x86, ptrace: add buffer size checks
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>
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 236528b..e19a91d 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -591,6 +591,7 @@
}
static int ptrace_bts_drain(struct task_struct *child,
+ long size,
struct bts_struct __user *out)
{
int end, i;
@@ -603,6 +604,9 @@
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 @@
ds_clear(ds);
- return i;
+ return end;
}
static int ptrace_bts_realloc(struct task_struct *child,
@@ -690,15 +694,22 @@
}
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 @@
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_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 @@
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 @@
case PTRACE_BTS_DRAIN:
ret = ptrace_bts_drain
- (child, (struct bts_struct __user *) addr);
+ (child, data, (struct bts_struct __user *) addr);
break;
default: