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| author | Cong Wang <xiyou.wangcong@gmail.com> | 2019-12-05 19:39:02 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-12-07 11:53:27 -0800 |
| commit | 0e4940928c26527ce8f97237fef4c8a91cd34207 (patch) | |
| tree | 7e7f865d29451d37511dd9171e61992fbad6f8d0 | |
| parent | 02a896ca84874bbfcedc006303f2951dda89b298 (diff) | |
| download | linux-0e4940928c26527ce8f97237fef4c8a91cd34207.tar.gz | |
gre: refetch erspan header from skb->data after pskb_may_pull()
After pskb_may_pull() we should always refetch the header
pointers from the skb->data in case it got reallocated.
In gre_parse_header(), the erspan header is still fetched
from the 'options' pointer which is fetched before
pskb_may_pull().
Found this during code review of a KMSAN bug report.
Fixes: cb73ee40b1b3 ("net: ip_gre: use erspan key field for tunnel lookup")
Cc: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Acked-by: William Tu <u9012063@gmail.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/gre_demux.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c index 44bfeecac33e..5fd6e8ed02b5 100644 --- a/net/ipv4/gre_demux.c +++ b/net/ipv4/gre_demux.c @@ -127,7 +127,7 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, if (!pskb_may_pull(skb, nhs + hdr_len + sizeof(*ershdr))) return -EINVAL; - ershdr = (struct erspan_base_hdr *)options; + ershdr = (struct erspan_base_hdr *)(skb->data + nhs + hdr_len); tpi->key = cpu_to_be32(get_session_id(ershdr)); } |