| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 076/105] net: rtnetlink: fix info leak in RTM_GETSTATS call | Date | Tue, 10 Oct 2017 21:50:47 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
[ Upstream commit ce024f42c2e28b6bce4ecc1e891b42f57f753892 ]
When RTM_GETSTATS was added the fields of its header struct were not all initialized when returning the result thus leaking 4 bytes of information to user-space per rtnl_fill_statsinfo call, so initialize them now. Thanks to Alexander Potapenko for the detailed report and bisection.
Reported-by: Alexander Potapenko <glider@google.com> Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/core/rtnetlink.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3758,6 +3758,9 @@ static int rtnl_fill_statsinfo(struct sk return -EMSGSIZE; ifsm = nlmsg_data(nlh); + ifsm->family = PF_UNSPEC; + ifsm->pad1 = 0; + ifsm->pad2 = 0; ifsm->ifindex = dev->ifindex; ifsm->filter_mask = filter_mask;
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