Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:ksmbd: fix use-after-free of conn->preauth_info in concurrent SMB2 NEGOTIATE
conn->preauth_info is shared connection state (struct
preauth_integrity_info, kmalloc-96) that is allocated and freed by the
SMB2 NEGOTIATE handler and read by the response send path.
smb2_handle_negotiate() allocates conn->preauth_info, and on a
deassemble_neg_contexts() failure kfrees it and sets it to NULL. Both the
allocation and the free/NULL happen under ksmbd_conn_lock(conn) (the
connection srv_mutex), which is held across the whole handler body.
The response send path smb3_preauth_hash_rsp(), called from the send:
block of __handle_ksmbd_work(), reads conn->preauth_info and dereferences
conn->preauth_info->Preauth_HashValue (via
ksmbd_gen_preauth_integrity_hash()) without taking conn_lock. When a
client drives two SMB2 NEGOTIATE requests on the same connection, one
worker can free conn->preauth_info on the failing-negotiate path while a
concurrent send-path worker is reading it, producing a slab
use-after-free read (KASAN-confirmed).
The send-path read tested conn->preauth_info for NULL but raced with the
free that occurs between the NULL check and the dereference, so the NULL
guard alone does not close the window.
Serialize the NEGOTIATE-branch read in smb3_preauth_hash_rsp() under
ksmbd_conn_lock(conn) and re-check conn->preauth_info inside the lock.
Because the negotiate handler holds conn_lock across its kfree + NULL
assignment, a reader that also takes conn_lock either runs fully before
the allocation or fully after the NULL store, and can never observe the
freed-but-not-yet-NULLed pointer. ksmbd_gen_preauth_integrity_hash()
takes no locks itself (it only computes a SHA-512 over the buffer), so
no lock-ordering inversion is introduced, and conn_lock is a sleepable
mutex which is safe on this send path (it already performs network I/O).
SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having important severity.
| CVSS detail | CNA (NVD) | Linux Kernel CNA | SUSE |
|---|---|---|---|
| Base Score | 9.8 | 9.8 | 7.8 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| Attack Vector | Network | Network | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | None | None | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality Impact | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | High | High | High |
| CVSSv3 Version | 3.1 | 3.1 | 3.1 |
| CVSS detail | SUSE |
|---|---|
| Base Score | 8.5 |
| Vector | CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| Attack Vector | Local |
| Attack Complexity | Low |
| Attack Requirements | None |
| Privileges Required | Low |
| User Interaction | None |
| Vulnerable System Confidentiality Impact | High |
| Vulnerable System Integrity Impact | High |
| Vulnerable System Availability Impact | High |
| Subsequent System Confidentiality Impact | None |
| Subsequent System Integrity Impact | None |
| Subsequent System Availability Impact | None |
| CVSSv4 Version | 4.0 |
Note from the SUSE Security Team on the kernel-default package
SUSE will no longer fix all CVEs in the Linux Kernel anymore, but declare some bug classes as won't fix. Please refer to TID 21496 for more details. SUSE Bugzilla entries: 1277042 [NEW], 1277043 [NEW] No SUSE Security Announcements cross referenced.Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Linux Enterprise Desktop 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise Desktop 15 SP7 | kernel-source | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-source | Affected |
| SUSE Linux Enterprise High Availability Extension 16.0 | kernel-default | Affected |
| SUSE Linux Enterprise High Availability Extension 16.0 | kernel-source | Affected |
| SUSE Linux Enterprise High Availability Extension 16.1 | kernel-default | Affected |
| SUSE Linux Enterprise High Availability Extension 16.1 | kernel-source | Affected |
| SUSE Linux Enterprise Live Patching 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise Live Patching 15 SP7 | kernel-source | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-rt | Not affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-rt | Not affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP7 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Server 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP7 | kernel-source | Affected |
| SUSE Linux Enterprise Server 16.0 | kernel-default | Affected |
| SUSE Linux Enterprise Server 16.0 | kernel-source | Affected |
| SUSE Linux Enterprise Server 16.1 | kernel-default | Affected |
| SUSE Linux Enterprise Server 16.1 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-source | Affected |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | kernel-default | Affected |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | kernel-source | Affected |
| SUSE Linux Micro 6.0 | kernel-default | Affected |
| SUSE Linux Micro 6.0 | kernel-source | Affected |
| SUSE Linux Micro 6.0 | kernel-source-rt | Affected |
| SUSE Linux Micro 6.1 | kernel-default | Affected |
| SUSE Linux Micro 6.1 | kernel-source | Affected |
| SUSE Linux Micro 6.1 | kernel-source-rt | Affected |
| SUSE Linux Micro 6.2 | kernel-default | Affected |
| SUSE Linux Micro 6.2 | kernel-source | Affected |
| SUSE Linux Micro Extras 6.0 | kernel-default | Affected |
| SUSE Linux Micro Extras 6.0 | kernel-source | Affected |
| SUSE Linux Micro Extras 6.0 | kernel-source-rt | Affected |
| SUSE Linux Micro Extras 6.1 | kernel-default | Affected |
| SUSE Linux Micro Extras 6.1 | kernel-source | Affected |
| SUSE Real Time Module 15 SP7 | kernel-source-rt | Affected |
| openSUSE Leap 16.0 | kernel-source | Affected |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-default | Not affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-default | Not affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-source | Affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE CaaS Platform 4.0 | kernel-source | Not affected |
| SUSE Enterprise Storage 6 | kernel-source | Not affected |
| SUSE Enterprise Storage 7 | kernel-source | Not affected |
| SUSE Enterprise Storage 7.1 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.0 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.1 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Real Time 15 SP5 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Server 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 11 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-source | Not affected |
| SUSE Manager Proxy 4.0 | kernel-source | Not affected |
| SUSE Manager Proxy 4.1 | kernel-source | Not affected |
| SUSE Manager Proxy 4.2 | kernel-source | Not affected |
| SUSE Manager Proxy 4.3 | kernel-source | Not affected |
| SUSE Manager Proxy LTS 4.3 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.0 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.1 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.3 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server LTS 4.3 | kernel-source | Not affected |
| SUSE Manager Server 4.0 | kernel-source | Not affected |
| SUSE Manager Server 4.1 | kernel-source | Not affected |
| SUSE Manager Server 4.2 | kernel-source | Not affected |
| SUSE Manager Server 4.3 | kernel-source | Not affected |
| SUSE Manager Server LTS 4.3 | kernel-source | Not affected |
| SUSE Real Time Module 15 SP4 | kernel-source-rt | Not affected |
| SUSE Real Time Module 15 SP5 | kernel-source-rt | Not affected |
| openSUSE Leap 15.3 | kernel-source | Not affected |
| openSUSE Leap 15.4 | kernel-source | Not affected |
| openSUSE Leap 15.4 | kernel-source-rt | Not affected |
| openSUSE Leap 15.5 | kernel-source | Not affected |
| openSUSE Leap 15.5 | kernel-source-rt | Not affected |
| openSUSE Leap 15.6 | kernel-source | Affected |
SUSE Timeline for this CVE
CVE page created: Thu Aug 27 14:09:51 2026CVE page last modified: Wed Sep 2 12:16:40 2026