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xargs: fix handling of quoted arguments, closes 11441

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As reported in bug 11441 when presented with a large number of quoted
arguments xargs can return 'argument line too long':

   seq 10000 29999 | sed -e 's/^/"/' -e 's/$/"/' | busybox xargs echo

This happens because the variant of process_stdin() which handles quoted
arguments doesn't preserve state between calls.  If the allowed number
of characters is exceeded part way through a quoted argument the next
call to process_stdin() incorrectly treats the terminating quote as a
starting quote, thus quoting all of the argument separators.

function                                             old     new   delta
process_stdin                                        274     303     +29
xargs_main                                           731     745     +14
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 43/0)               Total: 43 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Ron Yorston 2020-01-24 13:16:45 +00:00 committed by Denys Vlasenko
parent 16bcd504a3
commit 1ff7002b1d
2 changed files with 27 additions and 9 deletions
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27
findutils/xargs.c
View File

@ -114,17 +114,28 @@ struct globals {
int max_procs;
#endif
smalluint xargs_exitcode;
#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
#define NORM 0
#define QUOTE 1
#define BACKSLASH 2
#define SPACE 4
smalluint process_stdin__state;
char process_stdin__q;
#endif
} FIX_ALIASING;
#define G (*(struct globals*)bb_common_bufsiz1)
#define INIT_G() do { \
setup_common_bufsiz(); \
G.eof_str = NULL; /* need to clear by hand because we are NOEXEC applet */ \
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.repl_str = "{}";) \
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.eol_ch = '\n';) \
/* Even zero values are set because we are NOEXEC applet */ \
G.eof_str = NULL; \
G.idx = 0; \
IF_FEATURE_XARGS_SUPPORT_PARALLEL(G.running_procs = 0;) \
IF_FEATURE_XARGS_SUPPORT_PARALLEL(G.max_procs = 1;) \
G.xargs_exitcode = 0; \
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.repl_str = "{}";) \
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.eol_ch = '\n';) \
IF_FEATURE_XARGS_SUPPORT_QUOTES(G.process_stdin__state = NORM;) \
IF_FEATURE_XARGS_SUPPORT_QUOTES(G.process_stdin__q = '\0';) \
} while (0)
@ -257,12 +268,8 @@ static void store_param(char *s)
#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
{
#define NORM 0
#define QUOTE 1
#define BACKSLASH 2
#define SPACE 4
char q = '\0'; /* quote char */
char state = NORM;
#define q G.process_stdin__q
#define state G.process_stdin__state
char *s = buf; /* start of the word */
char *p = s + strlen(buf); /* end of the word */
@ -339,6 +346,8 @@ static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
/* store_param(NULL) - caller will do it */
dbg_msg("return:'%s'", s);
return s;
#undef q
#undef state
}
#else
/* The variant does not support single quotes, double quotes or backslash */

9
testsuite/xargs.tests
View File

@ -41,4 +41,13 @@ testing "xargs -sNUM test 2" \
"echo 1 2 3 4 5 6 7 8 9 0\n""echo 1 2 3 4 5 6 7 8 9\n""echo 1 00\n" \
"" "2 3 4 5 6 7 8 9 0 2 3 4 5 6 7 8 9 00\n"
# see that we don't get "argument line too long",
# but do see the last word, 99999, instead
optional FEATURE_XARGS_SUPPORT_QUOTES
testing "xargs argument line too long" \
"seq 10000 99999 | sed -e 's/^/\"/' -e 's/$/\"/' | xargs echo | grep -o 99999; echo \$?" \
"99999\n0\n" \
"" ""
SKIP=
exit $FAILCOUNT