In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/sbin/ifup line 7:

	local interface="$1"

        ^-------------^ SC3043 (warning): In POSIX sh, 'local' is undefined.

In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/sbin/ifup line 9:

		ubus call network.interface $mode "{ \"interface\" : \"$interface\" }"

                                            ^---^ SC2086 (info): Double quote to prevent globbing and word splitting.

Did you mean: 

		ubus call network.interface "$mode" "{ \"interface\" : \"$interface\" }"

In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/sbin/ifup line 40:

	for interface in `ubus -S list 'network.interface.*'`; do

                         ^-- SC2006 (style): Use $(...) notation instead of legacy backticks `...`.

Did you mean: 

	for interface in $(ubus -S list 'network.interface.*'); do

In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/sbin/ifup line 54:

	. /lib/functions.sh

          ^---------------^ SC1091 (info): Not following: /lib/functions.sh was not specified as input (see shellcheck -x).

In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/sbin/ifup line 57:

		local wdev wnet

                ^-------------^ SC3043 (warning): In POSIX sh, 'local' is undefined.

In /logs/firmware/unblob_extracted/firmware_extract/1568982-13971496.squashfs_v4_le_extract/sbin/ifup line 74:

	for dev in $(echo "$radio_devs" | sort -u); do

                           ^---------^ SC2154 (warning): radio_devs is referenced but not assigned.

For more information:

  https://www.shellcheck.net/wiki/SC2154 -- radio_devs is referenced but not ...

  https://www.shellcheck.net/wiki/SC3043 -- In POSIX sh, 'local' is undefined.

  https://www.shellcheck.net/wiki/SC1091 -- Not following: /lib/functions.sh ...