net: dsa: sja1105: fix buffer overflow in sja1105_setup_devlink_regions()

stable inclusion
from stable-v5.10.138
commit 7983e1e44cb322eba6af84160b6d18df80603fb8
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60QFD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7983e1e44cb322eba6af84160b6d18df80603fb8



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commit fd8e899c upstream.

If an error occurs in dsa_devlink_region_create(), then 'priv->regions'
array will be accessed by negative index '-1'.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Rustam Subkhankulov <subkhankulov@ispras.ru>
Fixes: bf425b82 ("net: dsa: sja1105: expose static config as devlink region")
Link: https://lore.kernel.org/r/20220817003845.389644-1-subkhankulov@ispras.ru


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>