of: Fix double free in of_parse_phandle_with_args_map

stable inclusion
from stable-v4.19.306
commit 26b4d702c44f9e5cf3c5c001ae619a4a001889db
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I970CO


CVE: NA

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

[ Upstream commit 4dde83569832f9377362e50f7748463340c5db6b ]

In of_parse_phandle_with_args_map() the inner loop that
iterates through the map entries calls of_node_put(new)
to free the reference acquired by the previous iteration
of the inner loop. This assumes that the value of "new" is
NULL on the first iteration of the inner loop.

Make sure that this is true in all iterations of the outer
loop by setting "new" to NULL after its value is assigned to "cur".

Extend the unittest to detect the double free and add an additional
test case that actually triggers this path.

Fixes: bd6f2fd5 ("of: Support parsing phandle argument lists through a nexus node")
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: "Christian A. Ehrhardt" <lk@c--e.de>
Link: https://lore.kernel.org/r/20231229105411.1603434-1-lk@c--e.de


Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>