2020-02-15 00:56:14

by Michal Kubecek

Subject: [PATCH net] ethtool: fix application of verbose no_mask bitset

A bitset without mask in a _SET request means we want exactly the bits in
the bitset to be set. This works correctly for compact format but when
verbose format is parsed, ethnl_update_bitset32_verbose() only sets the
bits present in the request bitset but does not clear the rest. This can
cause incorrect results like

lion:~ # ethtool eth0 | grep Wake
Supports Wake-on: pumbg
Wake-on: g
lion:~ # ethtool -s eth0 wol u
lion:~ # ethtool eth0 | grep Wake
Supports Wake-on: pumbg
Wake-on: ug

when the second ethtool command issues request

ETHTOOL_MSG_WOL_SET
ETHTOOL_A_WOL_HEADER
ETHTOOL_A_HEADER_DEV_NAME = "eth0"
ETHTOOL_A_WOL_MODES
ETHTOOL_A_BITSET_NOMASK
ETHTOOL_A_BITSET_BITS
ETHTOOL_A_BITSET_BITS_BIT
ETHTOOL_BITSET_BIT_INDEX = 1

Fix the logic by clearing the whole target bitmap before we start iterating
through the request bits.

Fixes: 10b518d4e6dd ("ethtool: netlink bitset handling")
Signed-off-by: Michal Kubecek <[email protected]>
---
net/ethtool/bitset.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/ethtool/bitset.c b/net/ethtool/bitset.c
index fce45dac4205..8977fe1f3946 100644
--- a/net/ethtool/bitset.c
+++ b/net/ethtool/bitset.c
@@ -447,7 +447,10 @@ ethnl_update_bitset32_verbose(u32 *bitmap, unsigned int nbits,
"mask only allowed in compact bitset");
return -EINVAL;
}
+
no_mask = tb[ETHTOOL_A_BITSET_NOMASK];
+ if (no_mask)
+ ethnl_bitmap32_clear(bitmap, 0, nbits, mod);

nla_for_each_nested(bit_attr, tb[ETHTOOL_A_BITSET_BITS], rem) {
bool old_val, new_val;
--
2.25.0

2020-02-17 03:30:49

by David Miller

Subject: Re: [PATCH net] ethtool: fix application of verbose no_mask bitset

From: Michal Kubecek <[email protected]>
Date: Sat, 15 Feb 2020 01:55:53 +0100 (CET)

> A bitset without mask in a _SET request means we want exactly the bits in
> the bitset to be set. This works correctly for compact format but when
> verbose format is parsed, ethnl_update_bitset32_verbose() only sets the
> bits present in the request bitset but does not clear the rest. This can
> cause incorrect results like
>
> lion:~ # ethtool eth0 | grep Wake
> Supports Wake-on: pumbg
> Wake-on: g
> lion:~ # ethtool -s eth0 wol u
> lion:~ # ethtool eth0 | grep Wake
> Supports Wake-on: pumbg
> Wake-on: ug
>
> when the second ethtool command issues request
>
> ETHTOOL_MSG_WOL_SET
> ETHTOOL_A_WOL_HEADER
> ETHTOOL_A_HEADER_DEV_NAME = "eth0"
> ETHTOOL_A_WOL_MODES
> ETHTOOL_A_BITSET_NOMASK
> ETHTOOL_A_BITSET_BITS
> ETHTOOL_A_BITSET_BITS_BIT
> ETHTOOL_BITSET_BIT_INDEX = 1
>
> Fix the logic by clearing the whole target bitmap before we start iterating
> through the request bits.
>
> Fixes: 10b518d4e6dd ("ethtool: netlink bitset handling")
> Signed-off-by: Michal Kubecek <[email protected]>

Applied, thanks Michal.