net/sched: cls_u32: Fix reference counter leak leading to overflow

stable inclusion
from stable-v5.10.185
commit af6eaa57986e82d7efd81984ee607927c6de61e4
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7N3N2
CVE: CVE-2023-3609

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=af6eaa57986e82d7efd81984ee607927c6de61e4



---------------------------

[ Upstream commit 04c55383 ]

In the event of a failure in tcf_change_indev(), u32_set_parms() will
immediately return without decrementing the recently incremented
reference counter.  If this happens enough times, the counter will
rollover and the reference freed, leading to a double free which can be
used to do 'bad things'.

In order to prevent this, move the point of possible failure above the
point where the reference counter is incremented.  Also save any
meaningful return values to be applied to the return data at the
appropriate point in time.

This issue was caught with KASAN.

Fixes: 705c7091 ("net: sched: cls_u32: no need to call tcf_exts_change for newly allocated struct")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Lu Wei <luwei32@huawei.com>