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

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History

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

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-04-22T13:54:24.524Z

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

Link: CVE-2026-31505

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

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

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

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: 2026-04-22T18:00:05Z

Weaknesses