Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:ALSA: seq: Serialize UMP output teardown with event_input
seq_ump_process_event() borrows client->out_rfile.output without
synchronizing with the first-open and last-close transition in
seq_ump_client_open() and seq_ump_client_close().
The last output unuse can therefore drop opened[STR_OUT] to zero and
release the rawmidi file while an in-flight event_input callback is still
inside snd_rawmidi_kernel_write(). That leaves the rawmidi substream
runtime exposed to teardown before the write path has taken its own
buffer reference.
Add a per-client rwlock for the event_input-visible output file. Publish
a newly opened output file under the write side, and hold the read side
from the output lookup through snd_rawmidi_kernel_write(). The last
output close copies and clears the visible output file under the write
side, then drops the lock and releases the saved rawmidi file. Use
IRQ-safe rwlock guards because event_input can also be reached from
atomic sequencer delivery.
The buggy scenario involves two paths, with each column showing the
order within that path:
path A label: event_input path path B label: last unuse path
1. seq_ump_process_event() reads 1. seq_ump_client_close()
client->out_rfile.output. drops opened[STR_OUT] to zero.
2. snd_rawmidi_kernel_write1() 2. snd_rawmidi_kernel_release()
has not yet pinned runtime. closes the output file.
3. The writer continues using 3. close_substream() frees
the borrowed substream. substream->runtime.
This keeps the output substream and runtime alive for the full
event_input write while keeping rawmidi release outside the rwlock.
KASAN reproduced this as a slab-use-after-free in
snd_rawmidi_kernel_write1(), with allocation through
seq_ump_use()/snd_seq_port_connect() and free through
seq_ump_unuse()/snd_seq_port_disconnect().
Validation reproduced this kernel report:
KASAN slab-use-after-free in snd_rawmidi_kernel_write1+0x9d/0x400
RIP: 0033:0x7f5528af837f
Read of size 8
Call trace:
dump_stack_lvl+0x73/0xb0 (?:?)
print_report+0xd1/0x650 (?:?)
srso_alias_return_thunk+0x5/0xfbef5 (?:?)
__virt_addr_valid+0x1a7/0x340 (?:?)
kasan_complete_mode_report_info+0x64/0x200 (?:?)
kasan_report+0xf7/0x130 (?:?)
snd_rawmidi_kernel_write1+0x9d/0x400 (?:?)
__asan_load8+0x82/0xb0 (?:?)
update_stack_state+0x1ef/0x2d0 (?:?)
snd_rawmidi_kernel_write+0x1a/0x20 (?:?)
seq_ump_process_event+0xd4/0x120 (sound/core/seq/seq_ump_client.c:82)
__snd_seq_deliver_single_event+0x8a/0xe0 (?:?)
snd_seq_deliver_from_ump+0x2b2/0xd60 (?:?)
lock_acquire+0x14e/0x2e0 (?:?)
find_held_lock+0x31/0x90 (?:?)
snd_seq_port_use_ptr+0xa6/0xe0 (?:?)
__kasan_check_write+0x18/0x20 (?:?)
do_raw_read_unlock+0x32/0xa0 (?:?)
_raw_read_unlock+0x26/0x50 (?:?)
snd_seq_deliver_single_event+0x45c/0x4b0 (?:?)
snd_seq_deliver_event+0x10d/0x1b0 (?:?)
snd_seq_client_enqueue_event+0x192/0x240 (?:?)
snd_seq_write+0x2cd/0x450 (?:?)
apparmor_file_permission+0x20/0x30 (?:?)
security_file_permission+0x51/0x60 (?:?)
vfs_write+0x1ce/0x850 (?:?)
__fget_files+0x12b/0x220 (?:?)
lock_release+0xc8/0x2a0 (?:?)
__rcu_read_unlock+0x74/0x2d0 (?:?)
__fget_files+0x135/0x220 (?:?)
ksys_write+0x15a/0x180 (?:?)
rcu_is_watching+0x24/0x60 (?:?)
__x64_sys_write+0x46/0x60 (?:?)
x64_sys_call+0x7d/0x20d0 (?:?)
do_syscall_64+0xc1/0x360 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)
SUSE information
Overall state of this security issue: New
This issue is currently rated as having important severity.
| CVSS detail | CNA (NVD) | Linux Kernel CNA |
|---|---|---|
| Base Score | 7.8 | 7.8 |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/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 | Local | Local |
| Attack Complexity | Low | Low |
| Privileges Required | Low | Low |
| User Interaction | None | None |
| Scope | Unchanged | Unchanged |
| Confidentiality Impact | High | High |
| Integrity Impact | High | High |
| Availability Impact | High | High |
| CVSSv3 Version | 3.1 | 3.1 |
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. No SUSE Bugzilla entries cross referenced. 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 | Analysis |
| SUSE Linux Enterprise Desktop 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise High Availability Extension 16.0 | kernel-default | Analysis |
| SUSE Linux Enterprise High Availability Extension 16.0 | kernel-source | Analysis |
| SUSE Linux Enterprise High Availability Extension 16.1 | kernel-default | Analysis |
| SUSE Linux Enterprise High Availability Extension 16.1 | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise Live Patching 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise Live Patching 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise Micro 5.3 | kernel-default | Analysis |
| SUSE Linux Enterprise Micro 5.3 | kernel-rt | Analysis |
| SUSE Linux Enterprise Micro 5.3 | kernel-source | Analysis |
| SUSE Linux Enterprise Micro 5.3 | kernel-source-rt | Analysis |
| SUSE Linux Enterprise Micro 5.4 | kernel-default | Analysis |
| SUSE Linux Enterprise Micro 5.4 | kernel-rt | Analysis |
| SUSE Linux Enterprise Micro 5.4 | kernel-source | Analysis |
| SUSE Linux Enterprise Micro 5.4 | kernel-source-rt | Analysis |
| SUSE Linux Enterprise Micro 5.5 | kernel-default | Analysis |
| SUSE Linux Enterprise Micro 5.5 | kernel-source | Analysis |
| SUSE Linux Enterprise Micro 5.5 | kernel-source-rt | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise Real Time 15 SP7 | kernel-source-rt | Analysis |
| SUSE Linux Enterprise Server 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise Server 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 16.0 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 16.1 | kernel-default | Analysis |
| SUSE Linux Enterprise Server 16.1 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-default | Analysis |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-source | Analysis |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | kernel-default | Analysis |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | kernel-source | Analysis |
| SUSE Linux Micro 6.0 | kernel-default | Analysis |
| SUSE Linux Micro 6.0 | kernel-source | Analysis |
| SUSE Linux Micro 6.0 | kernel-source-rt | Analysis |
| SUSE Linux Micro 6.1 | kernel-default | Analysis |
| SUSE Linux Micro 6.1 | kernel-source | Analysis |
| SUSE Linux Micro 6.1 | kernel-source-rt | Analysis |
| SUSE Linux Micro 6.2 | kernel-default | Analysis |
| SUSE Linux Micro 6.2 | kernel-source | Analysis |
| SUSE Linux Micro Extras 6.0 | kernel-default | Analysis |
| SUSE Linux Micro Extras 6.0 | kernel-source | Analysis |
| SUSE Linux Micro Extras 6.0 | kernel-source-rt | Analysis |
| SUSE Real Time Module 15 SP7 | kernel-source-rt | Analysis |
| openSUSE Leap 16.0 | kernel-source | Analysis |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 15 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Live Patching 12 SP5 | kernel-default | Analysis |
| SUSE Linux Enterprise Live Patching 12 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise Live Patching 15 SP4 | kernel-default | Analysis |
| SUSE Linux Enterprise Live Patching 15 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Live Patching 15 SP5 | kernel-default | Analysis |
| SUSE Linux Enterprise Live Patching 15 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-default | Analysis |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-source | Analysis |
| SUSE Linux Enterprise Server 12 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | kernel-default | Analysis |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP6 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-default | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-source | Analysis |
| SUSE Manager Proxy 4.3 | kernel-source | Analysis |
| SUSE Manager Proxy LTS 4.3 | kernel-source | Analysis |
| SUSE Manager Retail Branch Server 4.3 | kernel-source | Analysis |
| SUSE Manager Retail Branch Server LTS 4.3 | kernel-source | Analysis |
| SUSE Manager Server 4.3 | kernel-source | Analysis |
| SUSE Manager Server LTS 4.3 | kernel-source | Analysis |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE CaaS Platform 4.0 | kernel-source | Analysis |
| SUSE Enterprise Storage 6 | kernel-source | Analysis |
| SUSE Enterprise Storage 7 | kernel-source | Analysis |
| SUSE Enterprise Storage 7.1 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 11 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 15 SP2 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 15 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-source | Analysis |
| SUSE Linux Enterprise Desktop 15 SP6 | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-source | Analysis |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | kernel-source | Analysis |
| SUSE Linux Enterprise Micro 5.0 | kernel-default | Analysis |
| SUSE Linux Enterprise Micro 5.1 | kernel-default | Analysis |
| SUSE Linux Enterprise Micro 5.2 | kernel-default | Analysis |
| SUSE Linux Enterprise Micro 5.2 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | kernel-source | Analysis |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-source | Analysis |
| SUSE Linux Enterprise Real Time 15 SP2 | kernel-source | Analysis |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source | Analysis |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source-rt | Analysis |
| SUSE Linux Enterprise Real Time 15 SP5 | kernel-source-rt | Analysis |
| SUSE Linux Enterprise Server 11 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 11 SP4-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP1-BCL | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP2 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP2-BCL | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP3 | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP3-BCL | kernel-source | Analysis |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-default | Analysis |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-default | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-default | Analysis |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source | Analysis |
| SUSE Manager Proxy 4.0 | kernel-source | Analysis |
| SUSE Manager Proxy 4.1 | kernel-source | Analysis |
| SUSE Manager Proxy 4.2 | kernel-source | Analysis |
| SUSE Manager Retail Branch Server 4.0 | kernel-source | Analysis |
| SUSE Manager Retail Branch Server 4.1 | kernel-source | Analysis |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Analysis |
| SUSE Manager Server 4.0 | kernel-source | Analysis |
| SUSE Manager Server 4.1 | kernel-source | Analysis |
| SUSE Manager Server 4.2 | kernel-source | Analysis |
| SUSE Real Time Module 15 SP4 | kernel-source-rt | Analysis |
| SUSE Real Time Module 15 SP5 | kernel-source-rt | Analysis |
| openSUSE Leap 15.3 | kernel-source | Analysis |
| openSUSE Leap 15.4 | kernel-source | Analysis |
| openSUSE Leap 15.4 | kernel-source-rt | Analysis |
| openSUSE Leap 15.5 | kernel-source | Analysis |
| openSUSE Leap 15.5 | kernel-source-rt | Analysis |
| openSUSE Leap 15.6 | kernel-source | Analysis |
SUSE Timeline for this CVE
CVE page created: Mon Jul 20 11:53:00 2026CVE page last modified: Tue Jul 21 11:36:09 2026