kconfig: fix possible buffer overflow

stable inclusion
from stable-v5.10.195
commit 84f99532152b2e8ccfa0d9ac4b98a9d6af487469
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I95JOC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=84f99532152b2e8ccfa0d9ac4b98a9d6af487469



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[ Upstream commit a3b7039b ]

Buffer 'new_argv' is accessed without bound check after accessing with
bound check via 'new_argc' index.

Fixes: e298f3b4 ("kconfig: add built-in function support")
Co-developed-by: Ivanov Mikhail <ivanov.mikhail1@huawei-partners.com>
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>