In the Linux kernel, the following vulnerability has been resolved:
vxlan: Annotate FDB data races
The 'used' and 'updated' fields in the FDB entry structure can be
accessed concurrently by multiple threads, leading to reports such as
[1]. Can be reproduced using [2].
Suppress these reports by annotating these accesses using
READ_ONCE() / WRITE_ONCE().
[1]
BUG: KCSAN: data-race in vxlan_xmit / vxlan_xmit
write to 0xffff942604d263a8 of 8 bytes by task 286 on cpu 0:
vxlan_xmit+0xb29/0x2380
dev_hard_start_xmit+0x84/0x2f0
__dev_queue_xmit+0x45a/0x1650
packet_xmit+0x100/0x150
packet_sendmsg+0x2114/0x2ac0
__sys_sendto+0x318/0x330
__x64_sys_sendto+0x76/0x90
x64_sys_call+0x14e8/0x1c00
do_syscall_64+0x9e/0x1a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffff942604d263a8 of 8 bytes by task 287 on cpu 2:
vxlan_xmit+0xadf/0x2380
dev_hard_start_xmit+0x84/0x2f0
__dev_queue_xmit+0x45a/0x1650
packet_xmit+0x100/0x150
packet_sendmsg+0x2114/0x2ac0
__sys_sendto+0x318/0x330
__x64_sys_sendto+0x76/0x90
x64_sys_call+0x14e8/0x1c00
do_syscall_64+0x9e/0x1a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x00000000fffbac6e -> 0x00000000fffbac6f
Reported by Kernel Concurrency Sanitizer on:
CPU: 2 UID: 0 PID: 287 Comm: mausezahn Not tainted 6.13.0-rc7-01544-gb4b270f11a02 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014
[2]
#!/bin/bash
set +H
echo whitelist > /sys/kernel/debug/kcsan
echo !vxlan_xmit > /sys/kernel/debug/kcsan
ip link add name vx0 up type vxlan id 10010 dstport 4789 local 192.0.2.1
bridge fdb add 00:11:22:33:44:55 dev vx0 self static dst 198.51.100.1
taskset -c 0 mausezahn vx0 -a own -b 00:11:22:33:44:55 -c 0 -q &
taskset -c 2 mausezahn vx0 -a own -b 00:11:22:33:44:55 -c 0 -q &
References
Configurations
Configuration 1 (hide)
|
Configuration 2 (hide)
|
History
18 Dec 2025, 21:36
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| CWE | NVD-CWE-noinfo | |
| CPE | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
|
| First Time |
Linux
Debian Debian debian Linux Linux linux Kernel |
|
| References | () https://git.kernel.org/stable/c/02a33b1035a307453a1da6ce0a1bf3676be287d7 - Patch | |
| References | () https://git.kernel.org/stable/c/13cba3f837903f7184d6e9b6137d5165ffe82a8f - Patch | |
| References | () https://git.kernel.org/stable/c/4eceb7eae6ea7c950384c34e6dbbe872c981935f - Patch | |
| References | () https://git.kernel.org/stable/c/784b78295a3a58bf052339dd669e6e03710220d3 - Patch | |
| References | () https://git.kernel.org/stable/c/87d076987a9ba106c83412fcd113656f71af05a1 - Patch | |
| References | () https://git.kernel.org/stable/c/a6644aeb8ddf196dec5f8e782293c36f065df4d7 - Patch | |
| References | () https://git.kernel.org/stable/c/e033da39fc6abbddab6c29624acef80757f273fa - Patch | |
| References | () https://git.kernel.org/stable/c/f6205f8215f12a96518ac9469ff76294ae7bd612 - Patch | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html - Third Party Advisory | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory |
03 Nov 2025, 18:15
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
|
| Summary |
|
18 Jun 2025, 10:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-06-18 10:15
Updated : 2025-12-18 21:36
NVD link : CVE-2025-38037
Mitre link : CVE-2025-38037
CVE.ORG link : CVE-2025-38037
JSON object : View
Products Affected
debian
- debian_linux
linux
- linux_kernel
CWE
