| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.9 34/46] net: openvswitch: ensure LSE is pullable before reading it | Date | Sun, 6 Dec 2020 12:17:42 +0100 |
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From: Davide Caratti <dcaratti@redhat.com>
[ Upstream commit 43c13605bad44b8abbc9776d6e63f62ccb7a47d6 ]
when openvswitch is configured 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.
Fixes: d27cf5c59a12 ("net: core: add MPLS update core helper and use in OvS") Signed-off-by: Davide Caratti <dcaratti@redhat.com> Link: https://lore.kernel.org/r/aa099f245d93218b84b5c056b67b6058ccf81a66.1606987185.git.dcaratti@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/openvswitch/actions.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/net/openvswitch/actions.c +++ b/net/openvswitch/actions.c @@ -200,6 +200,9 @@ static int set_mpls(struct sk_buff *skb, __be32 lse; int err; + if (!pskb_may_pull(skb, skb_network_offset(skb) + MPLS_HLEN)) + return -ENOMEM; + stack = mpls_hdr(skb); lse = OVS_MASKED(stack->label_stack_entry, *mpls_lse, *mask); err = skb_mpls_update_lse(skb, lse);
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