linux-toradex.git/net/core/rtnetlink.c, branch v3.2.62

rtnetlink: fix userspace API breakage for iproute2 < v3.9.0

2014-08-06T17:07:39+00:00

commit e5eca6d41f53db48edd8cf88a3f59d2c30227f8e upstream.

When running RHEL6 userspace on a current upstream kernel, "ip link"
fails to show VF information.

The reason is a kernel<->userspace API change introduced by commit
88c5b5ce5cb57 ("rtnetlink: Call nlmsg_parse() with correct header length"),
after which the kernel does not see iproute2's IFLA_EXT_MASK attribute
in the netlink request.

iproute2 adjusted for the API change in its commit 63338dca4513
("libnetlink: Use ifinfomsg instead of rtgenmsg in rtnl_wilddump_req_filter").

The problem has been noticed before:
http://marc.info/?l=linux-netdev&m=136692296022182&w=2
(Subject: Re: getting VF link info seems to be broken in 3.9-rc8)

We can do better than tell those with old userspace to upgrade. We can
recognize the old iproute2 in the kernel by checking the netlink message
length. Even when including the IFLA_EXT_MASK attribute, its netlink
message is shorter than struct ifinfomsg.

With this patch "ip link" shows VF information in both old and new
iproute2 versions.

Signed-off-by: Michal Schmidt 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

rtnetlink: Only supply IFLA_VF_PORTS information when RTEXT_FILTER_VF is set

2014-06-09T12:28:57+00:00

[ Upstream commit c53864fd60227de025cb79e05493b13f69843971 ]

Since 115c9b81928360d769a76c632bae62d15206a94a (rtnetlink: Fix problem with
buffer allocation), RTM_NEWLINK messages only contain the IFLA_VFINFO_LIST
attribute if they were solicited by a GETLINK message containing an
IFLA_EXT_MASK attribute with the RTEXT_FILTER_VF flag.

That was done because some user programs broke when they received more data
than expected - because IFLA_VFINFO_LIST contains information for each VF
it can become large if there are many VFs.

However, the IFLA_VF_PORTS attribute, supplied for devices which implement
ndo_get_vf_port (currently the 'enic' driver only), has the same problem.
It supplies per-VF information and can therefore become large, but it is
not currently conditional on the IFLA_EXT_MASK value.

Worse, it interacts badly with the existing EXT_MASK handling.  When
IFLA_EXT_MASK is not supplied, the buffer for netlink replies is fixed at
NLMSG_GOODSIZE.  If the information for IFLA_VF_PORTS exceeds this, then
rtnl_fill_ifinfo() returns -EMSGSIZE on the first message in a packet.
netlink_dump() will misinterpret this as having finished the listing and
omit data for this interface and all subsequent ones.  That can cause
getifaddrs(3) to enter an infinite loop.

This patch addresses the problem by only supplying IFLA_VF_PORTS when
IFLA_EXT_MASK is supplied with the RTEXT_FILTER_VF flag set.

Signed-off-by: David Gibson 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

rtnetlink: Warn when interface's information won't fit in our packet

2014-06-09T12:28:57+00:00

[ Upstream commit 973462bbde79bb827824c73b59027a0aed5c9ca6 ]

Without IFLA_EXT_MASK specified, the information reported for a single
interface in response to RTM_GETLINK is expected to fit within a netlink
packet of NLMSG_GOODSIZE.

If it doesn't, however, things will go badly wrong,  When listing all
interfaces, netlink_dump() will incorrectly treat -EMSGSIZE on the first
message in a packet as the end of the listing and omit information for
that interface and all subsequent ones.  This can cause getifaddrs(3) to
enter an infinite loop.

This patch won't fix the problem, but it will WARN_ON() making it easier to
track down what's going wrong.

Signed-off-by: David Gibson 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

rtnetlink: Call nlmsg_parse() with correct header length

2013-05-13T14:02:37+00:00

[ Upstream commit 88c5b5ce5cb57af6ca2a7cf4d5715fa320448ff9 ]

Signed-off-by: Michael Riesch 
Cc: "David S. Miller" 
Cc: Greg Kroah-Hartman 
Cc: Jiri Benc 
Cc: "Theodore Ts'o" 
Cc: linux-kernel@vger.kernel.org
Acked-by: Mark Rustad 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

rtnetlink: Mask the rta_type when range checking

2013-03-27T02:41:07+00:00

[ Upstream commit a5b8db91442fce9c9713fcd656c3698f1adde1d6 ]

Range/validity checks on rta_type in rtnetlink_rcv_msg() do
not account for flags that may be set.  This causes the function
to return -EINVAL when flags are set on the type (for example
NLA_F_NESTED).

Signed-off-by: Vlad Yasevich 
Acked-by: Thomas Graf 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

rtnl: fix info leak on RTM_GETLINK request for VF devices

2013-03-27T02:40:58+00:00

[ Upstream commit 84d73cd3fb142bf1298a8c13fd4ca50fd2432372 ]

Initialize the mac address buffer with 0 as the driver specific function
will probably not fill the whole buffer. In fact, all in-kernel drivers
fill only ETH_ALEN of the MAX_ADDR_LEN bytes, i.e. 6 of the 32 possible
bytes. Therefore we currently leak 26 bytes of stack memory to userland
via the netlink interface.

Signed-off-by: Mathias Krause 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

rtnetlink: fix rtnl_calcit() and rtnl_dump_ifinfo()

2012-11-16T16:46:52+00:00

commit a4b64fbe482c7766f7925f03067fc637716bfa3f upstream.

nlmsg_parse() might return an error, so test its return value before
potential random memory accesses.

Errors introduced in commit 115c9b81928 (rtnetlink: Fix problem with
buffer allocation)

Signed-off-by: Eric Dumazet 
Cc: Greg Rose 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

rtnetlink: Fix problem with buffer allocation

2012-11-16T16:46:52+00:00

commit 115c9b81928360d769a76c632bae62d15206a94a upstream.

Implement a new netlink attribute type IFLA_EXT_MASK.  The mask
is a 32 bit value that can be used to indicate to the kernel that
certain extended ifinfo values are requested by the user application.
At this time the only mask value defined is RTEXT_FILTER_VF to
indicate that the user wants the ifinfo dump to send information
about the VFs belonging to the interface.

This patch fixes a bug in which certain applications do not have
large enough buffers to accommodate the extra information returned
by the kernel with large numbers of SR-IOV virtual functions.
Those applications will not send the new netlink attribute with
the interface info dump request netlink messages so they will
not get unexpectedly large request buffers returned by the kernel.

Modifies the rtnl_calcit function to traverse the list of net
devices and compute the minimum buffer size that can hold the
info dumps of all matching devices based upon the filter passed
in via the new netlink attribute filter mask.  If no filter
mask is sent then the buffer allocation defaults to NLMSG_GOODSIZE.

With this change it is possible to add yet to be defined netlink
attributes to the dump request which should make it fairly extensible
in the future.

Signed-off-by: Greg Rose 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: drop the change in do_setlink() that reverts
 commit f18da14565819ba43b8321237e2426a2914cc2ef, which we never applied]
Signed-off-by: Ben Hutchings

net: fix rtnetlink IFF_PROMISC and IFF_ALLMULTI handling

2012-08-19T17:15:25+00:00

[ Upstream commit b1beb681cba5358f62e6187340660ade226a5fcc ]

When device flags are set using rtnetlink, IFF_PROMISC and IFF_ALLMULTI
flags are handled specially. Function dev_change_flags sets IFF_PROMISC and
IFF_ALLMULTI bits in dev->gflags according to the passed value but
do_setlink passes a result of rtnl_dev_combine_flags which takes those bits
from dev->flags.

This can be easily trigerred by doing:

tcpdump -i eth0 &
ip l s up eth0

ip sets IFF_UP flag in ifi_flags and ifi_change, which is combined with
IFF_PROMISC by rtnl_dev_combine_flags, causing __dev_change_flags to set
IFF_PROMISC in gflags.

Reported-by: Max Matveev 
Signed-off-by: Jiri Benc 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: feed /dev/random with the MAC address when registering a device

2012-08-09T23:24:44+00:00

commit 7bf2357524408b97fec58344caf7397f8140c3fd upstream.

Cc: David Miller 
Cc: Linus Torvalds 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Ben Hutchings