(perl #129340) copy the source when inside the dest in sv_insert_flags()

diff --git a/embed.fnc b/embed.fnc
index 0f63ed0..3b64514 100644 (file)
--- a/embed.fnc
+++ b/embed.fnc
@@ -1553,7 +1553,7 @@ Apmdb     |void   |sv_insert      |NN SV *const bigstr|const STRLEN offset \
                                |const STRLEN len|NN const char *const little \
                                |const STRLEN littlelen
 Apd    |void   |sv_insert_flags|NN SV *const bigstr|const STRLEN offset|const STRLEN len \
-                               |NN const char *const little|const STRLEN littlelen|const U32 flags
+                               |NN const char *little|const STRLEN littlelen|const U32 flags
 Apd    |int    |sv_isa         |NULLOK SV* sv|NN const char *const name
 Apd    |int    |sv_isobject    |NULLOK SV* sv
 Apd    |STRLEN |sv_len         |NULLOK SV *const sv

diff --git a/proto.h b/proto.h
index c61980e..59f9b4b 100644 (file)
--- a/proto.h
+++ b/proto.h
@@ -3113,7 +3113,7 @@ PERL_CALLCONV void        Perl_sv_insert(pTHX_ SV *const bigstr, const STRLEN offset, c
 #define PERL_ARGS_ASSERT_SV_INSERT     \
        assert(bigstr); assert(little)
 #endif
-PERL_CALLCONV void     Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *const little, const STRLEN littlelen, const U32 flags);
+PERL_CALLCONV void     Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *little, const STRLEN littlelen, const U32 flags);
 #define PERL_ARGS_ASSERT_SV_INSERT_FLAGS       \
        assert(bigstr); assert(little)
 PERL_CALLCONV int      Perl_sv_isa(pTHX_ SV* sv, const char *const name);

diff --git a/sv.c b/sv.c
index e0c327a..e90ea84 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -6328,7 +6328,7 @@ C<SvPV_force_flags> that applies to C<bigstr>.
 */
 
 void
-Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *const little, const STRLEN littlelen, const U32 flags)
+Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN len, const char *little, const STRLEN littlelen, const U32 flags)
 {
     char *big;
     char *mid;
@@ -6341,6 +6341,16 @@ Perl_sv_insert_flags(pTHX_ SV *const bigstr, const STRLEN offset, const STRLEN l
 
     SvPV_force_flags(bigstr, curlen, flags);
     (void)SvPOK_only_UTF8(bigstr);
+
+    if (little >= SvPVX(bigstr) &&
+        little < SvPVX(bigstr) + (SvLEN(bigstr) ? SvLEN(bigstr) : SvCUR(bigstr))) {
+        /* little is a pointer to within bigstr, since we can reallocate bigstr,
+           or little...little+littlelen might overlap offset...offset+len we make a copy
+        */
+        little = savepvn(little, littlelen);
+        SAVEFREEPV(little);
+    }
+
     if (offset + len > curlen) {
        SvGROW(bigstr, offset+len+1);
        Zero(SvPVX(bigstr)+curlen, offset+len-curlen, char);

diff --git a/t/op/substr.t b/t/op/substr.t
index 83e7bae..a8abed8 100644 (file)
--- a/t/op/substr.t
+++ b/t/op/substr.t
@@ -22,7 +22,7 @@ $SIG{__WARN__} = sub {
      }
 };
 
-plan(390);
+plan(391);
 
 run_tests() unless caller;
 
@@ -877,3 +877,6 @@ is($destroyed, 1, 'Timely scalar destruction with lvalue substr');
 
     is($result_3363, "best", "ref-to-substr retains lvalue-ness under recursion [perl #3363]");
 }
+
+# failed with ASAN
+fresh_perl_is('$0 = "/usr/bin/perl"; substr($0, 0, 0, $0)', '', {}, "(perl #129340) substr() with source in target");