Buffer Overflow Failing In Linux?

I have a question about buffer overflaw, in this program :

#include <stdio.h>
#include <string.h>


int main(int argc, char **argv) {

char buf[10];

if(argc < 2) return 1;

strcpy(buf, argv[1]);

printf("%s\n", buf);

return 0;
}

when I try to make this program flow in the memory :

[Barakat/at/System ~]$ gdb buff 
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<>...
Reading symbols from /home/Barakat/buff...(no debugging symbols found)...done.
(gdb) run AAAAAAAAAAAAAAAAAAAAAAAAAAAA
Starting program: /home/Barakat/buff AAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAA

Program received signal SIGSEGV, Se开发者_开发知识库gmentation fault.
0x08048434 in main ()
Missing separate debuginfos, use: debuginfo-install glibc-2.12.1-4.i686
(gdb) info registers 
eax            0x0    0
ecx            0xbcd4e0    12375264
edx            0xbce340    12378944
ebx            0xbccff4    12374004
esp            0xbffff26c    0xbffff26c
ebp            0x41414141    0x41414141
esi            0x0    0
edi            0x0    0
eip            0x8048434    0x8048434 <main+64>
eflags         0x210246    [ PF ZF IF RF ID ]
cs             0x73    115
ss             0x7b    123
ds             0x7b    123
es             0x7b    123
fs             0x0    0
gs             0x33    51
(gdb)

It should to be like this :

**Program received signal SIGSEGV, Segmentation fault. 
0x41414141 in ?? ()**
(gdb) info registers 
eax 0x0 0 
ecx 0x1000 4096 
edx 0xd1c448 13747272 
ebx 0xd1aff4 13742068 
esp 0xbfffdcd0 0xbfffdcd0 
**ebp 0x41414141 0x41414141** 
esi 0x0 0 
edi 0xa38cc0 10718400 
[COLOR="Red"][B]eip 0x41414141 0x41414141 [/B][/COLOR]
eflags 0x210286 [ PF SF IF RF ID ] 
cs 0x73 115 
ss 0x7b 123 
ds 0x7b 123 
es 0x7b 123 
fs 0x0 0 
gs 0x33 51 
(gdb)

So that A (41 in hex) should to be written on the EPI but that didn't happen

Does linux have a way to protect itself against buffer overflows so that the buffer overflow fail ? or there is something I did it wrong ?

You seem to be expecting AAA... in EIP and a subsequent instruction fetch fault.

But the program seems to have actually failed⁽¹⁾ by attempting to load AAA... as data.

In fact, my guess is, it "restored" EBP from the corrupted stack, and then tried to load AAA... + (small offset) in order to restore some other register.

And that gave you your segfault.

^{(1) Getting a SEGV at all would suggest that you or your distro are compiling with -fno-stack-protector.}

Yes, the CPU marks memory segments and pages as writable and executable. If you attempt to do something that isn't permitted by the OS (not marked as executable or writable) it will make the CPU raise an interrupt which will be handled by the OS. In the case of UNIX like operating systems the OS will send a SIGSEGV signal (which is handleable, but cannot be recovered from) to the process in which the access violation occured.

It seems like you're overflowing well past the end of the stack frame.