Reject invalid quoted strings

String which ended in an unfinished quote were accepted, potentially
with bad memory accesses.

Reject anything which ends in a unfished quote, or contains
non-whitespace characters right after the closing quote.

_FOREACH_WORD now returns the invalid character in *state. But this return
value is not checked anywhere yet.

Also, make 'word' and 'state' variables const pointers, and rename 'w'
to 'word' in various places. Things are easier to read if the same name
is used consistently.

mbiebl_> am I correct that something like this doesn't work
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-passwd "Unlock EncFS"'
mbiebl_> systemd seems to strip of the quotes
mbiebl_> systemctl status shows
mbiebl_> ExecStart=/usr/bin/encfs --extpass='/bin/systemd-ask-password Unlock EncFS  $RootDir $MountPoint
mbiebl_> which is pretty weird

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/src/libudev/util.h b/src/libudev/util.h
index a38e8e61c5..15a11cc537 100644
--- a/src/libudev/util.h
+++ b/src/libudev/util.h
@@ -134,11 +134,13 @@ int safe_atoi(const char *s, int *ret_i);
 int safe_atollu(const char *s, unsigned long long *ret_u);
 int safe_atolli(const char *s, long long int *ret_i);
 
-char *split(const char *c, size_t *l, const char *separator, char **state);
-char *split_quoted(const char *c, size_t *l, char **state);
+const char* split(const char **state, size_t *l, const char *separator, bool quoted);
 
 #define FOREACH_WORD_QUOTED(word, length, s, state)                     \
-        for ((state) = NULL, (word) = split_quoted((s), &(length), &(state)); (word); (word) = split_quoted((s), &(length), &(state)))
+        _FOREACH_WORD(word, length, s, WHITESPACE, true, state)
+
+#define _FOREACH_WORD(word, length, s, separator, quoted, state)        \
+        for ((state) = (s), (word) = split(&(state), &(length), (separator), (quoted)); (word); (word) = split(&(state), &(length), (separator), (quoted)))
 
 char *strappend(const char *s, const char *suffix);
 char *strnappend(const char *s, const char *suffix, size_t length);