[sfnt] Fix memory leak in png loading.
Reported as
https://bugs.chromium.org/p/chromium/issues/detail?id=1182552
Memory is allocated and the pointer assigned to `rows` inside a
'setjmp' scope. This memory must be freed outside the 'setjmp'
scope after a 'longjmp'. Since `rows` is a local and modified
inside the 'setjmp' scope it must be marked volatile or it will have
an indeterminate value after the 'longjmp'.
* src/sfnt/pngshim.c (Load_SBit_Png): Fix memory leak of `rows`.
diff --git a/ChangeLog b/ChangeLog
index 1883fda..3535d06 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2021-03-16 Ben Wagner <bungeman@google.com>
+
+ [sfnt] Fix memory leak in png loading.
+
+ Reported as
+
+ https://bugs.chromium.org/p/chromium/issues/detail?id=1182552
+
+ Memory is allocated and the pointer assigned to `rows` inside a
+ 'setjmp' scope. This memory must be freed outside the 'setjmp'
+ scope after a 'longjmp'. Since `rows` is a local and modified
+ inside the 'setjmp' scope it must be marked volatile or it will have
+ an indeterminate value after the 'longjmp'.
+
+ * src/sfnt/pngshim.c (Load_SBit_Png): Fix memory leak of `rows`.
+
2021-03-16 Christopher Degawa <ccom@randomderp.com>
* CMakeLists.txt: Don't limit generation of 'pkg-config' file to UNIX.
diff --git a/src/sfnt/pngshim.c b/src/sfnt/pngshim.c
index c7a2938..3ef7b43 100644
--- a/src/sfnt/pngshim.c
+++ b/src/sfnt/pngshim.c
@@ -270,7 +270,10 @@
int bitdepth, color_type, interlace;
FT_Int i;
- png_byte* *rows = NULL; /* pacify compiler */
+
+ /* `rows` gets modified within a 'setjmp' scope; */
+ /* we thus need the `volatile` keyword. */
+ png_byte* *volatile rows = NULL;
if ( x_offset < 0 ||
