https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108904
Bug ID: 108904 Summary: ASAN at -O2/3 missed a global buffer overflow Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: sanitizer Assignee: unassigned at gcc dot gnu.org Reporter: shaohua.li at inf dot ethz.ch 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: --- For the following code, ASAN at -O2/3 missed the global-buffer-overflow. Compiler explorer: https://godbolt.org/z/zjed8vzhj % cat a.c int a, b, c = 3, d; static int *e = &c, *f, *g = &e; short h, i; int(j)(int k) { return k==0 ?0: a; } int *l(int* p) { return &b; } int main() { for (; h >= 0; h--) { b = j(*e); if (*e | *(&d + 1)) ++i; } f = l(g); __builtin_printf("%d\n", i); } % % gcc-tk -O2 -fsanitize=address -w a.c && ./a.out 1 % gcc-tk -O1 -fsanitize=address -w a.c && ./a.out ================================================================= ==1==ERROR: AddressSanitizer: global-buffer-overflow on address 0x000000404424 at pc 0x0000004011fd bp 0x7ffe0ae032c0 sp 0x7ffe0ae032b8 READ of size 4 at 0x000000404424 thread T0 #0 0x4011fc in main /app/a.c:11 #1 0x7fb7968aa082 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24082) (BuildId: 1878e6b475720c7c51969e69ab2d276fae6d1dee) #2 0x4010bd in _start (/app/a.s+0x4010bd) (BuildId: ad1fc5fb90a08d043b6c529370650d444b96c26e) 0x000000404424 is located 60 bytes before global variable 'b' defined in '/app/a.c' (0x404460) of size 4 0x000000404424 is located 0 bytes after global variable 'd' defined in '/app/a.c' (0x404420) of size 4 ... %