On 27/08/2020 10:23, Michal Kubecek wrote: > On Mon, Aug 24, 2020 at 08:46:30AM +0200, Hans-Christian Noren Egtvedt wrote: >> In commit bef780467fa ('ioctl: do not pass transceiver value back to >> kernel') a regression slipped. If we have a kernel that does not support >> the ETHTOOL_xLINKSETTINGS API, then the do_ioctl_glinksettings() >> function will return a NULL pointer. >> >> Hence before memset'ing the pointer to zero we must first check it is >> valid, as NULL return is perfectly fine when running on old kernels. >> > > Please add a standard "Fixes:" line here, i.e. > > Fixes: bef780467fa7 ("ioctl: do not pass transceiver value back to kernel") > >> Signed-off-by: Hans-Christian Noren Egtvedt <hegtv...@cisco.com> >> --- >> ethtool.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/ethtool.c b/ethtool.c >> index c4ad186..8267d6b 100644 >> --- a/ethtool.c >> +++ b/ethtool.c >> @@ -2908,8 +2908,10 @@ static int do_sset(struct cmd_context *ctx) >> struct ethtool_link_usettings *link_usettings; >> >> link_usettings = do_ioctl_glinksettings(ctx); >> - memset(&link_usettings->deprecated, 0, >> - sizeof(link_usettings->deprecated)); >> + if (link_usettings) { >> + memset(&link_usettings->deprecated, 0, >> + sizeof(link_usettings->deprecated)); >> + } >> if (link_usettings == NULL) >> link_usettings = do_ioctl_gset(ctx); > > This is correct fix but now we have two if statements with exactly > opposite conditions here; please combine them into one if-else.
Thank you for the review, a v2 will arrive shortly.