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x86, ptrace: add buffer size checks

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Pass the buffer size for (most) ptrace commands that pass user-allocated buffers and check that size before accessing the buffer. Unfortunately, PTRACE_BTS_GET already uses all 4 parameters.
Commands that access user buffers return the number of bytes or records read or written.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Markus Metzger 2008-01-30 13:32:03 +01:00 committed by Ingo Molnar
parent e6ae5d9540
commit cba4b65d35
2 changed files with 29 additions and 10 deletions
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25
arch/x86/kernel/ptrace.c
View file

@ -591,6 +591,7 @@ static int ptrace_bts_clear(struct task_struct *child)
}
static int ptrace_bts_drain(struct task_struct *child,
long size,
struct bts_struct __user *out)
{
int end, i;
@ -603,6 +604,9 @@ static int ptrace_bts_drain(struct task_struct *child,
if (end <= 0)
return end;
if (size < (end * sizeof(struct bts_struct)))
return -EIO;
for (i = 0; i < end; i++, out++) {
struct bts_struct ret;
int retval;
@ -617,7 +621,7 @@ static int ptrace_bts_drain(struct task_struct *child,
ds_clear(ds);
return i;
return end;
}
static int ptrace_bts_realloc(struct task_struct *child,
@ -690,15 +694,22 @@ static int ptrace_bts_realloc(struct task_struct *child,
}
static int ptrace_bts_config(struct task_struct *child,
long cfg_size,
const struct ptrace_bts_config __user *ucfg)
{
struct ptrace_bts_config cfg;
int bts_size, ret = 0;
void *ds;
if (cfg_size < sizeof(cfg))
return -EIO;
if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
return -EFAULT;
if ((int)cfg.size < 0)
return -EINVAL;
bts_size = 0;
ds = (void *)child->thread.ds_area_msr;
if (ds) {
@ -734,6 +745,8 @@ static int ptrace_bts_config(struct task_struct *child,
else
clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
ret = sizeof(cfg);
out:
if (child->thread.debugctlmsr)
set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
@ -749,11 +762,15 @@ static int ptrace_bts_config(struct task_struct *child,
}
static int ptrace_bts_status(struct task_struct *child,
long cfg_size,
struct ptrace_bts_config __user *ucfg)
{
void *ds = (void *)child->thread.ds_area_msr;
struct ptrace_bts_config cfg;
if (cfg_size < sizeof(cfg))
return -EIO;
memset(&cfg, 0, sizeof(cfg));
if (ds) {
@ -923,12 +940,12 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
case PTRACE_BTS_CONFIG:
ret = ptrace_bts_config
(child, (struct ptrace_bts_config __user *)addr);
(child, data, (struct ptrace_bts_config __user *)addr);
break;
case PTRACE_BTS_STATUS:
ret = ptrace_bts_status
(child, (struct ptrace_bts_config __user *)addr);
(child, data, (struct ptrace_bts_config __user *)addr);
break;
case PTRACE_BTS_SIZE:
@ -946,7 +963,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
case PTRACE_BTS_DRAIN:
ret = ptrace_bts_drain
(child, (struct bts_struct __user *) addr);
(child, data, (struct bts_struct __user *) addr);
break;
default:

14
include/asm-x86/ptrace-abi.h
View file

@ -99,13 +99,15 @@ struct ptrace_bts_config {
#define PTRACE_BTS_CONFIG 40
/* Configure branch trace recording.
DATA is ignored, ADDR points to a struct ptrace_bts_config.
ADDR points to a struct ptrace_bts_config.
DATA gives the size of that buffer.
A new buffer is allocated, iff the size changes.
Returns the number of bytes read.
*/
#define PTRACE_BTS_STATUS 41
/* Return the current configuration.
DATA is ignored, ADDR points to a struct ptrace_bts_config
that will contain the result.
/* Return the current configuration in a struct ptrace_bts_config
pointed to by ADDR; DATA gives the size of that buffer.
Returns the number of bytes written.
*/
#define PTRACE_BTS_SIZE 42
/* Return the number of available BTS records.
@ -123,8 +125,8 @@ struct ptrace_bts_config {
*/
#define PTRACE_BTS_DRAIN 45
/* Read all available BTS records and clear the buffer.
DATA is ignored. ADDR points to an array of struct bts_struct of
suitable size.
ADDR points to an array of struct bts_struct.
DATA gives the size of that buffer.
BTS records are read from oldest to newest.
Returns number of BTS records drained.
*/