Remote Debugging Linux Binaries - Stack Address Changes?
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up vote
1
down vote
favorite
Do stack addresses change every time we remotely debug a Linux binary using linux_server
and IDA Pro?
I am using IDA Pro and remote debug a linux binary which is running on a Linux machine and I am using linux_server
as the dbgsrv
.
I noticed that when I enter a subroutine, the stack address is different every time. Is it expected? Is it because I am debugging remotely?
ida linux stack
add a comment |Â
up vote
1
down vote
favorite
Do stack addresses change every time we remotely debug a Linux binary using linux_server
and IDA Pro?
I am using IDA Pro and remote debug a linux binary which is running on a Linux machine and I am using linux_server
as the dbgsrv
.
I noticed that when I enter a subroutine, the stack address is different every time. Is it expected? Is it because I am debugging remotely?
ida linux stack
add a comment |Â
up vote
1
down vote
favorite
up vote
1
down vote
favorite
Do stack addresses change every time we remotely debug a Linux binary using linux_server
and IDA Pro?
I am using IDA Pro and remote debug a linux binary which is running on a Linux machine and I am using linux_server
as the dbgsrv
.
I noticed that when I enter a subroutine, the stack address is different every time. Is it expected? Is it because I am debugging remotely?
ida linux stack
Do stack addresses change every time we remotely debug a Linux binary using linux_server
and IDA Pro?
I am using IDA Pro and remote debug a linux binary which is running on a Linux machine and I am using linux_server
as the dbgsrv
.
I noticed that when I enter a subroutine, the stack address is different every time. Is it expected? Is it because I am debugging remotely?
ida linux stack
ida linux stack
edited 6 mins ago
NirIzr
8,89712268
8,89712268
asked 2 hours ago
Neon Flash
242212
242212
add a comment |Â
add a comment |Â
2 Answers
2
active
oldest
votes
up vote
2
down vote
accepted
On modern Linux machines ASLR is enabled by default. As a result, when the process image for the binary is created in virtual memory, the base address of the stack is located at a random offset:
/*
* These are the functions used to load ELF style executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
#ifndef STACK_RND_MASK
#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
#endif
static unsigned long randomize_stack_top(unsigned long stack_top)
unsigned long random_variable = 0;
if (current->flags & PF_RANDOMIZE)
random_variable = get_random_long();
random_variable &= STACK_RND_MASK;
random_variable <<= PAGE_SHIFT;
#ifdef CONFIG_STACK_GROWSUP
return PAGE_ALIGN(stack_top) + random_variable;
#else
return PAGE_ALIGN(stack_top) - random_variable;
#endif
We can test this with a simple program that prints the memory address of a local variable in function main()
:
#include <stdio.h>
int main(void)
int i = 3;
printf("%pn", &i);
return 0;
compile and execute:
$ gcc -m32 -o print_stack_address print_stack_address.c
$ ./print_stack_address
0xff9dc78c
$ ./print_stack_address
0xff832d3c
$ ./print_stack_address
0xff844c1c
$ ./print_stack_address
0xff999e0c
$ ./print_stack_address
0xffd1117c
Thanks, I resolved this issue by manually disabling ASLR on the machine.
â Neon Flash
1 hour ago
@NeonFlash you are welcome
â SYS_Vâ¦
37 mins ago
add a comment |Â
up vote
1
down vote
Most modern operating systems never guaranteed the stack's location will be the same for different process creations to begin with, and this was mostly a byproduct of deterministic execution of those allocations during the operating system's process creation flow.
Moreover, that fact was then used quite frequently to use constant values for stack addresses during exploitation, which is what ASLR prevents. for a while now stacks are being ASLRed to mitigate exploitation, and are actually guaranteed to be randomized.
add a comment |Â
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
2
down vote
accepted
On modern Linux machines ASLR is enabled by default. As a result, when the process image for the binary is created in virtual memory, the base address of the stack is located at a random offset:
/*
* These are the functions used to load ELF style executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
#ifndef STACK_RND_MASK
#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
#endif
static unsigned long randomize_stack_top(unsigned long stack_top)
unsigned long random_variable = 0;
if (current->flags & PF_RANDOMIZE)
random_variable = get_random_long();
random_variable &= STACK_RND_MASK;
random_variable <<= PAGE_SHIFT;
#ifdef CONFIG_STACK_GROWSUP
return PAGE_ALIGN(stack_top) + random_variable;
#else
return PAGE_ALIGN(stack_top) - random_variable;
#endif
We can test this with a simple program that prints the memory address of a local variable in function main()
:
#include <stdio.h>
int main(void)
int i = 3;
printf("%pn", &i);
return 0;
compile and execute:
$ gcc -m32 -o print_stack_address print_stack_address.c
$ ./print_stack_address
0xff9dc78c
$ ./print_stack_address
0xff832d3c
$ ./print_stack_address
0xff844c1c
$ ./print_stack_address
0xff999e0c
$ ./print_stack_address
0xffd1117c
Thanks, I resolved this issue by manually disabling ASLR on the machine.
â Neon Flash
1 hour ago
@NeonFlash you are welcome
â SYS_Vâ¦
37 mins ago
add a comment |Â
up vote
2
down vote
accepted
On modern Linux machines ASLR is enabled by default. As a result, when the process image for the binary is created in virtual memory, the base address of the stack is located at a random offset:
/*
* These are the functions used to load ELF style executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
#ifndef STACK_RND_MASK
#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
#endif
static unsigned long randomize_stack_top(unsigned long stack_top)
unsigned long random_variable = 0;
if (current->flags & PF_RANDOMIZE)
random_variable = get_random_long();
random_variable &= STACK_RND_MASK;
random_variable <<= PAGE_SHIFT;
#ifdef CONFIG_STACK_GROWSUP
return PAGE_ALIGN(stack_top) + random_variable;
#else
return PAGE_ALIGN(stack_top) - random_variable;
#endif
We can test this with a simple program that prints the memory address of a local variable in function main()
:
#include <stdio.h>
int main(void)
int i = 3;
printf("%pn", &i);
return 0;
compile and execute:
$ gcc -m32 -o print_stack_address print_stack_address.c
$ ./print_stack_address
0xff9dc78c
$ ./print_stack_address
0xff832d3c
$ ./print_stack_address
0xff844c1c
$ ./print_stack_address
0xff999e0c
$ ./print_stack_address
0xffd1117c
Thanks, I resolved this issue by manually disabling ASLR on the machine.
â Neon Flash
1 hour ago
@NeonFlash you are welcome
â SYS_Vâ¦
37 mins ago
add a comment |Â
up vote
2
down vote
accepted
up vote
2
down vote
accepted
On modern Linux machines ASLR is enabled by default. As a result, when the process image for the binary is created in virtual memory, the base address of the stack is located at a random offset:
/*
* These are the functions used to load ELF style executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
#ifndef STACK_RND_MASK
#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
#endif
static unsigned long randomize_stack_top(unsigned long stack_top)
unsigned long random_variable = 0;
if (current->flags & PF_RANDOMIZE)
random_variable = get_random_long();
random_variable &= STACK_RND_MASK;
random_variable <<= PAGE_SHIFT;
#ifdef CONFIG_STACK_GROWSUP
return PAGE_ALIGN(stack_top) + random_variable;
#else
return PAGE_ALIGN(stack_top) - random_variable;
#endif
We can test this with a simple program that prints the memory address of a local variable in function main()
:
#include <stdio.h>
int main(void)
int i = 3;
printf("%pn", &i);
return 0;
compile and execute:
$ gcc -m32 -o print_stack_address print_stack_address.c
$ ./print_stack_address
0xff9dc78c
$ ./print_stack_address
0xff832d3c
$ ./print_stack_address
0xff844c1c
$ ./print_stack_address
0xff999e0c
$ ./print_stack_address
0xffd1117c
On modern Linux machines ASLR is enabled by default. As a result, when the process image for the binary is created in virtual memory, the base address of the stack is located at a random offset:
/*
* These are the functions used to load ELF style executables and shared
* libraries. There is no binary dependent code anywhere else.
*/
#ifndef STACK_RND_MASK
#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
#endif
static unsigned long randomize_stack_top(unsigned long stack_top)
unsigned long random_variable = 0;
if (current->flags & PF_RANDOMIZE)
random_variable = get_random_long();
random_variable &= STACK_RND_MASK;
random_variable <<= PAGE_SHIFT;
#ifdef CONFIG_STACK_GROWSUP
return PAGE_ALIGN(stack_top) + random_variable;
#else
return PAGE_ALIGN(stack_top) - random_variable;
#endif
We can test this with a simple program that prints the memory address of a local variable in function main()
:
#include <stdio.h>
int main(void)
int i = 3;
printf("%pn", &i);
return 0;
compile and execute:
$ gcc -m32 -o print_stack_address print_stack_address.c
$ ./print_stack_address
0xff9dc78c
$ ./print_stack_address
0xff832d3c
$ ./print_stack_address
0xff844c1c
$ ./print_stack_address
0xff999e0c
$ ./print_stack_address
0xffd1117c
answered 1 hour ago
SYS_Vâ¦
3,9161940
3,9161940
Thanks, I resolved this issue by manually disabling ASLR on the machine.
â Neon Flash
1 hour ago
@NeonFlash you are welcome
â SYS_Vâ¦
37 mins ago
add a comment |Â
Thanks, I resolved this issue by manually disabling ASLR on the machine.
â Neon Flash
1 hour ago
@NeonFlash you are welcome
â SYS_Vâ¦
37 mins ago
Thanks, I resolved this issue by manually disabling ASLR on the machine.
â Neon Flash
1 hour ago
Thanks, I resolved this issue by manually disabling ASLR on the machine.
â Neon Flash
1 hour ago
@NeonFlash you are welcome
â SYS_Vâ¦
37 mins ago
@NeonFlash you are welcome
â SYS_Vâ¦
37 mins ago
add a comment |Â
up vote
1
down vote
Most modern operating systems never guaranteed the stack's location will be the same for different process creations to begin with, and this was mostly a byproduct of deterministic execution of those allocations during the operating system's process creation flow.
Moreover, that fact was then used quite frequently to use constant values for stack addresses during exploitation, which is what ASLR prevents. for a while now stacks are being ASLRed to mitigate exploitation, and are actually guaranteed to be randomized.
add a comment |Â
up vote
1
down vote
Most modern operating systems never guaranteed the stack's location will be the same for different process creations to begin with, and this was mostly a byproduct of deterministic execution of those allocations during the operating system's process creation flow.
Moreover, that fact was then used quite frequently to use constant values for stack addresses during exploitation, which is what ASLR prevents. for a while now stacks are being ASLRed to mitigate exploitation, and are actually guaranteed to be randomized.
add a comment |Â
up vote
1
down vote
up vote
1
down vote
Most modern operating systems never guaranteed the stack's location will be the same for different process creations to begin with, and this was mostly a byproduct of deterministic execution of those allocations during the operating system's process creation flow.
Moreover, that fact was then used quite frequently to use constant values for stack addresses during exploitation, which is what ASLR prevents. for a while now stacks are being ASLRed to mitigate exploitation, and are actually guaranteed to be randomized.
Most modern operating systems never guaranteed the stack's location will be the same for different process creations to begin with, and this was mostly a byproduct of deterministic execution of those allocations during the operating system's process creation flow.
Moreover, that fact was then used quite frequently to use constant values for stack addresses during exploitation, which is what ASLR prevents. for a while now stacks are being ASLRed to mitigate exploitation, and are actually guaranteed to be randomized.
answered 28 mins ago
NirIzr
8,89712268
8,89712268
add a comment |Â
add a comment |Â
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