CVE-2025-22053
Medium · 5.5CVSS
5.5
EPSS
0.2%
Published
Apr 16, 2025
CISA due date
—
Cloudanix analysis
A flaw in certain IBM virtual network drivers can cause the system to freeze when multiple programs try to change network settings at the same time.
- Exploitation
- Local Privilege
- Attacker needs
- Local User
- Complexity
- Low
- Impact
- Denial Of Service
- Component
- OS kernel
- Class
- Race Condition
- Remediation
- Upgrade
- Effort
- Medium
- Patch risk
- Low
What it actually does
Race condition in ibmveth veth_pool_store allows concurrent sysfs writes to trigger repeated napi_disable calls without synchronization, causing permanent task hangs on mutex acquisition during napi_enable in ibmveth_open.
Why it matters to the business
Administrators performing pool configuration on affected IBM virtual Ethernet devices can trigger kernel task hangs that render the interface unusable and require reboots, disrupting network-dependent workloads on those systems.
How an attack unfolds
An attacker with local write access to the relevant /sys/devices/vio/.../pool* sysfs files runs concurrent writes (via shell script or similar) to veth_pool_store; the lack of rtnl_mutex protection allows overlapping calls that each invoke napi_disable, after which subsequent open attempts block indefinitely on the held lock.
How to fix it
Apply the upstream fix commit 1e458c292f4c687dcf5aad32dd4836d03cd2191f or later; rebuild and boot the patched kernel. Where distribution packages are available, upgrade ibmveth-containing kernel packages to a version containing this commit. Until patched, avoid concurrent writes to the pool sysfs attributes.
How to confirm the fix worked
Confirm the running kernel contains commit 1e458c292f4c687dcf5aad32dd4836d03cd2191f via 'uname -a' or kernel build info; re-run concurrent sysfs write tests and verify that veth_pool_store no longer blocks indefinitely and that lockdep reports no new warnings.
Typical attack path
- Obtain local shell or script execution on a system using the ibmveth driver
- Identify the sysfs paths under /sys/devices/vio/*/pool*
- Issue multiple rapid writes to active or pool files from separate processes
- Observe repeated 'close starting' messages followed by task hang on napi_enable mutex
- System experiences hung-task watchdog reports and potential loss of the network interface
How to detect it
Search kernel logs and systemd-journal for repeated 'ibmveth .* close starting' messages from different PIDs, followed by 'INFO: task .* blocked for more than .* seconds' and stack traces showing __mutex_lock inside napi_enable or ibmveth_open; inspect for concurrent sysfs writes to pool* files.
- ibmveth .* close starting
- napi_enable.*ibmveth_open
- veth_pool_store.*mutex_lock
- task blocked for more than .* seconds.*ibmveth
What your security team should do
- Prioritize patching kernel packages on all systems exposing ibmveth interfaces within the next maintenance window
- Add monitoring for hung-task messages containing ibmveth or napi_enable in system logs
- Restrict unprivileged write access to /sys/devices/vio/*/pool* paths via SELinux or file permissions where feasible
- Document the fixed commit hash for future kernel version validation
The record
In the Linux kernel, the following vulnerability has been resolved: net: ibmveth: make veth_pool_store stop hanging v2: - Created a single error handling unlock and exit in veth_pool_store - Greatly expanded commit message with previous explanatory-only text Summary: Use rtnl_mutex to synchronize veth_pool_store with itself, ibmveth_close and ibmveth_open, preventing multiple calls in a row to napi_disable. Background: Two (or more) threads could call veth_pool_store through writing to /sys/devices/vio/30000002/pool*/*. You can do this easily with a little shell script. This causes a hang. I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new kernel. I ran this test again and saw: Setting pool0/active to 0 Setting pool1/active to 1 [ 73.911067][ T4365] ibmveth 30000002 eth0: close starting Setting pool1/active to 1 Setting pool1/active to 0 [ 73.911367][ T4366] ibmveth 30000002 eth0: close starting [ 73.916056][ T4365] ibmveth 30000002 eth0: close complete [ 73.916064][ T4365] ibmveth 30000002 eth0: open starting [ 110.808564][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification. [ 230.808495][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification. [ 243.683786][ T123] INFO: task stress.sh:4365 blocked for more than 122 seconds. [ 243.683827][ T123] Not tainted 6.14.0-01103-g2df0c02dab82-dirty #8 [ 243.683833][ T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 243.683838][ T123] task:stress.sh state:D stack:28096 pid:4365 tgid:4365 ppid:4364 task_flags:0x400040 flags:0x00042000 [ 243.683852][ T123] Call Trace: [ 243.683857][ T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable) [ 243.683868][ T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0 [ 243.683878][ T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0 [ 243.683888][ T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210 [ 243.683896][ T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50 [ 243.683904][ T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0 [ 243.683913][ T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60 [ 243.683921][ T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc [ 243.683928][ T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270 [ 243.683936][ T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0 [ 243.683944][ T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0 [ 243.683951][ T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650 [ 243.683958][ T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150 [ 243.683966][ T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340 [ 243.683973][ T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec ... [ 243.684087][ T123] Showing all locks held in the system: [ 243.684095][ T123] 1 lock held by khungtaskd/123: [ 243.684099][ T123] #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248 [ 243.684114][ T123] 4 locks held by stress.sh/4365: [ 243.684119][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150 [ 243.684132][ T123] #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0 [ 243.684143][ T123] #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0 [ 243.684155][ T123] #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60 [ 243.684166][ T123] 5 locks held by stress.sh/4366: [ 243.684170][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150 [ 243. ---truncated---
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| Debian:11 | linux | 0 | No fix |
| Debian:12 | linux | 0 | No fix |
| Debian:13 | linux | 0 | No fix |
| Debian:13 | linux | 0 | 6.12.25-1 |
| Linux | Kernel | 2.6.18 | 6.6.87 |
| Mageia:9 | kernel | 0 | 6.6.88-3.mga9 |
| Mageia:9 | kernel-linus | 0 | 6.6.88-1.mga9 |
| Mageia:9 | kmod-virtualbox | 0 | 7.0.24-70.mga9 |
| Mageia:9 | kmod-xtables-addons | 0 | 3.24-78.mga9 |
| SUSE:Linux Enterprise High Availability Extension 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise High Availability Extension 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kernel-default | 0 | 4.12.14-122.258.1 |
| SUSE:Linux Enterprise Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_68 | 0 | 1-8.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_11 | 0 | 1-150600.1.3.2 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_11 | 0 | 1-150600.13.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_1 | 0 | 1-150700.15.3.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-64kb | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-default-base | 0 | 6.4.0-150600.23.50.1.150600.12.22.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-zfcpdump | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-64kb | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-default-base | 0 | 6.4.0-150700.53.3.1.150700.17.2.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-source | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP7 | kernel-zfcpdump | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 | kernel-coco | 0 | 6.4.0-15061.21.coco15sp6.1 |
| SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 | kernel-coco_debug | 0 | 6.4.0-15061.21.coco15sp6.1 |
| SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 | kernel-source-coco | 0 | 6.4.0-15061.21.coco15sp6.1 |
| SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 | kernel-syms-coco | 0 | 6.4.0-15061.21.coco15sp6.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP6 | kernel-docs | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP6 | kernel-obs-build | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP6 | kernel-source | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP6 | kernel-syms | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP7 | kernel-docs | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP7 | kernel-obs-build | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP7 | kernel-source | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Development Tools 15 SP7 | kernel-syms | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Legacy 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Module for Legacy 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | kernel-azure | 0 | 6.4.0-150600.8.37.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | kernel-source-azure | 0 | 6.4.0-150600.8.37.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | kernel-syms-azure | 0 | 6.4.0-150600.8.37.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP7 | kernel-azure | 0 | 6.4.0-150700.20.3.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP7 | kernel-source-azure | 0 | 6.4.0-150700.20.3.1 |
| SUSE:Linux Enterprise Module for Public Cloud 15 SP7 | kernel-syms-azure | 0 | 6.4.0-150700.20.3.1 |
| SUSE:Linux Enterprise Server 12 SP5-LTSS | kernel-default | 0 | 4.12.14-122.258.1 |
| SUSE:Linux Enterprise Server 12 SP5-LTSS | kernel-source | 0 | 4.12.14-122.258.1 |
| SUSE:Linux Enterprise Server 12 SP5-LTSS | kernel-syms | 0 | 4.12.14-122.258.1 |
| SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-default | 0 | 4.12.14-122.258.1 |
| SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-source | 0 | 4.12.14-122.258.1 |
| SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-syms | 0 | 4.12.14-122.258.1 |
| SUSE:Linux Enterprise Workstation Extension 15 SP6 | kernel-default | 0 | 6.4.0-150600.23.50.1 |
| SUSE:Linux Enterprise Workstation Extension 15 SP7 | kernel-default | 0 | 6.4.0-150700.53.3.1 |
| SUSE:Real Time Module 15 SP6 | kernel-rt | 0 | 6.4.0-150600.10.39.1 |
| SUSE:Real Time Module 15 SP6 | kernel-rt_debug | 0 | 6.4.0-150600.10.39.1 |
| SUSE:Real Time Module 15 SP6 | kernel-source-rt | 0 | 6.4.0-150600.10.39.1 |
| SUSE:Real Time Module 15 SP6 | kernel-syms-rt | 0 | 6.4.0-150600.10.39.1 |
| openSUSE:Leap 15.6 | dtb-aarch64 | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-64kb | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-azure | 0 | 6.4.0-150600.8.37.1 |
| openSUSE:Leap 15.6 | kernel-debug | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-default | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-default-base | 0 | 6.4.0-150600.23.50.1.150600.12.22.1 |
| openSUSE:Leap 15.6 | kernel-docs | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-kvmsmall | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-obs-build | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-obs-qa | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-rt | 0 | 6.4.0-150600.10.39.1 |
| openSUSE:Leap 15.6 | kernel-rt_debug | 0 | 6.4.0-150600.10.39.1 |
| openSUSE:Leap 15.6 | kernel-source | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-source-azure | 0 | 6.4.0-150600.8.37.1 |
| openSUSE:Leap 15.6 | kernel-source-rt | 0 | 6.4.0-150600.10.39.1 |
| openSUSE:Leap 15.6 | kernel-syms | 0 | 6.4.0-150600.23.50.1 |
| openSUSE:Leap 15.6 | kernel-syms-azure | 0 | 6.4.0-150600.8.37.1 |
| openSUSE:Leap 15.6 | kernel-syms-rt | 0 | 6.4.0-150600.10.39.1 |
| openSUSE:Leap 15.6 | kernel-zfcpdump | 0 | 6.4.0-150600.23.50.1 |
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