nbd: don't allow reconnect after disconnect

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-21731
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-02-27 02:15:16 UTC
Updated2026-07-14 13:17:22 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: nbd: don't allow reconnect after disconnect Following process can cause nbd_config UAF: 1) grab nbd_config temporarily; 2) nbd_genl_disconnect() flush all recv_work() and release the initial reference: nbd_genl_disconnect nbd_disconnect_and_put nbd_disconnect flush_workqueue(nbd->recv_workq) if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...)) nbd_config_put -> due to step 1), reference is still not zero 3) nbd_genl_reconfigure() queue recv_work() again; nbd_genl_reconfigure config = nbd_get_config_unlocked(nbd) if (!config) -> succeed if (!test_bit(NBD_RT_BOUND, ...)) -> succeed nbd_reconnect_socket queue_work(nbd->recv_workq, &args->work) 4) step 1) release the reference; 5) Finially, recv_work() will trigger UAF: recv_work nbd_config_put(nbd) -> nbd_config is freed atomic_dec(&config->recv_threads) -> UAF Fix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so that nbd_genl_reconfigure() will fail.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from ADP

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Problem Types: CWE-416 | CWE-416 CWE-416 Use After Free

VersionSourceTypeScoreSeverityVector
3.1ADPDECLARED7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
3.1134c704f-9b21-4f2e-91b3-4a467353bcc0Secondary7.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected b7aa3d39385dc2d95899f9e379623fef446a2acd e70a578487a47d7cf058904141e586684d1c3381 git Not specified
CNA Linux Linux affected b7aa3d39385dc2d95899f9e379623fef446a2acd 6bef6222a3f6c7adb6396f77f25a3579d821b09a git Not specified
CNA Linux Linux affected b7aa3d39385dc2d95899f9e379623fef446a2acd e3be8862d73cac833e0fb7602636c19c6cb94b11 git Not specified
CNA Linux Linux affected b7aa3d39385dc2d95899f9e379623fef446a2acd e7343fa33751cb07c1c56b666bf37cfca357130e git Not specified
CNA Linux Linux affected b7aa3d39385dc2d95899f9e379623fef446a2acd d208d2c52b652913b5eefc8ca434b0d6b757f68f git Not specified
CNA Linux Linux affected b7aa3d39385dc2d95899f9e379623fef446a2acd a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739 git Not specified
CNA Linux Linux affected b7aa3d39385dc2d95899f9e379623fef446a2acd 9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302 git Not specified
CNA Linux Linux affected b7aa3d39385dc2d95899f9e379623fef446a2acd 844b8cdc681612ff24df62cdefddeab5772fadf1 git Not specified
CNA Linux Linux affected 4.12 Not specified
CNA Linux Linux unaffected 4.12 semver Not specified
CNA Linux Linux unaffected 5.4.291 5.4.* semver Not specified
CNA Linux Linux unaffected 5.10.235 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.179 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.129 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.76 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.13 6.12.* semver Not specified
CNA Linux Linux unaffected 6.13.2 6.13.* semver Not specified
CNA Linux Linux unaffected 6.14 * original_commit_for_fix Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.6 * custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.6 * custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP affected V3.1.6 * custom Not specified
ADP Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP affected V3.1.6 * custom Not specified
ADP Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP affected V3.1.6 * custom Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/e7343fa33751cb07c1c56b666bf37cfca357130e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2025/05/msg00030.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
git.kernel.org/stable/c/a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/6bef6222a3f6c7adb6396f77f25a3579d821b09a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/e70a578487a47d7cf058904141e586684d1c3381 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/844b8cdc681612ff24df62cdefddeab5772fadf1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
cert-portal.siemens.com/productcert/html/ssa-019113.html 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e cert-portal.siemens.com
git.kernel.org/stable/c/e3be8862d73cac833e0fb7602636c19c6cb94b11 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/d208d2c52b652913b5eefc8ca434b0d6b757f68f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
lists.debian.org/debian-lts-announce/2025/03/msg00028.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org
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