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

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact total

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel
Redhat
  • Enterprise Linux

Configuration 1 [-]

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Package CPE Advisory Released Date
Red Hat Enterprise Linux 9
kernel-0:5.14.0-570.12.1.el9_6 cpe:/a:redhat:enterprise_linux:9 RHSA-2025:6966 2025-05-13T00:00:00Z
kernel-0:5.14.0-570.12.1.el9_6 cpe:/o:redhat:enterprise_linux:9 RHSA-2025:6966 2025-05-13T00:00:00Z
References
Link Providers
https://git.kernel.org/stable/c/1cecfdbc6bfc89c516d286884c7f29267b95de2b cve-icon cve-icon
https://git.kernel.org/stable/c/6cefcadd34e3c71c81ea64b899a0daa86314a51a cve-icon cve-icon
https://git.kernel.org/stable/c/7365d1f8de63cffdbbaa2287ce0205438e1a922f cve-icon cve-icon
https://git.kernel.org/stable/c/7d8f7816bebcd2e7400bb4d786eccb8f33c9f9ec cve-icon cve-icon
https://git.kernel.org/stable/c/7fd29d284b55c2274f7a748e6c5f25b4758b8da5 cve-icon cve-icon
https://git.kernel.org/stable/c/be8f982c369c965faffa198b46060f8853e0f1f0 cve-icon cve-icon
https://git.kernel.org/stable/c/e2fa0d0e327279a8defb87b263cd0bf288fd9261 cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html cve-icon
https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html cve-icon
https://lore.kernel.org/linux-cve-announce/2024122712-CVE-2024-56558-9fd9@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2024-56558 cve-icon
https://www.cve.org/CVERecord?id=CVE-2024-56558 cve-icon
History

Mon, 03 Nov 2025 21:30:00 +0000

Type Values Removed Values Added
References

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00025}

 epss

{'score': 0.00026}

Wed, 14 May 2025 02:30:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

Mon, 24 Mar 2025 18:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel

Tue, 11 Feb 2025 16:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

 ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Sat, 28 Dec 2024 13:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Fri, 27 Dec 2024 14:45:00 +0000

Type Values Removed Values Added
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
Title nfsd: make sure exp active before svc_export_show
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2024-12-27T14:23:03.902Z

Updated: 2025-11-03T20:49:29.154Z

Reserved: 2024-12-27T14:03:05.992Z

Link: CVE-2024-56558

cve-icon Vulnrichment

Updated: 2025-11-03T20:49:29.154Z

cve-icon NVD

Status : Modified

Published: 2024-12-27T15:15:14.633

Modified: 2025-11-03T21:17:54.340

Link: CVE-2024-56558

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-12-27T00:00:00Z

Links: CVE-2024-56558 - Bugzilla