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 0010
IP: tunnel_key_release+0xd/0x40 [act_tunnel_key]
PGD 800033787067 P4D 800033787067 PUD 74646067 PMD 0
Oops: [#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: GE4.16.0-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:ba46803b7768 EFLAGS: 00010286
RAX: c09010a0 RBX: RCX: 0024
RDX: RSI: RDI: 99ee336d7480
RBP: R08: 0001 R09: 0044
R10: 0220 R11: 99ee79d73131 R12:
R13: 99ee32d67610 R14: 99ee7671dc38 R15: fff4
FS: 7febcb2cd740() GS:99ee7fd0() knlGS:
CS: 0010 DS: ES: CR0: 80050033
CR2: 0010 CR3: 7c8e4005 CR4: 001606e0
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:7ffe7b0dd128 EFLAGS: 0246 ORIG_RAX: 002e
RAX: ffda RBX: 7ffe7b0dd250 RCX: 7febca6deba0
RDX: RSI: 7ffe7b0dd1a0 RDI: 0003
RBP: 5aaa90cb R08: 0002 R09:
R10: 7ffe7b0dcba0 R11: 0246 R12:
R13: 7ffe7b0dd264 R14: 0001 R15: 00669f60
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: ba46803b7768
CR2: 0010
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
---
net/sched/act_tunnel_key.c | 9 +
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c
index 0e23aac09ad6..5dd819840feb 100644
--- a/net/sched/act_tunnel_key.c
+++ b/net/sched/act_tunnel_key.c
@@ -207,11 +207,12 @@ 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(>tcft_enc_metadata->dst);
- if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET)
- dst_release(>tcft_enc_metadata->dst);
-
- kfree_rcu(params, rcu);
+ kfree_rcu(params, rcu);
+ }
}
static int tunnel_key_dump_addresses(struct sk_buff *skb,
--
2.14.3
