https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108407
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |INVALID
Status|UNCONFIRMED |RESOLVED
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
With -fsanitize=undefined,address we get:
=================================================================
==1==ERROR: AddressSanitizer: stack-use-after-return on address 0x7ff991800030
at pc 0x0000004016c4 bp 0x7ffd675ea150 sp 0x7ffd675ea148
READ of size 4 at 0x7ff991800030 thread T0
#0 0x4016c3 in main /app/example.cpp:19
#1 0x7ff993d50082 in __libc_start_main
(/lib/x86_64-linux-gnu/libc.so.6+0x24082) (BuildId:
1878e6b475720c7c51969e69ab2d276fae6d1dee)
#2 0x40115d in _start (/app/output.s+0x40115d) (BuildId:
c6fef22ac59389c6ed0248b91200737f3dfa67d0)
Address 0x7ff991800030 is located in stack of thread T0 at offset 48 in frame
#0 0x401225 in create() /app/example.cpp:7
This frame has 2 object(s):
[48, 52) 'a' (line 8) <== Memory access at offset 48 is inside this
variable
[64, 72) 'b' (line 9)
HINT: this may be a false positive if your program uses some custom stack
unwind mechanism, swapcontext or vfork
(longjmp and C++ exceptions *are* supported)
SUMMARY: AddressSanitizer: stack-use-after-return /app/example.cpp:19 in main
Shadow bytes around the buggy address:
0x7ff9917ffd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7ff9917ffe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7ff9917ffe80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7ff9917fff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7ff9917fff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
=>0x7ff991800000: f5 f5 f5 f5 f5 f5[f5]f5 f5 f5 f5 f5 00 00 00 00
0x7ff991800080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7ff991800100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7ff991800180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7ff991800200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7ff991800280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
Left alloca redzone: ca
Right alloca redzone: cb
==1==ABORTING
