From a5c5e2da8551eb69e5d5d09d51d526140b5db9fb Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Wed, 8 Jun 2016 12:59:17 +0200 Subject: [PATCH] l2tp: fix configuration passed to setup_udp_tunnel_sock() Unused fields of udp_cfg must be all zeros. Otherwise setup_udp_tunnel_sock() fills ->gro_receive and ->gro_complete callbacks with garbage, eventually resulting in panic when used by udp_gro_receive(). [ 72.694123] BUG: unable to handle kernel paging request at ffff880033f87d78 [ 72.695518] IP: [] 0xffff880033f87d78 [ 72.696530] PGD 26e2067 PUD 26e3067 PMD 342ed063 PTE 8000000033f87163 [ 72.696530] Oops: 0011 [#1] SMP KASAN [ 72.696530] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6_udp_tunnel udp_tunnel pptp gre pppox ppp_generic slhc crc32c_intel ghash_clmulni_intel jitterentropy_rng sha256_generic hmac drbg ansi_cprng aesni_intel evdev aes_x86_64 ablk_helper cryptd lrw gf128mul glue_helper serio_raw acpi_cpufreq button proc\ essor ext4 crc16 jbd2 mbcache virtio_blk virtio_net virtio_pci virtio_ring virtio [ 72.696530] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.7.0-rc1 #1 [ 72.696530] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 72.696530] task: ffff880035b59700 ti: ffff880035b70000 task.ti: ffff880035b70000 [ 72.696530] RIP: 0010:[] [] 0xffff880033f87d78 [ 72.696530] RSP: 0018:ffff880035f87bc0 EFLAGS: 00010246 [ 72.696530] RAX: ffffed000698f996 RBX: ffff88003326b840 RCX: ffffffff814cc823 [ 72.696530] RDX: ffff88003326b840 RSI: ffff880033e48038 RDI: ffff880034c7c780 [ 72.696530] RBP: ffff880035f87c18 R08: 000000000000a506 R09: 0000000000000000 [ 72.696530] R10: ffff880035f87b38 R11: ffff880034b9344d R12: 00000000ebfea715 [ 72.696530] R13: 0000000000000000 R14: ffff880034c7c780 R15: 0000000000000000 [ 72.696530] FS: 0000000000000000(0000) GS:ffff880035f80000(0000) knlGS:0000000000000000 [ 72.696530] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 72.696530] CR2: ffff880033f87d78 CR3: 0000000033c98000 CR4: 00000000000406a0 [ 72.696530] Stack: [ 72.696530] ffffffff814cc834 ffff880034b93468 0000001481416818 ffff88003326b874 [ 72.696530] ffff880034c7ccb0 ffff880033e48038 ffff88003326b840 ffff880034b93462 [ 72.696530] ffff88003326b88a ffff88003326b88c ffff880034b93468 ffff880035f87c70 [ 72.696530] Call Trace: [ 72.696530] [ 72.696530] [] ? udp_gro_receive+0x1c6/0x1f9 [ 72.696530] [] udp4_gro_receive+0x2b5/0x310 [ 72.696530] [] inet_gro_receive+0x4a3/0x4cd [ 72.696530] [] dev_gro_receive+0x584/0x7a3 [ 72.696530] [] ? __lock_is_held+0x29/0x64 [ 72.696530] [] napi_gro_receive+0x124/0x21d [ 72.696530] [] virtnet_receive+0x8df/0x8f6 [virtio_net] [ 72.696530] [] virtnet_poll+0x1d/0x8d [virtio_net] [ 72.696530] [] net_rx_action+0x15b/0x3b9 [ 72.696530] [] __do_softirq+0x216/0x546 [ 72.696530] [] irq_exit+0x49/0xb6 [ 72.696530] [] do_IRQ+0xe2/0xfa [ 72.696530] [] common_interrupt+0x89/0x89 [ 72.696530] [ 72.696530] [] ? trace_hardirqs_on_caller+0x229/0x270 [ 72.696530] [] ? default_idle+0x1c/0x2d [ 72.696530] [] ? default_idle+0x1a/0x2d [ 72.696530] [] arch_cpu_idle+0xa/0xc [ 72.696530] [] default_idle_call+0x1a/0x1c [ 72.696530] [] cpu_startup_entry+0x15b/0x20f [ 72.696530] [] start_secondary+0x12c/0x133 [ 72.696530] Code: ff ff ff ff ff ff ff ff ff ff 7f ff ff ff ff ff ff ff 7f 00 7e f8 33 00 88 ff ff 6d 61 58 81 ff ff ff ff 5e de 0a 81 ff ff ff ff <00> 5c e2 34 00 88 ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 72.696530] RIP [] 0xffff880033f87d78 [ 72.696530] RSP [ 72.696530] CR2: ffff880033f87d78 [ 72.696530] ---[ end trace ad7758b9a1dccf99 ]--- [ 72.696530] Kernel panic - not syncing: Fatal exception in interrupt [ 72.696530] Kernel Offset: disabled [ 72.696530] ---[ end Kernel panic - not syncing: Fatal exception in interrupt v2: use empty initialiser instead of "{ NULL }" to avoid relying on first field's type. Fixes: 38fd2af24fcf ("udp: Add socket based GRO and config") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller --- net/l2tp/l2tp_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 6edfa9980314..1e40dacaa137 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1581,7 +1581,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ tunnel->encap = encap; if (encap == L2TP_ENCAPTYPE_UDP) { - struct udp_tunnel_sock_cfg udp_cfg; + struct udp_tunnel_sock_cfg udp_cfg = { }; udp_cfg.sk_user_data = tunnel; udp_cfg.encap_type = UDP_ENCAP_L2TPINUDP; -- 2.20.1