Description

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

vxlan: Fix uninit-value in vxlan_vnifilter_dump()

KMSAN reported an uninit-value access in vxlan_vnifilter_dump() [1].

If the length of the netlink message payload is less than
sizeof(struct tunnel_msg), vxlan_vnifilter_dump() accesses bytes
beyond the message. This can lead to uninit-value access. Fix this by
returning an error in such situations.

[1]
BUG: KMSAN: uninit-value in vxlan_vnifilter_dump+0x328/0x920 drivers/net/vxlan/vxlan_vnifilter.c:422
vxlan_vnifilter_dump+0x328/0x920 drivers/net/vxlan/vxlan_vnifilter.c:422
rtnl_dumpit+0xd5/0x2f0 net/core/rtnetlink.c:6786
netlink_dump+0x93e/0x15f0 net/netlink/af_netlink.c:2317
__netlink_dump_start+0x716/0xd60 net/netlink/af_netlink.c:2432
netlink_dump_start include/linux/netlink.h:340 [inline]
rtnetlink_dump_start net/core/rtnetlink.c:6815 [inline]
rtnetlink_rcv_msg+0x1256/0x14a0 net/core/rtnetlink.c:6882
netlink_rcv_skb+0x467/0x660 net/netlink/af_netlink.c:2542
rtnetlink_rcv+0x35/0x40 net/core/rtnetlink.c:6944
netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
netlink_unicast+0xed6/0x1290 net/netlink/af_netlink.c:1347
netlink_sendmsg+0x1092/0x1230 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:711 [inline]
__sock_sendmsg+0x330/0x3d0 net/socket.c:726
____sys_sendmsg+0x7f4/0xb50 net/socket.c:2583
___sys_sendmsg+0x271/0x3b0 net/socket.c:2637
__sys_sendmsg net/socket.c:2669 [inline]
__do_sys_sendmsg net/socket.c:...

Classification

CVE ID: CVE-2025-21716

Affected Products

Vendor: Linux, Linux

Product: Linux, Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.02% (probability of being exploited)

EPSS Percentile: 1.72% (scored less or equal to compared to others)

EPSS Date: 2025-03-27 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-21716
https://git.kernel.org/stable/c/cb1de9309a48cc5b771115781eec05075fd67039
https://git.kernel.org/stable/c/a84d511165d6ba7f331b90ae6b6ce180ec534daa
https://git.kernel.org/stable/c/f554bce488605d2f70e06eeab5e4d2448c813713
https://git.kernel.org/stable/c/1693d1fade71646a0731b6b213298cb443d186ea
https://git.kernel.org/stable/c/5066293b9b7046a906eff60e3949a887ae185a43

Timeline