diff options
| author | Fernando Fernandez Mancera <fmancera@suse.de> | 2026-03-04 13:03:57 +0100 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2026-03-12 07:10:01 -0400 |
| commit | fbbd2118982c55fb9b0a753ae0cf7194e77149fb (patch) | |
| tree | 59e0fd498d88246cc8145f4b3f037efde9c0e740 | |
| parent | 33dec6f10777d5a8f71c0a200f690da5ae3c2e55 (diff) | |
| download | linux-fbbd2118982c55fb9b0a753ae0cf7194e77149fb.tar.gz linux-fbbd2118982c55fb9b0a753ae0cf7194e77149fb.tar.bz2 linux-fbbd2118982c55fb9b0a753ae0cf7194e77149fb.zip | |
net: vxlan: fix nd_tbl NULL dereference when IPv6 is disabled
[ Upstream commit 168ff39e4758897d2eee4756977d036d52884c7e ]
When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never
initialized because inet6_init() exits before ndisc_init() is called
which initializes it. If an IPv6 packet is injected into the interface,
route_shortcircuit() is called and a NULL pointer dereference happens on
neigh_lookup().
BUG: kernel NULL pointer dereference, address: 0000000000000380
Oops: Oops: 0000 [#1] SMP NOPTI
[...]
RIP: 0010:neigh_lookup+0x20/0x270
[...]
Call Trace:
<TASK>
vxlan_xmit+0x638/0x1ef0 [vxlan]
dev_hard_start_xmit+0x9e/0x2e0
__dev_queue_xmit+0xbee/0x14e0
packet_sendmsg+0x116f/0x1930
__sys_sendto+0x1f5/0x200
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x12f/0x1590
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fix this by adding an early check on route_shortcircuit() when protocol
is ETH_P_IPV6. Note that ipv6_mod_enabled() cannot be used here because
VXLAN can be built-in even when IPv6 is built as a module.
Fixes: e15a00aafa4b ("vxlan: add ipv6 route short circuit support")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260304120357.9778-2-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/net/vxlan/vxlan_core.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index e957aa12a8a4..2a140be86baf 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -2130,6 +2130,11 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb) { struct ipv6hdr *pip6; + /* check if nd_tbl is not initiliazed due to + * ipv6.disable=1 set during boot + */ + if (!ipv6_stub->nd_tbl) + return false; if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) return false; pip6 = ipv6_hdr(skb); |