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TI-2024-37444 Aliases CVE-2024-56558GHSA-r5pj-8mrw-4gqj

nfsd: make sure exp active before svc_export_show

Priority LOW 36CWE-416Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 5 fixed, 3 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00243 15th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.4.287, 5.10.231, 5.15.174 +4Red Hat: 1 advisoryRed Hat: 5 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux3.17 and later5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.12.4, 6.13Patch availableCNA
  • Linux VendorLinux Affected 3.17 and later Fixed in 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.12.4, 6.13 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*3.17 to before 5.4.287; 5.5 to before 5.10.231; 5.11 to before 5.15.174; 5.16 to before 6.1.120; 6.2 to before 6.6.64; 6.7 to before 6.12.4VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.17 to before 5.4.287; 5.5 to before 5.10.231; 5.11 to before 5.15.174; 5.16 to before 6.1.120; 6.2 to before 6.6.64; 6.7 to before 6.12.4 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.12.4, 6.13

Red Hat 1 advisory

  • RHSA-2025:6966 Released 2025-05-13 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-570.12.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.12.1.el9_6, kernel-64k-devel-5.14.0-570.12.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-570.12.1.el9_6, kernel-64k-5.14.0-570.12.1.el9_6, kernel-64k-core-5.14.0-570.12.1.el9_6 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-570.12.1.el9_6, libperf-5.14.0-570.12.1.el9_6
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-570.12.1.el9_6, kernel-rt-64k-5.14.0-570.12.1.el9_6, kernel-rt-64k-core-5.14.0-570.12.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-570.12.1.el9_6, kernel-rt-core-5.14.0-570.12.1.el9_6, kernel-rt-debug-5.14.0-570.12.1.el9_6 +11

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2025:6966
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2025:6966
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2025:6966
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2025:6966
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2025:6966

Timeline

  1. 2026-10-02 Threatist record created from CVE-2024-56558
  2. 2026-10-03 Alias added: GHSA-r5pj-8mrw-4gqj
  3. 2026-10-29 Affected versions changed · Red Hat

References

Patch 7

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences