xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net/sched: fix corrupted L2 header with MPLS 'push' and 'pop' actions

Browse Source 
the following script:

 # tc qdisc add dev eth0 clsact
 # tc filter add dev eth0 egress protocol ip matchall \
 > action mpls push protocol mpls_uc label 0x355aa bos 1

causes corruption of all IP packets transmitted by eth0. On TC egress, we
can't rely on the value of skb->mac_len, because it's 0 and a MPLS 'push'
operation will result in an overwrite of the first 4 octets in the packet
L2 header (e.g. the Destination Address if eth0 is an Ethernet); the same
error pattern is present also in the MPLS 'pop' operation. Fix this error
in act_mpls data plane, computing 'mac_len' as the difference between the
network header and the mac header (when not at TC ingress), and use it in
MPLS 'push'/'pop' core functions.

v2: unbreak 'make htmldocs' because of missing documentation of 'mac_len'
    in skb_mpls_pop(), reported by kbuild test robot

CC: Lorenzo Bianconi <lorenzo@kernel.org>
Fixes: 2a2ea50870 ("net: sched: add mpls manipulation actions to TC")
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Acked-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Davide Caratti
2019-10-12 13:55:07 +02:00
committed by David S. Miller
parent dedc5a08da
commit fa4e0f8855
4 changed files with 25 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files

5
include/linux/skbuff.h
View File

@@ -3510,8 +3510,9 @@ int skb_ensure_writable(struct sk_buff *skb, int write_len);
int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci);
int skb_vlan_pop(struct sk_buff *skb);
int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci);
int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto);
int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto);
int skb_mpls_push(struct sk_buff *skb, __be32 mpls_lse, __be16 mpls_proto,
int mac_len);
int skb_mpls_pop(struct sk_buff *skb, __be16 next_proto, int mac_len);
int skb_mpls_update_lse(struct sk_buff *skb, __be32 mpls_lse);
int skb_mpls_dec_ttl(struct sk_buff *skb);
struct sk_buff *pskb_extract(struct sk_buff *skb, int off, int to_copy,