CVE-2025-38400 | nfs: Clean up /proc/net/rpc/nfs when nfs_fs_proc_net_init() fails.

In the Linux kernel, the following vulnerability has been resolved: nfs: Clean up /proc/net/rpc/nfs when nfs_fs_proc_net_init() fails. syzbot reported a warning below [1] following a fault injection in nfs_fs_proc_net_init(). [0] When nfs_fs_proc_net_init() fails, /proc/net/rpc/nfs is not removed. Later, rpc_proc_exit() tries to remove /proc/net/rpc, and the warning is logged as the directory is not empty. Let's handle the error of nfs_fs_proc_net_init() properly. [0]: FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 CPU: 1 UID: 0 PID: 6120 Comm: syz.2.27 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:123) should_fail_ex (lib/fault-inject.c:73 lib/fault-inject.c:174) should_failslab (mm/failslab.c:46) kmem_cache_alloc_noprof (mm/slub.c:4178 mm/slub.c:4204) __proc_create (fs/proc/generic.c:427) proc_create_reg (fs/proc/generic.c:554) proc_create_net_data (fs/proc/proc_net.c:120) nfs_fs_proc_net_init (fs/nfs/client.c:1409) nfs_net_init (fs/nfs/inode.c:2600) ops_init (net/core/net_namespace.c:138) setup_net (net/core/net_namespace.c:443) copy_net_ns (net/core/net_namespace.c:576) create_new_namespaces (kernel/nsproxy.c:110) unshare_nsproxy_namespaces (kernel/nsproxy.c:218 (discriminator 4)) ksys_unshare (kernel/fork.c:3123) __x64_sys_unshare (kernel/fork.c:3190) do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) </TASK> [1]: remove_proc_entry: removing non-empty directory 'net/rpc', leaking at least 'nfs' WARNING: CPU: 1 PID: 6120 at fs/proc/generic.c:727 remove_proc_entry+0x45e/0x530 fs/proc/generic.c:727 Modules linked in: CPU: 1 UID: 0 PID: 6120 Comm: syz.2.27 Not tainted 6.16.0-rc1-syzkaller-00010-g2c4a1f3fe03e #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:remove_proc_entry+0x45e/0x530 fs/proc/generic.c:727 Code: 3c 02 00 0f 85 85 00 00 00 48 8b 93 d8 00 00 00 4d 89 f0 4c 89 e9 48 c7 c6 40 ba a2 8b 48 c7 c7 60 b9 a2 8b e8 33 81 1d ff 90 <0f> 0b 90 90 e9 5f fe ff ff e8 04 69 5e ff 90 48 b8 00 00 00 00 00 RSP: 0018:ffffc90003637b08 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff88805f534140 RCX: ffffffff817a92c8 RDX: ffff88807da99e00 RSI: ffffffff817a92d5 RDI: 0000000000000001 RBP: ffff888033431ac0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888033431a00 R13: ffff888033431ae4 R14: ffff888033184724 R15: dffffc0000000000 FS: 0000555580328500(0000) GS:ffff888124a62000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f71733743e0 CR3: 000000007f618000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> sunrpc_exit_net+0x46/0x90 net/sunrpc/sunrpc_syms.c:76 ops_exit_list net/core/net_namespace.c:200 [inline] ops_undo_list+0x2eb/0xab0 net/core/net_namespace.c:253 setup_net+0x2e1/0x510 net/core/net_namespace.c:457 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:574 create_new_namespaces+0x3ea/0xa90 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:218 ksys_unshare+0x45b/0xa40 kernel/fork.c:3121 __do_sys_unshare kernel/fork.c:3192 [inline] __se_sys_unshare kernel/fork.c:3190 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3190 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa1a6b8e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c ---truncated---

Published: 2025-07-25 Last update: 2026-05-12 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-38400 is rated Low Risk (24.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.18%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-38400

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.06% 0.18% +0.11%
2 2026-05-21 0.04% 0.06% +0.02%
3 2025-12-21 0.04%

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-38400

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]

Weakness enumeration for CVE-2025-38400

GitHub Security Advisory for CVE-2025-38400

GHSA-ch6p-gm8m-r8fm · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: nfs: Clean up /proc/net/rpc...

OS Trackers for CVE-2025-38400

vendor priority summary link
debian not yet assigned CVE-2025-38400 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-38400
redhat low https://access.redhat.com/security/cve/CVE-2025-38400
suse medium CVE-2025-38400 severity moderate: SUSE including 475 source package names (2.1.3-6.67:kernel-default-base-6.4.0-32.1.21.10, 2.1.3-7.44:kernel-default-6.4.0-32.1, …), 1061 product×package rows across 210 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (210 product lines)): Fixed 627, Known Affected 231, Known Not Affected 182, First Fixed 21. https://www.suse.com/security/cve/CVE-2025-38400/
ubuntu medium CVE-2025-38400 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, released 170, ignored 155, not-affected 44, needed 25, needs-triage 2, pending 1. https://ubuntu.com/security/CVE-2025-38400

Affected software / configurations for CVE-2025-38400

Vendor Product Version Raw CPE
linux linux_kernel >= 5.4.276, < 5.4.296 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.10.217, < 5.10.240 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.15.159, < 5.15.187 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.1.91, < 6.1.144 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.6.31, < 6.6.97 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.8.10, < 6.12.37 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.15.6 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel 6.16 cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*
linux linux_kernel 6.16 cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*
linux linux_kernel 6.16 cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*
linux linux_kernel 6.16 cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-38400

URL Tags
https://git.kernel.org/stable/c/3c94212b57bedec3a386ef3da1ef00602f5c3d1d Patch
https://git.kernel.org/stable/c/412534a1fb76958b88dca48360c6f3ad4f3390f4 Patch
https://git.kernel.org/stable/c/6acf340f8c1d296bcf535986175f5d0d6f2aab09 Patch
https://git.kernel.org/stable/c/7701c245ff1ac1a126bf431e72b24547519046ff Patch
https://git.kernel.org/stable/c/8785701fd7cd52ae74c0d2b35b82568df74e9dbb Patch
https://git.kernel.org/stable/c/b92397ce96743e4cc090207e2df2a856cb4cef08 Patch
https://git.kernel.org/stable/c/d0877c479f44fe475f4c8c02c88ce9ad43e90298 Patch
https://git.kernel.org/stable/c/e8d6f3ab59468e230f3253efe5cb63efa35289f7 Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
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