https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120658
Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |INVALID
CC| |ebotcazou at gcc dot gnu.org
Status|UNCONFIRMED |RESOLVED
--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Compiling with -fsanitize=address -g yields:
TO_BASE( (uint)x1i, 10 ) : 4287654321
=================================================================
==11341==ERROR: AddressSanitizer: stack-use-after-scope on address
0x7fca89d000d6 at pc 0x7fca8be9ef7c bp 0x7ffeeb477d40 sp 0x7ffeeb477500
READ of size 11 at 0x7fca89d000d6 thread T0
#0 0x7fca8be9ef7b (/usr/lib64/libasan.so.8+0x9ef7b) (BuildId:
4ee117fa2a132af1da9f17a0a5fe1f888398d50f)
#1 0x7fca8becac3a in vprintf (/usr/lib64/libasan.so.8+0xcac3a) (BuildId:
4ee117fa2a132af1da9f17a0a5fe1f888398d50f)
#2 0x7fca8becc82e in printf (/usr/lib64/libasan.so.8+0xcc82e) (BuildId:
4ee117fa2a132af1da9f17a0a5fe1f888398d50f)
#3 0x401198 in main /home/eric/bin_dec_conversion.c:159
#4 0x7fca8ba40e6b in __libc_start_call_main (/lib64/libc.so.6+0x40e6b)
(BuildId: 8cd6cc55dddb025d49c90d45e7ace66d04f55c4a)
#5 0x7fca8ba40f34 in __libc_start_main_alias_1 (/lib64/libc.so.6+0x40f34)
(BuildId: 8cd6cc55dddb025d49c90d45e7ace66d04f55c4a)
#6 0x400ac0 in _start ../sysdeps/x86_64/start.S:115
Address 0x7fca89d000d6 is located in stack of thread T0 at offset 214 in frame
#0 0x400ccc in main /home/eric/bin_dec_conversion.c:140
This frame has 11 object(s):
[32, 36) 'x1i' (line 142)
[48, 56) 'start1' (line 141)
[80, 88) 'end1' (line 141)
[112, 145) '<unknown>'
[192, 225) '<unknown>' <== Memory access at offset 214 is inside this
variable
[272, 305) '<unknown>'
[352, 385) '<unknown>'
[432, 465) '<unknown>'
[512, 545) '<unknown>'
[592, 848) 'chbuf256' (line 144)
[912, 1169) 'chbuf257' (line 146)
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-scope
(/usr/lib64/libasan.so.8+0x9ef7b) (BuildId:
4ee117fa2a132af1da9f17a0a5fe1f888398d50f)
Shadow bytes around the buggy address:
0x7fca89cffe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7fca89cffe80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7fca89cfff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7fca89cfff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7fca89d00000: f1 f1 f1 f1 04 f2 00 f2 f2 f2 00 f2 f2 f2 00 00
=>0x7fca89d00080: 00 00 01 f2 f2 f2 f2 f2 f8 f8[f8]f8 f8 f2 f2 f2
0x7fca89d00100: f2 f2 00 00 00 00 01 f2 f2 f2 f2 f2 00 00 00 00
0x7fca89d00180: 01 f2 f2 f2 f2 f2 00 00 00 00 01 f2 f2 f2 f2 f2
0x7fca89d00200: 00 00 00 00 01 f2 f2 f2 f2 f2 00 00 00 00 00 00
0x7fca89d00280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
0x7fca89d00300: 00 00 00 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 f2
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
In other words, there is a buffer overflow in the code caused by the compound
literal nested in the TO_BASE macro.
