From 51d4740f88affd85d49c04e3c9cd129c0e33bcb9 Mon Sep 17 00:00:00 2001 From: Roman Mashak Date: Mon, 12 Mar 2018 16:20:58 -0400 Subject: net sched actions: return explicit error when tunnel_key mode is not specified If set/unset mode of the tunnel_key action is not provided, ->init() still returns 0, and the caller proceeds with bogus 'struct tc_action *' object, this results in crash: % tc actions add action tunnel_key src_ip 1.1.1.1 dst_ip 2.2.2.1 id 7 index 1 [ 35.805515] general protection fault: 0000 [#1] SMP PTI [ 35.806161] Modules linked in: act_tunnel_key kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd glue_helper cryptd serio_raw [ 35.808233] CPU: 1 PID: 428 Comm: tc Not tainted 4.16.0-rc4+ #286 [ 35.808929] RIP: 0010:tcf_action_init+0x90/0x190 [ 35.809457] RSP: 0018:ffffb8edc068b9a0 EFLAGS: 00010206 [ 35.810053] RAX: 1320c000000a0003 RBX: 0000000000000001 RCX: 0000000000000000 [ 35.810866] RDX: 0000000000000070 RSI: 0000000000007965 RDI: ffffb8edc068b910 [ 35.811660] RBP: ffffb8edc068b9d0 R08: 0000000000000000 R09: ffffb8edc068b808 [ 35.812463] R10: ffffffffc02bf040 R11: 0000000000000040 R12: ffffb8edc068bb38 [ 35.813235] R13: 0000000000000000 R14: 0000000000000000 R15: ffffb8edc068b910 [ 35.814006] FS: 00007f3d0d8556c0(0000) GS:ffff91d1dbc40000(0000) knlGS:0000000000000000 [ 35.814881] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 35.815540] CR2: 000000000043f720 CR3: 0000000019248001 CR4: 00000000001606a0 [ 35.816457] Call Trace: [ 35.817158] tc_ctl_action+0x11a/0x220 [ 35.817795] rtnetlink_rcv_msg+0x23d/0x2e0 [ 35.818457] ? __slab_alloc+0x1c/0x30 [ 35.819079] ? __kmalloc_node_track_caller+0xb1/0x2b0 [ 35.819544] ? rtnl_calcit.isra.30+0xe0/0xe0 [ 35.820231] netlink_rcv_skb+0xce/0x100 [ 35.820744] netlink_unicast+0x164/0x220 [ 35.821500] netlink_sendmsg+0x293/0x370 [ 35.822040] sock_sendmsg+0x30/0x40 [ 35.822508] ___sys_sendmsg+0x2c5/0x2e0 [ 35.823149] ? pagecache_get_page+0x27/0x220 [ 35.823714] ? filemap_fault+0xa2/0x640 [ 35.824423] ? page_add_file_rmap+0x108/0x200 [ 35.825065] ? alloc_set_pte+0x2aa/0x530 [ 35.825585] ? finish_fault+0x4e/0x70 [ 35.826140] ? __handle_mm_fault+0xbc1/0x10d0 [ 35.826723] ? __sys_sendmsg+0x41/0x70 [ 35.827230] __sys_sendmsg+0x41/0x70 [ 35.827710] do_syscall_64+0x68/0x120 [ 35.828195] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 [ 35.828859] RIP: 0033:0x7f3d0ca4da67 [ 35.829331] RSP: 002b:00007ffc9f284338 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 35.830304] RAX: ffffffffffffffda RBX: 00007ffc9f284460 RCX: 00007f3d0ca4da67 [ 35.831247] RDX: 0000000000000000 RSI: 00007ffc9f2843b0 RDI: 0000000000000003 [ 35.832167] RBP: 000000005aa6a7a9 R08: 0000000000000001 R09: 0000000000000000 [ 35.833075] R10: 00000000000005f1 R11: 0000000000000246 R12: 0000000000000000 [ 35.833997] R13: 00007ffc9f2884c0 R14: 0000000000000001 R15: 0000000000674640 [ 35.834923] Code: 24 30 bb 01 00 00 00 45 31 f6 eb 5e 8b 50 08 83 c2 07 83 e2 fc 83 c2 70 49 8b 07 48 8b 40 70 48 85 c0 74 10 48 89 14 24 4c 89 ff d0 48 8b 14 24 48 01 c2 49 01 d6 45 85 ed 74 05 41 83 47 2c [ 35.837442] RIP: tcf_action_init+0x90/0x190 RSP: ffffb8edc068b9a0 [ 35.838291] ---[ end trace a095c06ee4b97a26 ]--- Fixes: d0f6dd8a914f ("net/sched: Introduce act_tunnel_key") Signed-off-by: Roman Mashak Acked-by: Cong Wang Signed-off-by: David S. Miller --- net/sched/act_tunnel_key.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/sched/act_tunnel_key.c') diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c index 0e23aac09ad6..fea772e66e62 100644 --- a/net/sched/act_tunnel_key.c +++ b/net/sched/act_tunnel_key.c @@ -153,6 +153,7 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla, metadata->u.tun_info.mode |= IP_TUNNEL_INFO_TX; break; default: + ret = -EINVAL; goto err_out; } -- cgit v1.2.3-59-g8ed1b From abdadd3cfd3e7ea3da61ac774f84777d1f702058 Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Fri, 16 Mar 2018 00:00:55 +0100 Subject: net/sched: fix NULL dereference in the error path of tunnel_key_init() when the following command # tc action add action tunnel_key unset index 100 is run for the first time, and tunnel_key_init() fails to allocate struct tcf_tunnel_key_params, tunnel_key_release() dereferences NULL pointers. This causes the following error: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 IP: tunnel_key_release+0xd/0x40 [act_tunnel_key] PGD 8000000033787067 P4D 8000000033787067 PUD 74646067 PMD 0 Oops: 0000 [#1] SMP PTI Modules linked in: act_tunnel_key(E) act_csum ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 mbcache jbd2 crct10dif_pclmul crc32_pclmul snd_hda_codec_generic ghash_clmulni_intel snd_hda_intel pcbc snd_hda_codec snd_hda_core snd_hwdep snd_seq aesni_intel snd_seq_device crypto_simd glue_helper snd_pcm cryptd joydev snd_timer pcspkr virtio_balloon snd i2c_piix4 soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm virtio_net virtio_blk drm virtio_console crc32c_intel ata_piix serio_raw i2c_core virtio_pci libata virtio_ring virtio floppy dm_mirror dm_region_hash dm_log dm_mod CPU: 2 PID: 3101 Comm: tc Tainted: G E 4.16.0-rc4.act_vlan.orig+ #403 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:tunnel_key_release+0xd/0x40 [act_tunnel_key] RSP: 0018:ffffba46803b7768 EFLAGS: 00010286 RAX: ffffffffc09010a0 RBX: 0000000000000000 RCX: 0000000000000024 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff99ee336d7480 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000044 R10: 0000000000000220 R11: ffff99ee79d73131 R12: 0000000000000000 R13: ffff99ee32d67610 R14: ffff99ee7671dc38 R15: 00000000fffffff4 FS: 00007febcb2cd740(0000) GS:ffff99ee7fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 000000007c8e4005 CR4: 00000000001606e0 Call Trace: __tcf_idr_release+0x79/0xf0 tunnel_key_init+0xd9/0x460 [act_tunnel_key] tcf_action_init_1+0x2cc/0x430 tcf_action_init+0xd3/0x1b0 tc_ctl_action+0x18b/0x240 rtnetlink_rcv_msg+0x29c/0x310 ? _cond_resched+0x15/0x30 ? __kmalloc_node_track_caller+0x1b9/0x270 ? rtnl_calcit.isra.28+0x100/0x100 netlink_rcv_skb+0xd2/0x110 netlink_unicast+0x17c/0x230 netlink_sendmsg+0x2cd/0x3c0 sock_sendmsg+0x30/0x40 ___sys_sendmsg+0x27a/0x290 __sys_sendmsg+0x51/0x90 do_syscall_64+0x6e/0x1a0 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x7febca6deba0 RSP: 002b:00007ffe7b0dd128 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ffe7b0dd250 RCX: 00007febca6deba0 RDX: 0000000000000000 RSI: 00007ffe7b0dd1a0 RDI: 0000000000000003 RBP: 000000005aaa90cb R08: 0000000000000002 R09: 0000000000000000 R10: 00007ffe7b0dcba0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe7b0dd264 R14: 0000000000000001 R15: 0000000000669f60 Code: 44 00 00 8b 0d b5 23 00 00 48 8b 87 48 10 00 00 48 8b 3c c8 e9 a5 e5 d8 c3 0f 1f 44 00 00 0f 1f 44 00 00 53 48 8b 9f b0 00 00 00 <83> 7b 10 01 74 0b 48 89 df 31 f6 5b e9 f2 fa 7f c3 48 8b 7b 18 RIP: tunnel_key_release+0xd/0x40 [act_tunnel_key] RSP: ffffba46803b7768 CR2: 0000000000000010 Fix this in tunnel_key_release(), ensuring 'param' is not NULL before dereferencing it. Fixes: d0f6dd8a914f ("net/sched: Introduce act_tunnel_key") Signed-off-by: Davide Caratti Acked-by: Jiri Pirko Signed-off-by: David S. Miller --- net/sched/act_tunnel_key.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'net/sched/act_tunnel_key.c') diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c index fea772e66e62..1281ca463727 100644 --- a/net/sched/act_tunnel_key.c +++ b/net/sched/act_tunnel_key.c @@ -208,11 +208,12 @@ static void tunnel_key_release(struct tc_action *a) struct tcf_tunnel_key_params *params; params = rcu_dereference_protected(t->params, 1); + if (params) { + if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET) + dst_release(¶ms->tcft_enc_metadata->dst); - if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET) - dst_release(¶ms->tcft_enc_metadata->dst); - - kfree_rcu(params, rcu); + kfree_rcu(params, rcu); + } } static int tunnel_key_dump_addresses(struct sk_buff *skb, -- cgit v1.2.3-59-g8ed1b