https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110676
Bug ID: 110676
Summary: builtin optimization prevents ASan from detecting OOB
reads
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: nrk at disroot dot org
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org, marxin at
gcc dot gnu.org
Target Milestone: ---
Minimal reproducible code-snippet:
#include <string.h>
int main(void)
{
char s[1] = "A";
return strlen(s);
}
Compile command: gcc -O0 -g3 -fsanitize=address,undefined
Expected behavior: ASan should catch the OOB access.
Reality: It gets optimized out and returns 0 always.
Note: adding `-fno-builtin` allows ASan to be effective.
