CVE-2024-56558nfsd: make sure exp active before svc_export_show
- 7.8HighCVSS base score
- 0.24%Exploitation in 30 daysEPSS · top 84% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: make sure exp active before svc_export_show The function `e_show` was called with protection from RCU. This only ensures that `exp` will not be freed. Therefore, the reference count for `exp` can drop to zero, which will trigger a refcount use-after-free warning when `exp_get` is called. To resolve this issue, use `cache_get_rcu` to ensure that `exp` remains active. ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 819 at lib/refcount.c:25 refcount_warn_saturate+0xb1/0x120 CPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:refcount_warn_saturate+0xb1/0x120 ... Call Trace: <TASK> e_show+0x20b/0x230 [nfsd] seq_read_iter+0x589/0x770 seq_read+0x1e5/0x270 vfs_read+0x125/0x530 ksys_read+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e
Timeline
ID reserved
By Linux
Published
- 20 months later
· 20 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CISA-ADPADP (enrichment) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.24% · top 84% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected bf18f163e89c52e09c96534db45c4274273a0b34 – < e2fa0d0e327279a8defb87b263cd0bf288fd9261
- affected bf18f163e89c52e09c96534db45c4274273a0b34 – < 7fd29d284b55c2274f7a748e6c5f25b4758b8da5
- affected bf18f163e89c52e09c96534db45c4274273a0b34 – < 6cefcadd34e3c71c81ea64b899a0daa86314a51a
- affected bf18f163e89c52e09c96534db45c4274273a0b34 – < 7d8f7816bebcd2e7400bb4d786eccb8f33c9f9ec
- affected bf18f163e89c52e09c96534db45c4274273a0b34 – < 1cecfdbc6bfc89c516d286884c7f29267b95de2b
- affected bf18f163e89c52e09c96534db45c4274273a0b34 – < 7365d1f8de63cffdbbaa2287ce0205438e1a922f
- affected bf18f163e89c52e09c96534db45c4274273a0b34 – < be8f982c369c965faffa198b46060f8853e0f1f0
- affected 3.17
- unaffected < 3.17
- unaffected 5.4.287 – ≤ 5.4.*
- unaffected 5.10.231 – ≤ 5.10.*
- unaffected 5.15.174 – ≤ 5.15.*
- unaffected 6.1.120 – ≤ 6.1.*
- unaffected 6.6.64 – ≤ 6.6.*
- unaffected 6.12.4 – ≤ 6.12.*
- unaffected 6.13 – ≤ *
References
References9
- https://git.kernel.org/stable/c/e2fa0d0e327279a8defb87b263cd0bf288fd9261 (opens in a new tab)
- https://git.kernel.org/stable/c/7fd29d284b55c2274f7a748e6c5f25b4758b8da5 (opens in a new tab)
- https://git.kernel.org/stable/c/6cefcadd34e3c71c81ea64b899a0daa86314a51a (opens in a new tab)
- https://git.kernel.org/stable/c/7d8f7816bebcd2e7400bb4d786eccb8f33c9f9ec (opens in a new tab)
- https://git.kernel.org/stable/c/1cecfdbc6bfc89c516d286884c7f29267b95de2b (opens in a new tab)
- https://git.kernel.org/stable/c/7365d1f8de63cffdbbaa2287ce0205438e1a922f (opens in a new tab)
- https://git.kernel.org/stable/c/be8f982c369c965faffa198b46060f8853e0f1f0 (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html (opens in a new tab)
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2024-53206 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2024-56558)Record last updated .