CVE-2025-38048: Linux kernel · virtio_ring: Fix data race by tagging
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 4.7 Medium · fixed in 5.15.0-1090.97~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 16:39 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1090.97~20.04.1, 5.15.0-1094.103~20.04.1, 5.15.0-1114.123~20.04.1 +64
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Jun 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7704-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7711-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7769-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7770-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7771-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7769-2 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-aws-6.14pkg:deb/ubuntu/linux-aws-6.14?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: virtio_ring: Fix data race by tagging event_triggered as racy for KCSAN syzbot reports a data-race when accessing the event_triggered, here is the simplified stack when the issue occurred: ================================================================== BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_enable_cb_delayed write to 0xffff8881025bc452 of 1 bytes by task 3288 on cpu 0: virtqueue_enable_cb_delayed+0x42/0x3c0 drivers/virtio/virtio_ring.c:2653 start_xmit+0x230/0x1310 drivers/net/virtio_net.c:3264 __netdev_start_xmit include/linux/netdevice.h:5151 [inline] netdev_start_xmit include/linux/netdevice.h:5160 [inline] xmit_one net/core/dev.c:3800 [inline] read to 0xffff8881025bc452 of 1 bytes by interrupt on cpu 1: virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:880 [inline] virtqueue_disable_cb+0x92/0x180 drivers/virtio/virtio_ring.c:2566 skb_xmit_done+0x5f/0x140 drivers/net/virtio_net.c:777 vring_interrupt+0x161/0x190 drivers/virtio/virtio_ring.c:2715 __handle_irq_event_percpu+0x95/0x490 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] value changed: 0x01 -> 0x00 ================================================================== When the data race occurs, the function virtqueue_enable_cb_delayed() sets event_triggered to false, and virtqueue_disable_cb_split/packed() reads it as false due to the race condition. Since event_triggered is an unreliable hint used for optimization, this should only cause the driver temporarily suggest that the device not send an interrupt notification when the event index is used. Fix this KCSAN reported data-race issue by explicitly tagging the access as data_racy.
References
- ubuntu.com/security/CVE-2025-38048 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-38048 (opens in a new tab)
- git.kernel.org/linus/2e2f925fe737576df2373931c95e1a2b66efdfef (opens in a new tab)
- git.kernel.org/stable/c/02d2d6caee3abc9335cfca35f8eb4492173ae6f2 (opens in a new tab)
- git.kernel.org/stable/c/2e2f925fe737576df2373931c95e1a2b66efdfef (opens in a new tab)
- git.kernel.org/stable/c/4ed8f0e808b3fcc71c5b8be7902d8738ed595b17 (opens in a new tab)
- git.kernel.org/stable/c/b49b5132e4c7307599492aee1cdc6d89f7f2a7da (opens in a new tab)
- git.kernel.org/stable/c/b6d6419548286b2b9d2b90df824d3cab797f6ae8 (opens in a new tab)
- git.kernel.org/stable/c/b730cb109633c455ce8a7cd6934986c6a16d88d8 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7711-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7704-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7712-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7769-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7770-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7771-1 (opens in a new tab)