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prog:gcc

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prog:gcc [2024/11/12 12:32] – Modification des options de compilation des sanitizers rootprog:gcc [2024/11/12 12:48] (Version actuelle) – Déplacement des sanitizer vers une page dédiée root
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- 
-=====Commun avec clang===== 
-====Sanitizer==== 
-Il existe ''-fsanitize=address,thread,undefined'' mais ''address'' et ''thread'' ne sont pas compatible simultanément. 
- 
- 
-===address=== 
-Il détecte des erreurs de type global-buffer-overflow, heap-use-after-free. 
-[[https://www.youtube.com/watch?v=qTkYDA0En6U|CppCon 2015: Kostya Serebryany “Beyond Sanitizers, Fuzzing and Hardening your C++ apps for Security and Reliability”]] 
- 
-  * global-buffer-overflow 
-<file c main.c> 
-int global_array[100] = {-1}; 
- 
-int main(int argc, char **argv) { 
-  return global_array[argc+100]; 
-} 
-</file> 
- 
-  gcc main.c -g -fsanitize=address -fno-omit-frame-pointer -o main && ./main 
- 
-  ================================================================= 
-  ==2500==ERROR: AddressSanitizer: global-buffer-overflow on address 0x000000740cf4 at pc 0x00000050d9bf bp 0x7ffeabb89b70 sp 0x7ffeabb89b68 
-  READ of size 4 at 0x000000740cf4 thread T0 
-      #0 0x50d9be in main /tmp/main.c:4:10 
-      #1 0x7f1208faa461 in __libc_start_main .../sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 
-      #2 0x419709 in _start (/tmp/main+0x419709) 
-   
-  0x000000740cf4 is located 4 bytes to the right of global variable 'global_array' defined in 'main.c:1:5' (0x740b60) of size 400 
-  SUMMARY: AddressSanitizer: global-buffer-overflow /tmp/main.c:4:10 in main 
-  Shadow bytes around the buggy address: 
-    0x0000800e0140: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0000800e0150: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0000800e0160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0000800e0170: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0000800e0180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-  =>0x0000800e0190: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[f9]f9 
-    0x0000800e01a0: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 
-    0x0000800e01b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0000800e01c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0000800e01d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0000800e01e0: 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 
-  ==2500==ABORTING 
- 
-[[prog:valgrind|valgrind]] ne détecte pas l'erreur. 
- 
-  * heap-use-after-free 
-<file c main2.cc> 
-int main(int argc, char **argv) { 
-  int *array = new int[100]; 
-  delete [] array; 
-  return array[argc]; 
-} 
-</file> 
- 
-  g++ main2.c -g -fsanitize=address -fno-omit-frame-pointer -o main2 && ./main2 
- 
-  ================================================================= 
-  ==2765==ERROR: AddressSanitizer: heap-use-after-free on address 0x614000000044 at pc 0x000000512445 bp 0x7ffd51684f60 sp 0x7ffd51684f58 
-  READ of size 4 at 0x614000000044 thread T0 
-      #0 0x512444 in main /tmp/main2.c:4:10 
-      #1 0x7fd8d0086461 in __libc_start_main .../sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 
-      #2 0x419d29 in _start (/tmp/main2+0x419d29) 
-   
-  0x614000000044 is located 4 bytes inside of 400-byte region [0x614000000040,0x6140000001d0) 
-  freed by thread T0 here: 
-      #0 0x50ef30 in operator delete[](void*) .../sys-libs/compiler-rt-sanitizers-5.0.0/work/compiler-rt-5.0.0.src/lib/asan/asan_new_delete.cc:141 
-      #1 0x5123f6 in main /tmp/main2.c:3:3 
-      #2 0x7fd8d0086461 in __libc_start_main .../sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 
-      #3 0x419d29 in _start (/tmp/main2+0x419d29) 
-     
-  previously allocated by thread T0 here: 
-      #0 0x50e1c8 in operator new[](unsigned long) .../sys-libs/compiler-rt-  sanitizers-5.0.0/work/compiler-rt-5.0.0.src/lib/asan/asan_new_delete.cc:95 
-      #1 0x5123d4 in main /tmp/main2.c:2:16 
-      #2 0x7fd8d0086461 in __libc_start_main .../sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 
-      #3 0x419d29 in _start (/tmp/main2+0x419d29) 
-   
-  SUMMARY: AddressSanitizer: heap-use-after-free /tmp/main2.c:4:10 in main 
-  Shadow bytes around the buggy address: 
-    0x0c287fff7fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0c287fff7fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0c287fff7fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0c287fff7fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0c287fff7ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-  =>0x0c287fff8000: fa fa fa fa fa fa fa fa[fd]fd fd fd fd fd fd fd 
-    0x0c287fff8010: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 
-    0x0c287fff8020: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 
-    0x0c287fff8030: fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa fa 
-    0x0c287fff8040: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 
-    0x0c287fff8050: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa 
- 
-[[prog:valgrind|valgrind]] détecte l'erreur. 
- 
-  ==2787== Command: ./main2 
-  ==2787==  
-  ==2787== Invalid read of size 4 
-  ==2787==    at 0x4005AF: main (main2.c:4) 
-  ==2787==  Address 0x5b25c84 is 4 bytes inside a block of size 400 free'd 
-  ==2787==    at 0x4C2CAA5: operator delete[](void*) (vg_replace_malloc.c:621) 
-  ==2787==    by 0x4005A6: main (main2.c:3) 
-  ==2787==  Block was alloc'd at 
-  ==2787==    at 0x4C2BAC8: operator new[](unsigned long) (vg_replace_malloc.c:423) 
-  ==2787==    by 0x400584: main (main2.c:2) 
- 
-  * stack-use-after-return 
-<file c main3.c> 
-int *g; 
- 
-void LeakLocal() { 
-  int local; 
-  g = &local; 
-} 
- 
-int main(){ 
-  LeakLocal(); 
-  return *g; 
-} 
-</file> 
- 
-  gcc main3.c -g -o main3 -fsanitize=address -fno-omit-frame-pointer 
-  ASAN_OPTIONS=detect_stack_use_after_return=1 ./main3 
- 
-L'utilisation de ''ASAN_OPTIONS=detect_stack_use_after_return=1'' est nécessaire car cette option peut créer des faux positifs. 
- 
-  ================================================================= 
-  ==2907==ERROR: AddressSanitizer: stack-use-after-return on address 0x7f57b2a00020 at pc 0x00000050db25 bp 0x7ffe8dfc7330 sp 0x7ffe8dfc7328 
-  READ of size 4 at 0x7f57b2a00020 thread T0 
-      #0 0x50db24 in main /tmp/main3.c:10:10 
-      #1 0x7f57b604d461 in __libc_start_main .../sys-libs/glibc-2.25-r9/work/glibc-2.25/csu/../csu/libc-start.c:295 
-      #2 0x419709 in _start (/tmp/main3+0x419709) 
-   
-  Address 0x7f57b2a00020 is located in stack of thread T0 at offset 32 in frame 
-      #0 0x50d95f in LeakLocal /tmp/main3.c:3 
-   
-    This frame has 1 object(s): 
-      [32, 36) 'local' (line 4) <== Memory access at offset 32 is inside this variable 
-  HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext 
-        (longjmp and C++ exceptions *are* supported) 
-  SUMMARY: AddressSanitizer: stack-use-after-return /tmp/main3.c:10:10 in main 
-  Shadow bytes around the buggy address: 
-    0x0feb76537fb0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0feb76537fc0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0feb76537fd0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0feb76537fe0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0feb76537ff0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-  =>0x0feb76538000: f5 f5 f5 f5[f5]f5 f5 f5 00 00 00 00 00 00 00 00 
-    0x0feb76538010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0feb76538020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0feb76538030: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0feb76538040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
-    0x0feb76538050: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
- 
-[[prog:valgrind|valgrind]] détecte l'erreur. 
- 
-  valgrind --track-origins=yes ./main3 
- 
-  ==2961== Syscall param exit_group(status) contains uninitialised byte(s) 
-  ==2961==    at 0x4F002B8: _Exit (_exit.c:31) 
-  ==2961==    by 0x4E70423: __run_exit_handlers (exit.c:98) 
-  ==2961==    by 0x4E704DC: exit (exit.c:105) 
-  ==2961==    by 0x4E58468: (below main) (libc-start.c:329) 
-  ==2961==  Uninitialised value was created by a stack allocation 
-  ==2961==    at 0x4004A4: main (main3.c:10) 
- 
-===thread=== 
-<file cpp main4.cc> 
-#include <thread> 
- 
-int main() { 
-  int x; 
-  std::thread t([&]{x=42;}); 
-  x = 43; 
-  t.join(); 
- 
-  return 0; 
-} 
-</file> 
- 
-  g++ -std=c++11 main4.c -g -o main4 -fsanitize=thread -fno-omit-frame-pointer 
- 
-<WRAP center round important 60%> 
-Le plantage reste aléatoire et il est nécessaire de lancer l'application plusieurs fois. 
-</WRAP> 
- 
-  ================== 
-  WARNING: ThreadSanitizer: data race (pid=3226) 
-    Write of size 4 at 0x7ffd04d5b144 by thread T1: 
-      #0 operator() /tmp/main4.c:5 (main4+0x000000400d0b) 
-      #1 __invoke_impl<void, main()::<lambda()> > /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/bits/invoke.h:60 (main4+0x000000401171) 
-      #2 __invoke<main()::<lambda()> > /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/bits/invoke.h:95 (main4+0x000000400e30) 
-      #3 _M_invoke<0> /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/thread:234 (main4+0x0000004014b5) 
-      #4 operator() /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/thread:243 (main4+0x000000401448) 
-      #5 _M_run /usr/lib/gcc/x86_64-pc-linux-gnu/7.2.0/include/g++-v7/thread:186 (main4+0x0000004013ee) 
-      #6 <null> <null> (libstdc++.so.6+0x0000000e251e) 
-   
-    Previous write of size 4 at 0x7ffd04d5b144 by main thread: 
-      #0 main /tmp/main4.c:6 (main4+0x000000400d75) 
-   
-    Location is stack of main thread. 
-   
-    Thread T1 (tid=3228, running) created by main thread at: 
-      #0 pthread_create <null> (libtsan.so.0+0x00000002917a) 
-      #1 std::thread::_M_start_thread(std::unique_ptr<std::thread::_State, std::default_delete<std::thread::_State> >, void (*)()) <null> (libstdc++.so.6+0x0000000e288c) 
-      #2 main /tmp/main4.c:5 (main4+0x000000400d69) 
-   
-  SUMMARY: ThreadSanitizer: data race /tmp/main4.c:5 in operator() 
-  ================== 
-  ThreadSanitizer: reported 1 warnings 
- 
-[[prog:valgrind|valgrind]] ne détecte pas l'erreur. 
- 
-===undefined=== 
-<file c main5.c> 
-int main(int argc, char **argv) { 
-  int t = argc << 16; 
-  return t*t; 
-} 
-</file> 
- 
-  gcc -fsanitize=undefined -fno-sanitize-recover=all -fno-omit-frame-pointer main5.c -g -o main5 
- 
-  main6.c:3:11: runtime error: signed integer overflow: 65536 * 65536 cannot be represented in type 'int' 
- 
-[[prog:valgrind|valgrind]] ne détecte pas l'erreur. 
  
prog/gcc.1731411169.txt.gz · Dernière modification : 2024/11/12 12:32 de root