1","SUSE-SU-2025:02416-1","SUSE-SU-2025:02418-1","SUSE-SU-2025:02419-1","SUSE-SU-2025:02420-1","SUSE-SU-2025:02428-1","SUSE-SU-2025:02433-1","SUSE-SU-2025:02434-1","SUSE-SU-2025:02436-1","SUSE-SU-2025:02440-1","SUSE-SU-2025:02444-1","SUSE-SU-2025:02445-1","SUSE-SU-2025:02446-1","SUSE-SU-2025:02449-1","SUSE-SU-2025:02451-1","SUSE-SU-2025:02454-1","SUSE-SU-2025:02455-1","SUSE-SU-2025:02456-1","SUSE-SU-2025:02459-1","SUSE-SU-2025:02467-1","SUSE-SU-2025:02468-1","SUSE-SU-2025:02469-1","SUSE-SU-2025:02470-1","SUSE-SU-2025:0289-1","SUSE-SU-2025:0428-1","SUSE-SU-2025:0499-1","SUSE-SU-2025:0556-1","SUSE-SU-2025:0557-1","SUSE-SU-2025:0577-1","SUSE-SU-2025:0577-2","SUSE-SU-2025:20165-1","SUSE-SU-2025:20166-1","SUSE-SU-2025:20248-1","SUSE-SU-2025:20249-1","SUSE-SU-2025:20517-1","SUSE-SU-2025:20518-1","SUSE-SU-2025:20519-1","SUSE-SU-2025:20525-1","SUSE-SU-2025:20526-1","SUSE-SU-2025:20527-1","SUSE-SU-2025:20540-1","SUSE-SU-2025:20541-1","SUSE-SU-2025:20544-1","SUSE-SU-2025:20545-1","USN-7379-2","USN-7380-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56558.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1cecfdbc6bfc89c516d286884c7f29267b95de2b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6cefcadd34e3c71c81ea64b899a0daa86314a51a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7365d1f8de63cffdbbaa2287ce0205438e1a922f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7d8f7816bebcd2e7400bb4d786eccb8f33c9f9ec"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7fd29d284b55c2274f7a748e6c5f25b4758b8da5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/be8f982c369c965faffa198b46060f8853e0f1f0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e2fa0d0e327279a8defb87b263cd0bf288fd9261"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56558.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-56558"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"bf18f163e89c52e09c96534db45c4274273a0b34"},{"fixed":"e2fa0d0e327279a8defb87b263cd0bf288fd9261"},{"fixed":"7fd29d284b55c2274f7a748e6c5f25b4758b8da5"},{"fixed":"6cefcadd34e3c71c81ea64b899a0daa86314a51a"},{"fixed":"7d8f7816bebcd2e7400bb4d786eccb8f33c9f9ec"},{"fixed":"1cecfdbc6bfc89c516d286884c7f29267b95de2b"},{"fixed":"7365d1f8de63cffdbbaa2287ce0205438e1a922f"},{"fixed":"be8f982c369c965faffa198b46060f8853e0f1f0"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-56558.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}