Description
In the Linux kernel, the following vulnerability has been resolved:

iavf: fix out-of-bounds writes in iavf_get_ethtool_stats()

iavf incorrectly uses real_num_tx_queues for ETH_SS_STATS. Since the
value could change in runtime, we should use num_tx_queues instead.

Moreover iavf_get_ethtool_stats() uses num_active_queues while
iavf_get_sset_count() and iavf_get_stat_strings() use
real_num_tx_queues, which triggers out-of-bounds writes when we do
"ethtool -L" and "ethtool -S" simultaneously [1].

For example when we change channels from 1 to 8, Thread 3 could be
scheduled before Thread 2, and out-of-bounds writes could be triggered
in Thread 3:

Thread 1 (ethtool -L) Thread 2 (work) Thread 3 (ethtool -S)
iavf_set_channels()
...
iavf_alloc_queues()
-> num_active_queues = 8
iavf_schedule_finish_config()
iavf_get_sset_count()
real_num_tx_queues: 1
-> buffer for 1 queue
iavf_get_ethtool_stats()
num_active_queues: 8
-> out-of-bounds!
iavf_finish_config()
-> real_num_tx_queues = 8

Use immutable num_tx_queues in all related functions to avoid the issue.

[1]
BUG: KASAN: vmalloc-out-of-bounds in iavf_add_one_ethtool_stat+0x200/0x270
Write of size 8 at addr ffffc900031c9080 by task ethtool/5800

CPU: 1 UID: 0 PID: 5800 Comm: ethtool Not tainted 6.19.0-enjuk-08403-g8137e3db7f1c #241 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x6f/0xb0
print_report+0x170/0x4f3
kasan_report+0xe1/0x180
iavf_add_one_ethtool_stat+0x200/0x270
iavf_get_ethtool_stats+0x14c/0x2e0
__dev_ethtool+0x3d0c/0x5830
dev_ethtool+0x12d/0x270
dev_ioctl+0x53c/0xe30
sock_do_ioctl+0x1a9/0x270
sock_ioctl+0x3d4/0x5e0
__x64_sys_ioctl+0x137/0x1c0
do_syscall_64+0xf3/0x690
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7da0e6e36d
...
</TASK>

The buggy address belongs to a 1-page vmalloc region starting at 0xffffc900031c9000 allocated at __dev_ethtool+0x3cc9/0x5830
The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000
index:0xffff88813a013de0 pfn:0x13a013
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000
raw: ffff88813a013de0 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffffc900031c8f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc900031c9000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900031c9080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
^
ffffc900031c9100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc900031c9180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
Published: 2026-04-22
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: Kernel memory corruption
Action: Patch Now
AI Analysis

Impact

In the iavf driver for the Linux kernel, a race between channel reconfiguration (ethtool -L) and statistics retrieval (ethtool -S) causes the driver to use inconsistent queue counters, leading to out‑of‑bounds writes into the statistics buffer. This buffer overflow (CWE‑805 and CWE‑787) can corrupt kernel memory, trigger a crash, or, if an attacker can control the overwrite, enable local privilege escalation. The vulnerability directly impacts kernel integrity and availability, with potential secondary effects on confidentiality if memory corruption leaks sensitive data.

Affected Systems

The flaw exists in all Linux kernel releases that ship the unpatched iavf driver, including the 6.19.0 kernel and earlier. The patch that fixes the issue is identified by commit 1f931dee5b726df1940348ec31614d64bac03aa6 and is referenced in the advisory links. Kernels that have not yet incorporated this commit remain vulnerable.

Risk and Exploitability

The CVSS score for this vulnerability is 7.8, indicating a high severity. The EPSS score is reported as less than 1 %, and it is not listed in the CISA KEV catalog. Based on the description, it is inferred that the ethtool command generally requires root or CAP_SYS_ADMIN privileges. Therefore, the exploit is limited to local users with elevated privileges, reducing the likelihood of widespread compromise but still presenting a significant risk for systems that allow such users to perform channel configuration and statistics queries simultaneously.

Generated by OpenCVE AI on April 28, 2026 at 20:50 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Update the Linux kernel to a version that includes commit 1f931dee5b726df1940348ec31614d64bac03aa6, which removes the out‑of‑bounds write (CWE‑805).
  • Avoid running ethtool –L and –S at the same time; apply channel changes and retrieve statistics in separate sessions to eliminate the race condition.
  • If a kernel upgrade cannot be performed immediately, restrict the privileges of ethtool by applying SELinux or AppArmor policies that deny CAP_SYS_ADMIN for the command and monitor dmesg or journal logs for KASAN or Oops messages indicating residual corruption.

Generated by OpenCVE AI on April 28, 2026 at 20:50 UTC.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Debian DSA Debian DSA DSA-6238-1 linux security update
History

Tue, 28 Apr 2026 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-787
CPEs cpe:2.3:o:linux:linux_kernel:5.17:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*

Mon, 27 Apr 2026 15:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

 cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Thu, 23 Apr 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-805
References
Metrics threat_severity

None

 cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate

Wed, 22 Apr 2026 14:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: iavf: fix out-of-bounds writes in iavf_get_ethtool_stats() iavf incorrectly uses real_num_tx_queues for ETH_SS_STATS. Since the value could change in runtime, we should use num_tx_queues instead. Moreover iavf_get_ethtool_stats() uses num_active_queues while iavf_get_sset_count() and iavf_get_stat_strings() use real_num_tx_queues, which triggers out-of-bounds writes when we do "ethtool -L" and "ethtool -S" simultaneously [1]. For example when we change channels from 1 to 8, Thread 3 could be scheduled before Thread 2, and out-of-bounds writes could be triggered in Thread 3: Thread 1 (ethtool -L) Thread 2 (work) Thread 3 (ethtool -S) iavf_set_channels() ... iavf_alloc_queues() -> num_active_queues = 8 iavf_schedule_finish_config() iavf_get_sset_count() real_num_tx_queues: 1 -> buffer for 1 queue iavf_get_ethtool_stats() num_active_queues: 8 -> out-of-bounds! iavf_finish_config() -> real_num_tx_queues = 8 Use immutable num_tx_queues in all related functions to avoid the issue. [1] BUG: KASAN: vmalloc-out-of-bounds in iavf_add_one_ethtool_stat+0x200/0x270 Write of size 8 at addr ffffc900031c9080 by task ethtool/5800 CPU: 1 UID: 0 PID: 5800 Comm: ethtool Not tainted 6.19.0-enjuk-08403-g8137e3db7f1c #241 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x6f/0xb0 print_report+0x170/0x4f3 kasan_report+0xe1/0x180 iavf_add_one_ethtool_stat+0x200/0x270 iavf_get_ethtool_stats+0x14c/0x2e0 __dev_ethtool+0x3d0c/0x5830 dev_ethtool+0x12d/0x270 dev_ioctl+0x53c/0xe30 sock_do_ioctl+0x1a9/0x270 sock_ioctl+0x3d4/0x5e0 __x64_sys_ioctl+0x137/0x1c0 do_syscall_64+0xf3/0x690 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7da0e6e36d ... </TASK> The buggy address belongs to a 1-page vmalloc region starting at 0xffffc900031c9000 allocated at __dev_ethtool+0x3cc9/0x5830 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88813a013de0 pfn:0x13a013 flags: 0x200000000000000(node=0|zone=2) raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000 raw: ffff88813a013de0 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffffc900031c8f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900031c9000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffffc900031c9080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffffc900031c9100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffffc900031c9180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
Title iavf: fix out-of-bounds writes in iavf_get_ethtool_stats()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T22:10:03.459Z

Reserved: 2026-03-09T15:48:24.105Z

Link: CVE-2026-31505

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2026-04-22T14:16:49.233

Modified: 2026-04-28T15:06:25.950

Link: CVE-2026-31505

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-04-22T00:00:00Z

Links: CVE-2026-31505 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-04-28T21:00:14Z

Weaknesses