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| author | Davide Caratti <dcaratti@redhat.com> | 2020-12-03 10:37:52 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-08 10:40:27 +0100 |
| commit | 8f92330b08735e9a75ef1a8f6721c8ac51d03afb (patch) | |
| tree | a00aa471e690ddf6b1f6aed2d80908b236c6706e | |
| parent | 1086f789060ab968314b93ddbee91547f276b5d9 (diff) | |
| download | linux-stable-8f92330b08735e9a75ef1a8f6721c8ac51d03afb.tar.gz linux-stable-8f92330b08735e9a75ef1a8f6721c8ac51d03afb.tar.bz2 linux-stable-8f92330b08735e9a75ef1a8f6721c8ac51d03afb.zip | |
net/sched: act_mpls: ensure LSE is pullable before reading it
[ Upstream commit 9608fa653059c3f72faab0c148ac8773c46e7314 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 7954021ade33..0fccae356dc1 100644 --- a/net/sched/act_mpls.c +++ b/net/sched/act_mpls.c @@ -88,6 +88,9 @@ 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; |