CVE-2024-56558

Advisory lineage Upstream: 0 Downstream: 100
Modified
Published: 27 Dec 2024, 14:23
Last modified:11 May 2026, 20:54

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.01% LOW
0% probability -0.02%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

27 Dec 2024, 14:23
Published
Vulnerability first disclosed
11 May 2026, 20:54
Last Modified
Vulnerability information updated

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

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 2%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • linux•linux

    ≥ bf18f163e89c52e09c96534db45c4274273a0b34, < e2fa0d0e327279a8defb87b263cd0bf288fd9261 | ≥ bf18f163e89c52e09c96534db45c4274273a0b34, < 7fd29d284b55c2274f7a748e6c5f25b4758b8da5 | ≥ bf18f163e89c52e09c96534db45c4274273a0b34, < 6cefcadd34e3c71c81ea64b899a0daa86314a51a | ≥ bf18f163e89c52e09c96534db45c4274273a0b34, < 7d8f7816bebcd2e7400bb4d786eccb8f33c9f9ec | ≥ bf18f163e89c52e09c96534db45c4274273a0b34, < 1cecfdbc6bfc89c516d286884c7f29267b95de2b | ≥ bf18f163e89c52e09c96534db45c4274273a0b34, < 7365d1f8de63cffdbbaa2287ce0205438e1a922f | ≥ bf18f163e89c52e09c96534db45c4274273a0b34, < be8f982c369c965faffa198b46060f8853e0f1f0 | 3.17

  • linux•linux_kernel

    ≥ 3.17, < 5.4.287 | ≥ 5.5, < 5.10.231 | ≥ 5.11, < 5.15.174 | ≥ 5.16, < 6.1.120 | ≥ 6.2, < 6.6.64 | ≥ 6.7, < 6.12.4

References (9)