Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:ipv4: free inet_opt and ireq_opt after an RCU grace period
tcp_v4_syn_recv_sock() transfers ownership of ireq->ireq_opt to the
child socket (newinet->inet_opt) without copying it.
Another cpu can concurrently process a retransmitted SYN for the same
request socket, and send a SYNACK from tcp_check_req().
tcp_v4_send_synack() and inet_csk_route_req() read ireq->ireq_opt
under rcu_read_lock() only, and ip_build_and_send_pkt() and
ip_options_build() then read opt->optlen twice.
Note that the SYNACK timer itself is not an issue: it holds a
reference on its request socket, and inet_csk_reqsk_queue_drop()
calls timer_delete_sync() before the child can be freed.
Since commit 079096f103fa ("tcp/dccp: install syn_recv requests
into ehash table"), request sockets are processed without holding
the listener lock, so nothing prevents the child socket from being
freed while the SYNACK is still being built. TCP child sockets do
not have SOCK_RCU_FREE, and inet_sock_destruct() frees inet_opt
with a plain kfree(), leading to a use-after-free in
ip_options_build().
A similar issue exists with request socket migration
(net.ipv4.tcp_migrate_req=1, or a BPF_SK_REUSEPORT_SELECT_OR_MIGRATE
program). reqsk_timer_handler() clones the request socket with
inet_reqsk_clone(), so that the old request socket and its clone
share the same ireq_opt, then reqsk_migrate_reset() clears the
pointer in the old one. Another cpu holding a reference on the old
request socket can still be using these options (sending a SYNACK,
or creating a child in tcp_v4_syn_recv_sock()) when the clone is
freed, and tcp_v4_reqsk_destructor() also uses a plain kfree().
Readers already use RCU, and other paths replacing inet_opt
(do_ip_setsockopt(), cipso_v4_sock_setattr()...) already use
kfree_rcu(). Use kfree_rcu() in inet_sock_destruct() and
tcp_v4_reqsk_destructor() as well.
IPv6 is not affected by the first issue, because tcp_v6_syn_recv_sock()
duplicates the options. tcp_v6_reqsk_destructor() has the same
migration issue with ipv6_opt, which is only set by CALIPSO. This
will be addressed in a separate patch.
SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having important severity.
| CVSS detail | SUSE |
|---|---|
| Base Score | 8.1 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | High |
| Integrity Impact | High |
| Availability Impact | High |
| CVSSv3 Version | 3.1 |
| CVSS detail | SUSE |
|---|---|
| Base Score | 9.2 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| Attack Vector | Network |
| Attack Complexity | Low |
| Attack Requirements | Present |
| Privileges Required | None |
| 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 entry: 1285685 [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 Micro 5.3 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-rt | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-source | Affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-rt | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-source | Affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-source | Affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-source-rt | 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 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 16.2 | kernel-source | Affected |
| SUSE Linux Enterprise Server for NVIDIA 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 Server for SAP applications 16.2 | 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 |
| openSUSE Leap 16.1 | 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 | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-source | 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 | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-source | 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 | Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-default | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source | 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 | Affected |
| SUSE Enterprise Storage 6 | kernel-source | Affected |
| SUSE Enterprise Storage 7 | kernel-source | Affected |
| SUSE Enterprise Storage 7.1 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-source | Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-source | Affected |
| SUSE Linux Enterprise Micro 5.0 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.1 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-default | Affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source-rt | Affected |
| SUSE Linux Enterprise Real Time 15 SP5 | kernel-source-rt | 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 | Affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP3 | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | kernel-source | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-default | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | kernel-source | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-source | Affected |
| SUSE Manager Proxy 4.0 | kernel-source | Affected |
| SUSE Manager Proxy 4.1 | kernel-source | Affected |
| SUSE Manager Proxy 4.2 | kernel-source | Affected |
| SUSE Manager Proxy 4.3 | kernel-source | Affected |
| SUSE Manager Proxy LTS 4.3 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.0 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.1 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Affected |
| SUSE Manager Retail Branch Server 4.3 | kernel-source | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | kernel-source | Affected |
| SUSE Manager Server 4.0 | kernel-source | Affected |
| SUSE Manager Server 4.1 | kernel-source | Affected |
| SUSE Manager Server 4.2 | kernel-source | Affected |
| SUSE Manager Server 4.3 | kernel-source | Affected |
| SUSE Manager Server LTS 4.3 | kernel-source | Affected |
| SUSE Real Time Module 15 SP4 | kernel-source-rt | Affected |
| SUSE Real Time Module 15 SP5 | kernel-source-rt | Affected |
| openSUSE Leap 15.3 | kernel-source | Affected |
| openSUSE Leap 15.4 | kernel-source | Affected |
| openSUSE Leap 15.4 | kernel-source-rt | Affected |
| openSUSE Leap 15.5 | kernel-source | Affected |
| openSUSE Leap 15.5 | kernel-source-rt | Affected |
| openSUSE Leap 15.6 | kernel-source | Affected |
SUSE Timeline for this CVE
CVE page created: Thu Oct 15 22:39:15 2026CVE page last modified: Thu Oct 15 22:39:15 2026