diff options
| author | Davide Caratti | 2020-12-03 10:37:52 +0100 |
|---|---|---|
| committer | Jakub Kicinski | 2020-12-03 11:13:37 -0800 |
| commit | 9608fa653059c3f72faab0c148ac8773c46e7314 (patch) | |
| tree | 6ba66312b3eaa2d0439d397a6527ee5a3daccfe1 | |
| parent | 43c13605bad44b8abbc9776d6e63f62ccb7a47d6 (diff) | |
net/sched: act_mpls: ensure LSE is pullable before reading it
when 'act_mpls' is used to mangle the LSE, the current value is read from
the packet dereferencing 4 bytes at mpls_hdr(): ensure that the label is
contained in the skb "linear" area.
Found by code inspection.
v2:
- use MPLS_HLEN instead of sizeof(new_lse), thanks to Jakub Kicinski
Fixes: 2a2ea50870ba ("net: sched: add mpls manipulation actions to TC")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/3243506cba43d14858f3bd21ee0994160e44d64a.1606987058.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/sched/act_mpls.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/sched/act_mpls.c b/net/sched/act_mpls.c index 5c7456e5b5cf..d1486ea496a2 100644 --- a/net/sched/act_mpls.c +++ b/net/sched/act_mpls.c @@ -105,6 +105,9 @@ static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a, goto drop; break; case TCA_MPLS_ACT_MODIFY: + if (!pskb_may_pull(skb, + skb_network_offset(skb) + MPLS_HLEN)) + goto drop; new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false); if (skb_mpls_update_lse(skb, new_lse)) goto drop; |