This is the mail archive of the
glibc-bugs@sourceware.org
mailing list for the glibc project.
[Bug libc/21746] New: __stack_chk_fail should keep stack usage to minimal
- From: "hjl.tools at gmail dot com" <sourceware-bugzilla at sourceware dot org>
- To: glibc-bugs at sourceware dot org
- Date: Mon, 10 Jul 2017 16:56:48 +0000
- Subject: [Bug libc/21746] New: __stack_chk_fail should keep stack usage to minimal
- Auto-submitted: auto-generated
https://sourceware.org/bugzilla/show_bug.cgi?id=21746
Bug ID: 21746
Summary: __stack_chk_fail should keep stack usage to minimal
Product: glibc
Version: 2.26
Status: NEW
Severity: normal
Priority: P2
Component: libc
Assignee: unassigned at sourceware dot org
Reporter: hjl.tools at gmail dot com
CC: drepper.fsp at gmail dot com
Target Milestone: ---
After stack is compromised, stack unwinding becomes unreliable:
[hjl@gnu-6 tmp]$ cat ssp-1.c
int main (void)
{
int i = 0;
char foo[255];
/* Overflow buffer. */
for (i = 0; i < 400; i++)
foo[i] = 42;
return 1; /* fail */
}
[hjl@gnu-6 tmp]$ gcc ssp-1.c -g -fstack-protector
[hjl@gnu-6 tmp]$ ./a.out
*** stack smashing detected ***: ./a.out terminated
Segmentation fault
[hjl@gnu-6 tmp]$ gdb a.out
GNU gdb (GDB) Fedora 8.0-13.0.fc25
Copyright (C) 2017 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from a.out...done.
(gdb) r
Starting program: /tmp/a.out
Missing separate debuginfos, use: dnf debuginfo-install
glibc-2.24-9.0.fc25.x86_64
*** stack smashing detected ***: /tmp/a.out terminated
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7806c8b in ?? () from /lib64/libgcc_s.so.1
Missing separate debuginfos, use: dnf debuginfo-install
libgcc-6.3.1-3.2.fc25.x86_64
(gdb) bt
#0 0x00007ffff7806c8b in ?? () from /lib64/libgcc_s.so.1
#1 0x00007ffff7808628 in _Unwind_Backtrace () from /lib64/libgcc_s.so.1
#2 0x00007ffff7b26b8f in backtrace () from /lib64/libc.so.6
#3 0x00007ffff7a2efb6 in backtrace_and_maps () from /lib64/libc.so.6
#4 0x00007ffff7a886eb in __libc_message () from /lib64/libc.so.6
#5 0x00007ffff7b2a387 in __fortify_fail () from /lib64/libc.so.6
#6 0x00007ffff7b2a350 in __stack_chk_fail () from /lib64/libc.so.6
#7 0x0000000000400592 in main () at ssp-1.c:11
(gdb)
--
You are receiving this mail because:
You are on the CC list for the bug.