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EUVD-2026-364514
European Vulnerability Database identifier assigned by ENISAReserved
2026-10-02 08:32
Assigner
ENISA
Alias of
a CVE record, shown under related vulnerabilities.
This identifier carries no description, severity or references of its own:
they belong to that CVE.
{
"assigner": "ENISA",
"date_reserved": "2026-10-02T08:32:46.234505+00:00",
"id": "EUVD-2026-364514"
}
CVE-2025-21999 (GCVE-0-2025-21999)
Vulnerability from cvelistv5 – Published: 2025-04-03 07:19 – Updated: 2026-09-08 08:41
VLAI
EPSS
VEX
Title
proc: fix UAF in proc_get_inode()
Summary
In the Linux kernel, the following vulnerability has been resolved:
proc: fix UAF in proc_get_inode()
Fix race between rmmod and /proc/XXX's inode instantiation.
The bug is that pde->proc_ops don't belong to /proc, it belongs to a
module, therefore dereferencing it after /proc entry has been registered
is a bug unless use_pde/unuse_pde() pair has been used.
use_pde/unuse_pde can be avoided (2 atomic ops!) because pde->proc_ops
never changes so information necessary for inode instantiation can be
saved _before_ proc_register() in PDE itself and used later, avoiding
pde->proc_ops->... dereference.
rmmod lookup
sys_delete_module
proc_lookup_de
pde_get(de);
proc_get_inode(dir->i_sb, de);
mod->exit()
proc_remove
remove_proc_subtree
proc_entry_rundown(de);
free_module(mod);
if (S_ISREG(inode->i_mode))
if (de->proc_ops->proc_read_iter)
--> As module is already freed, will trigger UAF
BUG: unable to handle page fault for address: fffffbfff80a702b
PGD 817fc4067 P4D 817fc4067 PUD 817fc0067 PMD 102ef4067 PTE 0
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 26 UID: 0 PID: 2667 Comm: ls Tainted: G
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
RIP: 0010:proc_get_inode+0x302/0x6e0
RSP: 0018:ffff88811c837998 EFLAGS: 00010a06
RAX: dffffc0000000000 RBX: ffffffffc0538140 RCX: 0000000000000007
RDX: 1ffffffff80a702b RSI: 0000000000000001 RDI: ffffffffc0538158
RBP: ffff8881299a6000 R08: 0000000067bbe1e5 R09: 1ffff11023906f20
R10: ffffffffb560ca07 R11: ffffffffb2b43a58 R12: ffff888105bb78f0
R13: ffff888100518048 R14: ffff8881299a6004 R15: 0000000000000001
FS: 00007f95b9686840(0000) GS:ffff8883af100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff80a702b CR3: 0000000117dd2000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
proc_lookup_de+0x11f/0x2e0
__lookup_slow+0x188/0x350
walk_component+0x2ab/0x4f0
path_lookupat+0x120/0x660
filename_lookup+0x1ce/0x560
vfs_statx+0xac/0x150
__do_sys_newstat+0x96/0x110
do_syscall_64+0x5f/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
[adobriyan@gmail.com: don't do 2 atomic ops on the common path]
Severity
7.8 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-04-03 15:26 UTC
CWE
- CWE-416 - Use After Free
Assigner
References
10 references
Impacted products
5 products
| Vendor | Product | Version | |
|---|---|---|---|
| Linux | Linux |
Affected:
97a32539b9568bb653683349e5a76d02ff3c3e2c , < eda279586e571b05dff44d48e05f8977ad05855d
(git)
Affected: 97a32539b9568bb653683349e5a76d02ff3c3e2c , < 4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa (git) Affected: 97a32539b9568bb653683349e5a76d02ff3c3e2c , < 966f331403dc3ed04ff64eaf3930cf1267965e53 (git) Affected: 97a32539b9568bb653683349e5a76d02ff3c3e2c , < 63b53198aff2e4e6c5866a4ff73c7891f958ffa4 (git) Affected: 97a32539b9568bb653683349e5a76d02ff3c3e2c , < ede3e8ac90ae106f0b29cd759aadebc1568f1308 (git) Affected: 97a32539b9568bb653683349e5a76d02ff3c3e2c , < 64dc7c68e040251d9ec6e989acb69f8f6ae4a10b (git) Affected: 97a32539b9568bb653683349e5a76d02ff3c3e2c , < 654b33ada4ab5e926cd9c570196fefa7bec7c1df (git) |
|
| Linux | Linux |
Affected:
5.6
Unaffected: 0 , < 5.6 (semver) Unaffected: 5.10.236 , ≤ 5.10.* (semver) Unaffected: 5.15.180 , ≤ 5.15.* (semver) Unaffected: 6.1.132 , ≤ 6.1.* (semver) Unaffected: 6.6.85 , ≤ 6.6.* (semver) Unaffected: 6.12.21 , ≤ 6.12.* (semver) Unaffected: 6.13.9 , ≤ 6.13.* (semver) Unaffected: 6.14 , ≤ * (original_commit_for_fix) |
|
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
|
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
|
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP |
Affected:
V3.1.6 , < *
(custom)
|
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"timestamp": "2025-04-03T15:26:31.372538Z",
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"type": "CWE"
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"providerMetadata": {
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"url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html"
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{
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"product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP",
"vendor": "Siemens",
"versions": [
{
"lessThan": "*",
"status": "affected",
"version": "V3.1.6",
"versionType": "custom"
}
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}
],
"providerMetadata": {
"dateUpdated": "2026-09-08T08:41:04.317Z",
"orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"shortName": "siemens-SADP"
},
"references": [
{
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
}
],
"x_adpType": "supplier"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"fs/proc/generic.c",
"fs/proc/inode.c",
"fs/proc/internal.h",
"include/linux/proc_fs.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "eda279586e571b05dff44d48e05f8977ad05855d",
"status": "affected",
"version": "97a32539b9568bb653683349e5a76d02ff3c3e2c",
"versionType": "git"
},
{
"lessThan": "4b0b8445b6fd41e6f62ac90547a0ea9d348de3fa",
"status": "affected",
"version": "97a32539b9568bb653683349e5a76d02ff3c3e2c",
"versionType": "git"
},
{
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"status": "affected",
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"versionType": "git"
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{
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{
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},
{
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"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.6"
},
{
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"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "5.10.236",
"versionType": "semver"
},
{
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"status": "unaffected",
"version": "5.15.180",
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},
{
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"status": "unaffected",
"version": "6.1.132",
"versionType": "semver"
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"status": "unaffected",
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"version": "6.13.9",
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},
{
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}
]
}
],
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"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nproc: fix UAF in proc_get_inode()\n\nFix race between rmmod and /proc/XXX\u0027s inode instantiation.\n\nThe bug is that pde-\u003eproc_ops don\u0027t belong to /proc, it belongs to a\nmodule, therefore dereferencing it after /proc entry has been registered\nis a bug unless use_pde/unuse_pde() pair has been used.\n\nuse_pde/unuse_pde can be avoided (2 atomic ops!) because pde-\u003eproc_ops\nnever changes so information necessary for inode instantiation can be\nsaved _before_ proc_register() in PDE itself and used later, avoiding\npde-\u003eproc_ops-\u003e... dereference.\n\n rmmod lookup\nsys_delete_module\n proc_lookup_de\n\t\t\t pde_get(de);\n\t\t\t proc_get_inode(dir-\u003ei_sb, de);\n mod-\u003eexit()\n proc_remove\n remove_proc_subtree\n proc_entry_rundown(de);\n free_module(mod);\n\n if (S_ISREG(inode-\u003ei_mode))\n\t if (de-\u003eproc_ops-\u003eproc_read_iter)\n --\u003e As module is already freed, will trigger UAF\n\nBUG: unable to handle page fault for address: fffffbfff80a702b\nPGD 817fc4067 P4D 817fc4067 PUD 817fc0067 PMD 102ef4067 PTE 0\nOops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI\nCPU: 26 UID: 0 PID: 2667 Comm: ls Tainted: G\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996)\nRIP: 0010:proc_get_inode+0x302/0x6e0\nRSP: 0018:ffff88811c837998 EFLAGS: 00010a06\nRAX: dffffc0000000000 RBX: ffffffffc0538140 RCX: 0000000000000007\nRDX: 1ffffffff80a702b RSI: 0000000000000001 RDI: ffffffffc0538158\nRBP: ffff8881299a6000 R08: 0000000067bbe1e5 R09: 1ffff11023906f20\nR10: ffffffffb560ca07 R11: ffffffffb2b43a58 R12: ffff888105bb78f0\nR13: ffff888100518048 R14: ffff8881299a6004 R15: 0000000000000001\nFS: 00007f95b9686840(0000) GS:ffff8883af100000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: fffffbfff80a702b CR3: 0000000117dd2000 CR4: 00000000000006f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n \u003cTASK\u003e\n proc_lookup_de+0x11f/0x2e0\n __lookup_slow+0x188/0x350\n walk_component+0x2ab/0x4f0\n path_lookupat+0x120/0x660\n filename_lookup+0x1ce/0x560\n vfs_statx+0xac/0x150\n __do_sys_newstat+0x96/0x110\n do_syscall_64+0x5f/0x170\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\n[adobriyan@gmail.com: don\u0027t do 2 atomic ops on the common path]"
}
],
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"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
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{
"lang": "en",
"value": "AV:L - The vulnerable path is reached through ordinary local syscalls (stat/open/newstat) on paths under /proc, as shown by the commit\u0027s own trace from `ls` via `__do_sys_newstat` \u2192 `path_lookupat` \u2192 `proc_lookup_de` \u2192 `proc_get_inode`. No network protocol handling is involved.\nAC:L - The attacker fully controls their side of the race and can hold the window open continuously \u2014 `/proc/net` entries use `proc_net_dentry_ops` whose `.d_revalidate` always returns 0, so every single access re-runs `proc_lookup_de()`/`proc_get_inode()`, and fresh procfs mounts or netns via `unshare -Ur` defeat any dcache caching. On the realistic deployment targets (Android, embedded, automotive) module load/unload cycles are frequent and user-inducible via device/radio state changes, so no condition requires attacker-unattainable luck.\nPR:L - Triggering the vulnerable dereference requires only the ability to look up a path under /proc, which is mode 0555 and open to any unprivileged local user; no capability is checked anywhere on the lookup path. Unprivileged users can additionally use user namespaces to obtain fresh procfs/netns instances and to autoload modules that register `/proc/net` entries.\nUI:N - The attacker\u0027s exploitation loop is entirely self-driven \u2014 a continuous stat() loop on the target /proc entry \u2014 and requires no victim to open a file, mount a filesystem, or otherwise participate.\nS:U - The use-after-free occurs in kernel memory and its consequences are confined to the kernel\u0027s own security authority; there is no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - This is a use-after-free on freed module memory; once the vmalloc/execmem region is reclaimed and re-populated (e.g. by a subsequent module load), the stale read feeds attacker-influenceable data into inode setup, and UAF primitives of this class are leveraged for kernel memory disclosure.\nI:H - The UAF causes the kernel to select `i_fop` based on freed, potentially reallocated memory, yielding a stale-object/type-confusion condition on the instantiated inode; use-after-free on kernel structures is exploitable via heap grooming for control-flow-relevant corruption.\nA:H - The commit documents an unrecoverable oops \u2014 \"BUG: unable to handle page fault for address: fffffbfff80a702b \u2026 Oops: 0000 [#1] PREEMPT SMP KASAN PTI\" at `proc_get_inode+0x302` \u2014 and the attacker can retrigger it at will with a stat() loop, causing kernel crash/denial of service."
}
]
}
],
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"dateUpdated": "2026-09-08T08:41:04.317Z",
"state": "PUBLISHED"
},
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}
Loading…
Trend slope:
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(linear fit over daily sighting counts)
Show additional events:
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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