[PATCH iproute2 0/2] fix "ip link show dev ..." for NICs with many VFs

From: Michal Kubecek
Date: Fri Sep 01 2017 - 12:39:13 EST


Two of our customers recently encountered problems with processing of large
messages produced by kernel in response to "ip link show" for NICs with
many (120-128) virtual functions. While some of them have been already
addressed in recent versions of iproute2, some still persist.

Patch 1 adds check to handle the case when a message fits into the
buffer in rtnl_talk() but not into the buffer in iplink_get().

Patch 2 increases the buffer size in iplink_get() to suffice even for
NICs with 128 VFs.

Note: after applying patch 2, patch 1 seems useless as both buffers have
the same size so that the check cannot actually trigger. However, as we
cannot guarantee they will always stay the same, I believe the check
should still be added.

Michal Kubecek (2):
iplink: check for message truncation in iplink_get()
iplink: double the buffer size also in iplink_get()

ip/iplink.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

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2.14.1