Linux Kernel up to 7.3.0 keys search_process_keyrings_rcu null pointer dereference

CVSS Meta Temp Score
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6.0$0-$5k2.12-

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 7.3.0. The impacted element is the function search_process_keyrings_rcu of the component keys. Such manipulation leads to null pointer dereference. This vulnerability is referenced as CVE-2026-99225. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.3.0. It has been rated as critical. Affected by this issue is the function search_process_keyrings_rcu of the component keys. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: keys: Check the authorization payload in process keyring searches An authorization payload and its saved credentials must remain valid while search_process_keyrings_rcu() searches the requestor's keyrings. The function validates the authorization key, then separately loads payload.data[0] and unconditionally reads rka->cred. Validation does not prevent request_key_auth_revoke() from clearing the payload. A request-key helper can assume authority and fork a descendant that inherits the authorization key. If the descendant misses in its own keyrings, it falls back to the saved requestor credentials. Successful target instantiation invalidates the authorization key without clearing the payload. After the helper exits, UMH_WAIT_PROC returns to the requester, which calls complete_request_key() and revokes that key. With the descendant paused after validation, the paths can interleave as follows: 1. The descendant enters search_process_keyrings_rcu() under RCU and key_validate() succeeds. 2. The helper instantiates the target, invalidates the authorization key, and exits. 3. The requester resumes from UMH_WAIT_PROC, calls complete_request_key(), and revokes the authorization key. request_key_auth_revoke() sets its payload pointer to NULL. 4. The descendant loads NULL and dereferences rka->cred. This NULL dereference can oops the kernel. RCU delays payload disposal but does not prevent the pointer from being cleared. Load the payload with dereference_key_rcu() and require a non-NULL result before validating the authorization key and searching its saved credentials. A non-NULL payload and its credentials remain alive for the caller's RCU read-side section; a cleared payload skips the fallback search and follows the existing error selection. KASAN report as below: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] RIP: 0010:search_process_keyrings_rcu+0x32b/0x790

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-99225 since 09/25/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 11/02/2026).

Upgrading to version 5.10.273, 5.15.224, 6.1.191, 6.6.161, 6.12.115, 6.18.60, 7.2.14 or 7.3.1 eliminates this vulnerability. Applying the patch 14fb6fad526b35a7ebd121f1dd313abe652e0aa6/458cf9715af6aff3ac8d2ec60bd59e9d6236fd0f/7d3d2fffe933e538472ccafe5bbc7109488b9ce3/26949c2e4c461e9e620e935bc22717f36a40b615/984a178d54515779a1bee100b92a6cee8777c830/b86db7993051d05810601654e886a1e78e1fa495/b4dfda438fee3c6faa15d9b421c373de6a0e476f/49f4e768540d25d8852ef750313afda6a4774871 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.273/5.15.224/6.1.191/6.6.161/6.12.115/6.18.60/7.2.14/7.3.1
Patch: 14fb6fad526b35a7ebd121f1dd313abe652e0aa6/458cf9715af6aff3ac8d2ec60bd59e9d6236fd0f/7d3d2fffe933e538472ccafe5bbc7109488b9ce3/26949c2e4c461e9e620e935bc22717f36a40b615/984a178d54515779a1bee100b92a6cee8777c830/b86db7993051d05810601654e886a1e78e1fa495/b4dfda438fee3c6faa15d9b421c373de6a0e476f/49f4e768540d25d8852ef750313afda6a4774871

Timelineinfo

09/25/2026 CVE reserved
11/02/2026 +38 days Advisory disclosed
11/02/2026 +0 days VulDB entry created
11/02/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CNA: Linux
CVE: CVE-2026-99225 (🔒)

GCVE (CVE): GCVE-0-2026-99225
GCVE (VulDB): GCVE-100-429920

Entryinfo

Created: 11/02/2026 17:28
Changes: 11/02/2026 17:28 (59)
Complete: 🔍
Cache ID: 216::103

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