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yaml
---
r: 360324
b: refs/heads/master
c: 02cde50
h: refs/heads/master
v: v3
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Mikulas Patocka authored and Alasdair G Kergon committed Mar 1, 2013
1 parent eaceeba commit 6df8cf0
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Showing 3 changed files with 38 additions and 22 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: e2914cc26bbca67fd30fff02c6777e8477fc8a6a
refs/heads/master: 02cde50b7ea74557d32ff778c73809322445ccd2
52 changes: 34 additions & 18 deletions trunk/drivers/md/dm-ioctl.c
Original file line number Diff line number Diff line change
Expand Up @@ -1560,74 +1560,89 @@ static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
return r;
}

#define DM_PARAMS_VMALLOC 0x0001 /* Params alloced with vmalloc not kmalloc */
#define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */
#define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */
#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */

static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
{
if (param_flags & DM_WIPE_BUFFER)
memset(param, 0, param_size);

if (param_flags & DM_PARAMS_KMALLOC)
kfree(param);
if (param_flags & DM_PARAMS_VMALLOC)
vfree(param);
else
kfree(param);
}

static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param, int *param_flags)
static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
int ioctl_flags,
struct dm_ioctl **param, int *param_flags)
{
struct dm_ioctl tmp, *dmi;
struct dm_ioctl *dmi;
int secure_data;
const size_t minimum_data_size = sizeof(*param_kernel) - sizeof(param_kernel->data);

if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
if (copy_from_user(param_kernel, user, minimum_data_size))
return -EFAULT;

if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
if (param_kernel->data_size < minimum_data_size)
return -EINVAL;

secure_data = tmp.flags & DM_SECURE_DATA_FLAG;
secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;

*param_flags = secure_data ? DM_WIPE_BUFFER : 0;

if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
dmi = param_kernel;
dmi->data_size = minimum_data_size;
goto data_copied;
}

/*
* Try to avoid low memory issues when a device is suspended.
* Use kmalloc() rather than vmalloc() when we can.
*/
dmi = NULL;
if (tmp.data_size <= KMALLOC_MAX_SIZE)
dmi = kmalloc(tmp.data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
if (dmi)
*param_flags |= DM_PARAMS_KMALLOC;
}

if (!dmi) {
dmi = __vmalloc(tmp.data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH, PAGE_KERNEL);
*param_flags |= DM_PARAMS_VMALLOC;
dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH, PAGE_KERNEL);
if (dmi)
*param_flags |= DM_PARAMS_VMALLOC;
}

if (!dmi) {
if (secure_data && clear_user(user, tmp.data_size))
if (secure_data && clear_user(user, param_kernel->data_size))
return -EFAULT;
return -ENOMEM;
}

if (copy_from_user(dmi, user, tmp.data_size))
if (copy_from_user(dmi, user, param_kernel->data_size))
goto bad;

data_copied:
/*
* Abort if something changed the ioctl data while it was being copied.
*/
if (dmi->data_size != tmp.data_size) {
if (dmi->data_size != param_kernel->data_size) {
DMERR("rejecting ioctl: data size modified while processing parameters");
goto bad;
}

/* Wipe the user buffer so we do not return it to userspace */
if (secure_data && clear_user(user, tmp.data_size))
if (secure_data && clear_user(user, param_kernel->data_size))
goto bad;

*param = dmi;
return 0;

bad:
free_params(dmi, tmp.data_size, *param_flags);
free_params(dmi, param_kernel->data_size, *param_flags);

return -EFAULT;
}
Expand Down Expand Up @@ -1671,6 +1686,7 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
struct dm_ioctl *uninitialized_var(param);
ioctl_fn fn = NULL;
size_t input_param_size;
struct dm_ioctl param_kernel;

/* only root can play with this */
if (!capable(CAP_SYS_ADMIN))
Expand Down Expand Up @@ -1704,7 +1720,7 @@ static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
/*
* Copy the parameters into kernel space.
*/
r = copy_params(user, &param, &param_flags);
r = copy_params(user, &param_kernel, ioctl_flags, &param, &param_flags);

if (r)
return r;
Expand Down
6 changes: 3 additions & 3 deletions trunk/include/uapi/linux/dm-ioctl.h
Original file line number Diff line number Diff line change
Expand Up @@ -267,9 +267,9 @@ enum {
#define DM_DEV_SET_GEOMETRY _IOWR(DM_IOCTL, DM_DEV_SET_GEOMETRY_CMD, struct dm_ioctl)

#define DM_VERSION_MAJOR 4
#define DM_VERSION_MINOR 23
#define DM_VERSION_PATCHLEVEL 1
#define DM_VERSION_EXTRA "-ioctl (2012-12-18)"
#define DM_VERSION_MINOR 24
#define DM_VERSION_PATCHLEVEL 0
#define DM_VERSION_EXTRA "-ioctl (2013-01-15)"

/* Status bits */
#define DM_READONLY_FLAG (1 << 0) /* In/Out */
Expand Down

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