On Sun, May 19, 2019 at 10:27:53PM +0200, Florian Westphal wrote:
> Nathan Chancellor <natechancellor@xxxxxxxxx> wrote:
> > On Wed, May 15, 2019 at 12:56:16PM +0200, Greg Kroah-Hartman wrote:
> > > From: Hangbin Liu <liuhangbin@xxxxxxxxx>
> > >
> > > [ Upstream commit e9919a24d3022f72bcadc407e73a6ef17093a849 ]
>
> [..]
>
> > > Fixes: 153380ec4b9 ("fib_rules: Added NLM_F_EXCL support to fib_nl_newrule")
> > > Reported-by: Thomas Haller <thaller@xxxxxxxxxx>
> > > Signed-off-by: Hangbin Liu <liuhangbin@xxxxxxxxx>
> > > Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > ---
> > > net/core/fib_rules.c | 6 +++---
> > > 1 file changed, 3 insertions(+), 3 deletions(-)
> > >
> > > --- a/net/core/fib_rules.c
> > > +++ b/net/core/fib_rules.c
> > > @@ -429,9 +429,9 @@ int fib_nl_newrule(struct sk_buff *skb,
> > > if (rule->l3mdev && rule->table)
> > > goto errout_free;
> > >
> > > - if ((nlh->nlmsg_flags & NLM_F_EXCL) &&
> > > - rule_exists(ops, frh, tb, rule)) {
> > > - err = -EEXIST;
> > > + if (rule_exists(ops, frh, tb, rule)) {
> > > + if (nlh->nlmsg_flags & NLM_F_EXCL)
> > > + err = -EEXIST;
> > This commit is causing issues on Android devices when Wi-Fi and mobile
> > data are both enabled. The device will do a soft reboot consistently.
>
> Not surprising, the patch can't be applied to 4.9 as-is.
>
> In 4.9, code looks like this:
>
> err = -EINVAL;
> /* irrelevant */
> if (rule_exists(ops, frh, tb, rule)) {
> if (nlh->nlmsg_flags & NLM_F_EXCL)
> err = -EEXIST;
> goto errout_free;
> }
>
> So, if rule_exists() is true, we return -EINVAL to caller
> instead of 0, unlike upstream.
>
> I don't think this commit is stable material.
Thanks Florian for helping check it. So we need either revert this patch,
or at least backport adeb45cbb505 ("fib_rules: fix error return code") and
f9d4b0c1e969 ("fib_rules: move common handling of newrule delrule
msgs into fib_nl2rule").
For me, I agree to revert this patch from stable tree as it's a small fix. The
issue has been there for a long time and I didn't see much complain from
customer.
Thanks
Hangbin
