mirror-linux/include
Xiang Mei b3a6df291f udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n
When CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0
(success) without actually creating a socket. Callers such as
fou_create() then proceed to dereference the uninitialized socket
pointer, resulting in a NULL pointer dereference.

The captured NULL deref crash:
  BUG: kernel NULL pointer dereference, address: 0000000000000018
  RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764)
  [...]
  Call Trace:
    <TASK>
    genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114)
    genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209)
    [...]
    netlink_rcv_skb (net/netlink/af_netlink.c:2550)
    genl_rcv (net/netlink/genetlink.c:1219)
    netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
    netlink_sendmsg (net/netlink/af_netlink.c:1894)
    __sock_sendmsg (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1))
    __sys_sendto (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:2183 (discriminator 1))
    __x64_sys_sendto (net/socket.c:2213 (discriminator 1) net/socket.c:2209 (discriminator 1) net/socket.c:2209 (discriminator 1))
    do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
    entry_SYSCALL_64_after_hwframe (net/arch/x86/entry/entry_64.S:130)

This patch makes udp_sock_create6 return -EPFNOSUPPORT instead, so
callers correctly take their error paths. There is only one caller of
the vulnerable function and only privileged users can trigger it.

Fixes: fd384412e1 ("udp_tunnel: Seperate ipv6 functions into its own file.")
Reported-by: Weiming Shi <bestswngs@gmail.com>
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Link: https://patch.msgid.link/20260317010241.1893893-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-18 18:00:07 -07:00
..
acpi mailbox: platform and core updates 2026-02-14 11:13:32 -08:00
asm-generic kbuild: Split .modinfo out from ELF_DETAILS 2026-02-26 11:50:19 -07:00
clocksource
crypto Networking changes for 7.0 2026-02-11 19:31:52 -08:00
cxl
drm drm/dp: Add definition for Panel Replay full-line granularity 2026-03-04 15:26:08 +02:00
dt-bindings phy-for-7.0 2026-02-17 11:40:04 -08:00
hyperv hyperv-next for v7.0 2026-02-20 08:48:31 -08:00
keys
kunit kunit: irq: Ensure timer doesn't fire too frequently 2026-02-24 14:44:21 -08:00
kvm
linux bonding: prevent potential infinite loop in bond_header_parse() 2026-03-16 19:29:45 -07:00
math-emu
media
memory
misc
net udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n 2026-03-18 18:00:07 -07:00
pcmcia
ras
rdma RDMA/core: Check id_priv->restricted_node_type in cma_listen_on_dev() 2026-02-25 07:50:10 -05:00
rv rv: Fix multiple definition of __pcpu_unique_da_mon_this 2026-02-20 13:12:00 +01:00
scsi SCSI misc on 20260212 2026-02-12 15:43:02 -08:00
soc
sound ASoC: Fixes for v7.0 2026-03-05 17:22:14 +01:00
target
trace vfs-7.0-rc3.fixes 2026-03-04 15:03:16 -08:00
uapi drm fixes for 7.0-rc3 2026-03-06 13:29:12 -08:00
ufs
vdso
video
xen xen/xenbus: better handle backend crash 2026-03-04 15:31:40 +01:00
Kbuild