From: Corinna Vinschen <[email protected]>
c32rtomb neglects to check the input character for being outside
the valid UNICODE planes. It happily converts the invalid character
into a valid (but wrong) surrogate pair and carries on.
Add a check so characters beyond 0x10ffff are not converted anymore.
Return -1 with errno set to EILSEQ instead.
Fixes: 4f258c55e87f ("Cygwin: Add ISO C11 functions c16rtomb, c32rtomb,
mbrtoc16, mbrtoc32.")
Signed-off-by: Corinna Vinschen <[email protected]>
---
winsup/cygwin/release/3.6.7 | 5 +++++
winsup/cygwin/strfuncs.cc | 7 +++++++
2 files changed, 12 insertions(+)
create mode 100644 winsup/cygwin/release/3.6.7
diff --git a/winsup/cygwin/release/3.6.7 b/winsup/cygwin/release/3.6.7
new file mode 100644
index 000000000000..defe55ffe75e
--- /dev/null
+++ b/winsup/cygwin/release/3.6.7
@@ -0,0 +1,5 @@
+Fixes:
+------
+
+- Guard c32rtomb against invalid input characters.
+ Addresses a testsuite error in current gawk git master.
diff --git a/winsup/cygwin/strfuncs.cc b/winsup/cygwin/strfuncs.cc
index eb6576051d90..0cf41cefc8a2 100644
--- a/winsup/cygwin/strfuncs.cc
+++ b/winsup/cygwin/strfuncs.cc
@@ -146,6 +146,13 @@ c32rtomb (char *s, char32_t wc, mbstate_t *ps)
if (wc <= 0xffff || !s)
return wcrtomb (s, (wchar_t) wc, ps);
+ /* Check for character outside valid UNICODE planes */
+ if (wc > 0x10ffff)
+ {
+ _REENT_ERRNO(_REENT) = EILSEQ;
+ return (size_t)(-1);
+ }
+
wchar_t wc_arr[2];
const wchar_t *wcp = wc_arr;
--
2.52.0
