github-repos/tinycc
1
0
Fork 0
mirror of https://github.com/mirror/tinycc.git synced 2025-02-04 06:30:10 +08:00
Code Issues Packages Projects Releases Wiki Activity

Fix invalid memory access in preprocess_end

Browse Source 
when an error is thrown macro_stack might point to
unwound local variables, we can't access them.
This commit is contained in:
Michael Matz 2019-03-15 13:17:58 +01:00
parent be7c870718
commit d72b877e45
1 changed files with 7 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
tccpp.c
View File

@ -3625,8 +3625,13 @@ ST_FUNC void preprocess_start(TCCState *s1, int is_asm)
/* cleanup from error/setjmp */
ST_FUNC void preprocess_end(TCCState *s1)
{
while (macro_stack)
end_macro();
/* Normally macro_stack is NULL here, except if an
error was thrown; then it can point to allocated storage
or to some stack variables, but those are unwound via
setjmp already, so can't be accessed. Only two choices:
either we leak memory or we access invalid memory. The
former is the better choice. */
macro_stack = NULL;
macro_ptr = NULL;
}