Cloudanix VulnDB

CVE-2025-22089

None

CVSS

—

EPSS

0.2%

Published

Apr 16, 2025

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A bug in the Linux kernel can make certain hardware statistics visible inside isolated network containers, and trying to read those statistics crashes the whole machine.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Low
Impact
Denial Of Service
Component
OS kernel
Class
Memory Corruption
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Exposure of RDMA hardware counter sysfs attributes into non-init network namespaces combined with incorrect container_of casting in hw_stat_device_show leads to NULL pointer dereference on read access and kernel panic.

Why it matters to the business

Systems using RDMA in containers or network namespaces can experience sudden kernel crashes and reboots when users or processes attempt to read hardware statistics, interrupting workloads and requiring restarts.

How an attack unfolds

An attacker with local access creates a new network namespace, enters it, and reads any file under the exposed hw_counters sysfs path for an RDMA device; the kernel performs an invalid pointer cast and dereferences NULL, triggering a panic. No remote code execution or privilege escalation occurs.

How to fix it

Apply the upstream fix that zeros the hw_counters attribute group pointer for non-init namespaces during RDMA device initialization; update to a kernel containing commit 9a5b7f8842a90a5e6eeff37f9f6d814e61ea3529 or later equivalent stable backport.

How to confirm the fix worked

After patching, verify that hw_counters directories are absent when viewed from a non-init network namespace while remaining present in the init namespace; confirm no NULL dereference occurs on attempted reads.

Typical attack path

  1. Create non-init network namespace with ip netns add
  2. Enter the namespace and locate RDMA device hw_counters entries under /sys/class/infiniband
  3. Read any file in the hw_counters directory
  4. Kernel executes hw_stat_device_show with corrupted device pointer
  5. NULL dereference causes BUG and system panic

How to detect it

Search kernel logs and crash dumps for the signature of hw_stat_device_show NULL dereference and page faults at address 0x28; inspect audit or sysfs access logs for reads of hw_counters paths originating from non-init network namespace PIDs.

  • BUG: kernel NULL pointer dereference.*hw_stat_device_show
  • RIP:.*hw_stat_device_show+0x1e/0x40
  • /sys/class/infiniband/*/hw_counters
  • ip netns exec.*cat.*hw_counters

What your security team should do

  • Prioritize kernel updates on any host exposing RDMA devices to untrusted namespaces or containers
  • Audit workloads that create network namespaces and use RDMA hardware
  • Monitor for kernel oops involving hw_stat_device_show or ib_core in crash dumps
  • Restrict unprivileged namespace creation via kernel.unprivileged_userns_clone where feasible

The record

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Don't expose hw_counters outside of init net namespace Commit 467f432a521a ("RDMA/core: Split port and device counter sysfs attributes") accidentally almost exposed hw counters to non-init net namespaces. It didn't expose them fully, as an attempt to read any of those counters leads to a crash like this one: [42021.807566] BUG: kernel NULL pointer dereference, address: 0000000000000028 [42021.814463] #PF: supervisor read access in kernel mode [42021.819549] #PF: error_code(0x0000) - not-present page [42021.824636] PGD 0 P4D 0 [42021.827145] Oops: 0000 [#1] SMP PTI [42021.830598] CPU: 82 PID: 2843922 Comm: switchto-defaul Kdump: loaded Tainted: G S W I XXX [42021.841697] Hardware name: XXX [42021.849619] RIP: 0010:hw_stat_device_show+0x1e/0x40 [ib_core] [42021.855362] Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 49 89 d0 4c 8b 5e 20 48 8b 8f b8 04 00 00 48 81 c7 f0 fa ff ff <48> 8b 41 28 48 29 ce 48 83 c6 d0 48 c1 ee 04 69 d6 ab aa aa aa 48 [42021.873931] RSP: 0018:ffff97fe90f03da0 EFLAGS: 00010287 [42021.879108] RAX: ffff9406988a8c60 RBX: ffff940e1072d438 RCX: 0000000000000000 [42021.886169] RDX: ffff94085f1aa000 RSI: ffff93c6cbbdbcb0 RDI: ffff940c7517aef0 [42021.893230] RBP: ffff97fe90f03e70 R08: ffff94085f1aa000 R09: 0000000000000000 [42021.900294] R10: ffff94085f1aa000 R11: ffffffffc0775680 R12: ffffffff87ca2530 [42021.907355] R13: ffff940651602840 R14: ffff93c6cbbdbcb0 R15: ffff94085f1aa000 [42021.914418] FS: 00007fda1a3b9700(0000) GS:ffff94453fb80000(0000) knlGS:0000000000000000 [42021.922423] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [42021.928130] CR2: 0000000000000028 CR3: 00000042dcfb8003 CR4: 00000000003726f0 [42021.935194] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [42021.942257] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [42021.949324] Call Trace: [42021.951756] <TASK> [42021.953842] [<ffffffff86c58674>] ? show_regs+0x64/0x70 [42021.959030] [<ffffffff86c58468>] ? __die+0x78/0xc0 [42021.963874] [<ffffffff86c9ef75>] ? page_fault_oops+0x2b5/0x3b0 [42021.969749] [<ffffffff87674b92>] ? exc_page_fault+0x1a2/0x3c0 [42021.975549] [<ffffffff87801326>] ? asm_exc_page_fault+0x26/0x30 [42021.981517] [<ffffffffc0775680>] ? __pfx_show_hw_stats+0x10/0x10 [ib_core] [42021.988482] [<ffffffffc077564e>] ? hw_stat_device_show+0x1e/0x40 [ib_core] [42021.995438] [<ffffffff86ac7f8e>] dev_attr_show+0x1e/0x50 [42022.000803] [<ffffffff86a3eeb1>] sysfs_kf_seq_show+0x81/0xe0 [42022.006508] [<ffffffff86a11134>] seq_read_iter+0xf4/0x410 [42022.011954] [<ffffffff869f4b2e>] vfs_read+0x16e/0x2f0 [42022.017058] [<ffffffff869f50ee>] ksys_read+0x6e/0xe0 [42022.022073] [<ffffffff8766f1ca>] do_syscall_64+0x6a/0xa0 [42022.027441] [<ffffffff8780013b>] entry_SYSCALL_64_after_hwframe+0x78/0xe2 The problem can be reproduced using the following steps: ip netns add foo ip netns exec foo bash cat /sys/class/infiniband/mlx4_0/hw_counters/* The panic occurs because of casting the device pointer into an ib_device pointer using container_of() in hw_stat_device_show() is wrong and leads to a memory corruption. However the real problem is that hw counters should never been exposed outside of the non-init net namespace. Fix this by saving the index of the corresponding attribute group (it might be 1 or 2 depending on the presence of driver-specific attributes) and zeroing the pointer to hw_counters group for compat devices during the initialization. With this fix applied hw_counters are not available in a non-init net namespace: find /sys/class/infiniband/mlx4_0/ -name hw_counters /sys/class/infiniband/mlx4_0/ports/1/hw_counters /sys/class/infiniband/mlx4_0/ports/2/hw_counters /sys/class/infiniband/mlx4_0/hw_counters ip netns add foo ip netns exec foo bash find /sys/class/infiniband/mlx4_0/ -name hw_counters

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux-6.1 0 6.1.137-1~deb11u1
Debian:12 linux 0 No fix
Debian:13 linux 0 No fix
Debian:13 linux 0 6.12.25-1
Linux Kernel 5.14.0 5.15.180
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 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Live Patching 15 SP6 kernel-default 0 6.4.0-150600.23.53.1
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_12 0 1-150600.13.3.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-64kb 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-default-base 0 6.4.0-150600.23.53.1.150600.12.24.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-source 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Basesystem 15 SP6 kernel-zfcpdump 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco 0 6.4.0-15061.28.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-coco_debug 0 6.4.0-15061.28.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-source-coco 0 6.4.0-15061.28.coco15sp6.1
SUSE:Linux Enterprise Module for Confidential Computing Technical Preview 15 SP6 kernel-syms-coco 0 6.4.0-15061.28.coco15sp6.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-docs 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-obs-build 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-source 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Development Tools 15 SP6 kernel-syms 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Legacy 15 SP6 kernel-default 0 6.4.0-150600.23.53.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-azure 0 6.4.0-150600.8.40.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-source-azure 0 6.4.0-150600.8.40.1
SUSE:Linux Enterprise Module for Public Cloud 15 SP6 kernel-syms-azure 0 6.4.0-150600.8.40.1
SUSE:Linux Enterprise Workstation Extension 15 SP6 kernel-default 0 6.4.0-150600.23.53.1
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 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-64kb 0 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-azure 0 6.4.0-150600.8.40.1
openSUSE:Leap 15.6 kernel-debug 0 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-default 0 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-default-base 0 6.4.0-150600.23.53.1.150600.12.24.1
openSUSE:Leap 15.6 kernel-docs 0 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-kvmsmall 0 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-obs-build 0 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-obs-qa 0 6.4.0-150600.23.53.1
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 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-source-azure 0 6.4.0-150600.8.40.1
openSUSE:Leap 15.6 kernel-source-rt 0 6.4.0-150600.10.39.1
openSUSE:Leap 15.6 kernel-syms 0 6.4.0-150600.23.53.1
openSUSE:Leap 15.6 kernel-syms-azure 0 6.4.0-150600.8.40.1
openSUSE:Leap 15.6 kernel-syms-rt 0 6.4.0-150600.10.39.1
openSUSE:Leap 15.6 kernel-zfcpdump 0 6.4.0-150600.23.53.1

Related vulnerabilities