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CVE-2025-38037
published 2025-06-18

CVE-2025-38037: 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…

medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
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 &

Affected

35 ranges· showing 25
VendorProductVersion rangeFixed in
debiandebian_linux
debianlinux< linux 6.1.147-1 (bookworm)linux 6.1.147-1 (bookworm)
debianlinux-6.1< linux 6.1.147-1 (bookworm)linux 6.1.147-1 (bookworm)
linuxlinux
linuxlinux>= d342894c5d2f8c7df194c793ec4059656e09ca31 < 02a33b1035a307453a1da6ce0a1bf3676be287d702a33b1035a307453a1da6ce0a1bf3676be287d7
linuxlinux>= d342894c5d2f8c7df194c793ec4059656e09ca31 < 87d076987a9ba106c83412fcd113656f71af05a187d076987a9ba106c83412fcd113656f71af05a1
linuxlinux>= d342894c5d2f8c7df194c793ec4059656e09ca31 < e033da39fc6abbddab6c29624acef80757f273fae033da39fc6abbddab6c29624acef80757f273fa
linuxlinux>= d342894c5d2f8c7df194c793ec4059656e09ca31 < 784b78295a3a58bf052339dd669e6e03710220d3784b78295a3a58bf052339dd669e6e03710220d3
linuxlinux>= d342894c5d2f8c7df194c793ec4059656e09ca31 < 13cba3f837903f7184d6e9b6137d5165ffe82a8f13cba3f837903f7184d6e9b6137d5165ffe82a8f
linuxlinux>= d342894c5d2f8c7df194c793ec4059656e09ca31 < a6644aeb8ddf196dec5f8e782293c36f065df4d7a6644aeb8ddf196dec5f8e782293c36f065df4d7
linuxlinux>= d342894c5d2f8c7df194c793ec4059656e09ca31 < 4eceb7eae6ea7c950384c34e6dbbe872c981935f4eceb7eae6ea7c950384c34e6dbbe872c981935f
linuxlinux>= d342894c5d2f8c7df194c793ec4059656e09ca31 < f6205f8215f12a96518ac9469ff76294ae7bd612f6205f8215f12a96518ac9469ff76294ae7bd612
linuxlinux_kernel>= 0 < 5.10.244-15.10.244-1
linuxlinux_kernel>= 0 < 6.1.147-16.1.147-1
linuxlinux_kernel>= 0 < 6.12.32-16.12.32-1
linuxlinux_kernel>= 0 < 6.12.32-16.12.32-1
linuxlinux_kernel>= 0 < 5.15.0-152.1625.15.0-152.162
linuxlinux_kernel>= 0 < 6.8.0-100.1006.8.0-100.100
linuxlinux_kernel>= 3.7 < 5.4.2945.4.294
linuxlinux_kernel>= 5.11 < 5.15.1855.15.185
linuxlinux_kernel>= 5.16 < 6.1.1416.1.141
linuxlinux_kernel>= 5.5 < 5.10.2385.10.238
linuxlinux_kernel>= 6.13 < 6.14.96.14.9
linuxlinux_kernel>= 6.2 < 6.6.936.6.93
linuxlinux_kernel>= 6.7 < 6.12.316.12.31

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM