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authorDenys Vlasenko <vda.linux@googlemail.com>2019-01-08 18:08:48 +0100
committerDenys Vlasenko <vda.linux@googlemail.com>2019-01-08 18:10:00 +0100
commitfc7aa7a296cf13d13aae5457f4f7cd2b73700234 (patch)
tree322b3d74f6664b18ed29b72a251e16783cf99e5c /miscutils
parentce51140664d82300d25b096b4a41f01fdfd766b3 (diff)
downloadbusybox-fc7aa7a296cf13d13aae5457f4f7cd2b73700234.tar.gz
bc: disallow invalid syntax like "{ print 1 print 2 }"
statement parsing must NOT eat the terminator: caller needs to know what it was, to correctly decide whether it is a valid one. function old new delta zxc_program_read - 234 +234 zdc_program_printStream - 144 +144 zbc_parse_stmt_possibly_auto 1413 1460 +47 zxc_vm_process 869 859 -10 zxc_program_exec 4116 4101 -15 zdc_program_asciify 368 - -368 ------------------------------------------------------------------------------ (add/remove: 2/1 grow/shrink: 1/2 up/down: 425/-393) Total: 32 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'miscutils')
-rw-r--r--miscutils/bc.c36
1 files changed, 21 insertions, 15 deletions
diff --git a/miscutils/bc.c b/miscutils/bc.c
index bf174dafb..faf6226e1 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -4554,11 +4554,11 @@ static BC_STATUS zbc_parse_stmt_possibly_auto(bool auto_allowed)
if (p->lex == XC_LEX_NLINE) {
dbg_lex_done("%s:%d done (seen XC_LEX_NLINE)", __func__, __LINE__);
- RETURN_STATUS(zxc_lex_next());
+ RETURN_STATUS(s);
}
if (p->lex == BC_LEX_SCOLON) {
dbg_lex_done("%s:%d done (seen BC_LEX_SCOLON)", __func__, __LINE__);
- RETURN_STATUS(zxc_lex_next());
+ RETURN_STATUS(s);
}
if (p->lex == BC_LEX_LBRACE) {
@@ -4574,9 +4574,19 @@ static BC_STATUS zbc_parse_stmt_possibly_auto(bool auto_allowed)
}
while (p->lex != BC_LEX_RBRACE) {
dbg_lex("%s:%d block parsing loop", __func__, __LINE__);
-//FIXME: prevent wrong syntax such as "{ print 1 print 2 }"
s = zbc_parse_stmt();
if (s) RETURN_STATUS(s);
+ // Check that next token is a correct stmt delimiter -
+ // disallows "print 1 print 2" and such.
+ if (p->lex == BC_LEX_RBRACE)
+ break;
+ if (p->lex != BC_LEX_SCOLON
+ && p->lex != XC_LEX_NLINE
+ ) {
+ RETURN_STATUS(bc_error_at("bad statement terminator"));
+ }
+ s = zxc_lex_next();
+ if (s) RETURN_STATUS(s);
}
s = zxc_lex_next();
dbg_lex_done("%s:%d done (seen BC_LEX_RBRACE)", __func__, __LINE__);
@@ -4665,9 +4675,11 @@ static BC_STATUS zbc_parse_stmt_or_funcdef(void)
BcStatus s;
dbg_lex_enter("%s:%d entered", __func__, __LINE__);
- if (p->lex == XC_LEX_EOF)
- s = bc_error("end of file");
- else if (p->lex == BC_LEX_KEY_DEFINE) {
+//why?
+// if (p->lex == XC_LEX_EOF)
+// s = bc_error("end of file");
+// else
+ if (p->lex == BC_LEX_KEY_DEFINE) {
dbg_lex("%s:%d p->lex:BC_LEX_KEY_DEFINE", __func__, __LINE__);
s = zbc_parse_funcdef();
} else {
@@ -6781,7 +6793,6 @@ static BC_STATUS zxc_vm_process(const char *text)
s = zxc_parse_text_init(text); // does the first zxc_lex_next()
if (s) RETURN_STATUS(s);
- IF_BC(check_eof:)
while (G.prs.lex != XC_LEX_EOF) {
BcInstPtr *ip;
BcFunc *f;
@@ -6789,14 +6800,6 @@ static BC_STATUS zxc_vm_process(const char *text)
dbg_lex("%s:%d G.prs.lex:%d, parsing...", __func__, __LINE__, G.prs.lex);
if (IS_BC) {
#if ENABLE_BC
- if (G.prs.lex == BC_LEX_SCOLON
- || G.prs.lex == XC_LEX_NLINE
- ) {
- s = zxc_lex_next();
- if (s) goto err;
- goto check_eof;
- }
-
s = zbc_parse_stmt_or_funcdef();
if (s) goto err;
@@ -6855,6 +6858,9 @@ static BC_STATUS zxc_vm_process(const char *text)
#endif
IF_BC(bc_vec_pop_all(&f->strs);)
IF_BC(bc_vec_pop_all(&f->consts);)
+ // We are at SCOLON/NLINE, skip it:
+ s = zxc_lex_next();
+ if (s) goto err;
} else {
if (G.prog.results.len == 0
&& G.prog.vars.len == 0