Browse Source

base-files: functions.sh: fix config_get() on invalid identifiers

When passing a section or option value to config_get() which contains
characters that happen to be valid variable interpolation expressions,
the function returns a nonsensical expression result instead of the
expected empty string.

When the passed section or option name contains other characters which
are not valid within a shell variable name, a substitution error is
occuring instead.

The issue can be easily reproduced by one of the following examples:

    root@OpenWrt:~# . /lib/functions.sh
    root@OpenWrt:~# config load system
    root@OpenWrt:~# config_get variable invalid-section option
    root@OpenWrt:~# echo "$variable"
    section_option:-

    root@OpenWrt:~# . /lib/functions.sh
    root@OpenWrt:~# config load system
    root@OpenWrt:~# config_get variable section invalid-option
    root@OpenWrt:~# echo "$variable"
    option:-

    root@OpenWrt:~# . /lib/functions.sh
    root@OpenWrt:~# config load system
    root@OpenWrt:~# config_get variable section invalid@option
    -ash: eval: syntax error: bad substitution

Fix this issue by only performing interpolations when the given section
and option arguments are free of illegal characters.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
master
Jo-Philipp Wich 2 years ago
parent
commit
4a6795409d
  1. 2
      package/base-files/Makefile
  2. 11
      package/base-files/files/lib/functions.sh

2
package/base-files/Makefile

@ -12,7 +12,7 @@ include $(INCLUDE_DIR)/version.mk
include $(INCLUDE_DIR)/feeds.mk
PKG_NAME:=base-files
PKG_RELEASE:=225
PKG_RELEASE:=226
PKG_FLAGS:=nonshared
PKG_FILE_DEPENDS:=$(PLATFORM_DIR)/ $(GENERIC_PLATFORM_DIR)/base-files/

11
package/base-files/files/lib/functions.sh

@ -107,9 +107,14 @@ config_unset() {
# config_get <variable> <section> <option> [<default>]
# config_get <section> <option>
config_get() {
case "$3" in
"") eval echo "\"\${CONFIG_${1}_${2}:-\${4}}\"";;
*) eval export ${NO_EXPORT:+-n} -- "${1}=\${CONFIG_${2}_${3}:-\${4}}";;
case "$2${3:-$1}" in
*[^A-Za-z0-9_]*) : ;;
*)
case "$3" in
"") eval echo "\"\${CONFIG_${1}_${2}:-\${4}}\"";;
*) eval export ${NO_EXPORT:+-n} -- "${1}=\${CONFIG_${2}_${3}:-\${4}}";;
esac
;;
esac
}

Loading…
Cancel
Save