4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit d46401052c2d5614da8efea5788532f0401cb164 ]
ip6_dst_idev() can return NULL, xfrm6_get_saddr() must act accordingly.
syzbot reported:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 12 Comm: kworker/u8:1 Not tainted 6.10.0-rc2-syzkaller-00383-gb8481381d4e2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker
RIP: 0010:xfrm6_get_saddr+0x93/0x130 net/ipv6/xfrm6_policy.c:64
Code: df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 97 00 00 00 4c 8b ab d8 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 86 00 00 00 4d 8b 6d 00 e8 ca 13 47 01 48 b8 00
RSP: 0018:ffffc90000117378 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88807b079dc0 RCX: ffffffff89a0d6d7
RDX: 0000000000000000 RSI: ffffffff89a0d6e9 RDI: ffff88807b079e98
RBP: ffff88807ad73248 R08: 0000000000000007 R09: fffffffffffff000
R10: ffff88807b079dc0 R11: 0000000000000007 R12: ffffc90000117480
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4586d00440 CR3: 0000000079042000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
xfrm_get_saddr net/xfrm/xfrm_policy.c:2452 [inline]
xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2481 [inline]
xfrm_tmpl_resolve+0xa26/0xf10 net/xfrm/xfrm_policy.c:2541
xfrm_resolve_and_create_bundle+0x140/0x2570 net/xfrm/xfrm_policy.c:2835
xfrm_bundle_lookup net/xfrm/xfrm_policy.c:3070 [inline]
xfrm_lookup_with_ifid+0x4d1/0x1e60 net/xfrm/xfrm_policy.c:3201
xfrm_lookup net/xfrm/xfrm_policy.c:3298 [inline]
xfrm_lookup_route+0x3b/0x200 net/xfrm/xfrm_policy.c:3309
ip6_dst_lookup_flow+0x15c/0x1d0 net/ipv6/ip6_output.c:1256
send6+0x611/0xd20 drivers/net/wireguard/socket.c:139
wg_socket_send_skb_to_peer+0xf9/0x220 drivers/net/wireguard/socket.c:178
wg_socket_send_buffer_to_peer+0x12b/0x190 drivers/net/wireguard/socket.c:200
wg_packet_send_handshake_initiation+0x227/0x360 drivers/net/wireguard/send.c:40
wg_packet_handshake_send_worker+0x1c/0x30 drivers/net/wireguard/send.c:51
process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
process_scheduled_works kernel/workqueue.c:3312 [inline]
worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: David Ahern <dsahern@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240615154231.234442-1-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv6/xfrm6_policy.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index a1dfe4f5ed3a4..086f34d2051a1 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -60,12 +60,18 @@ static int xfrm6_get_saddr(struct net *net, int oif,
{
struct dst_entry *dst;
struct net_device *dev;
+ struct inet6_dev *idev;
dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark);
if (IS_ERR(dst))
return -EHOSTUNREACH;
- dev = ip6_dst_idev(dst)->dev;
+ idev = ip6_dst_idev(dst);
+ if (!idev) {
+ dst_release(dst);
+ return -EHOSTUNREACH;
+ }
+ dev = idev->dev;
ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
dst_release(dst);
return 0;
--
2.43.0
