dm: limit the number of targets and parameter size area

The kvmalloc function fails with a warning if the size is larger than
INT_MAX. The warning was triggered by a syscall testing robot.

In order to avoid the warning, this commit limits the number of targets to
1048576 and the size of the parameter area to 1073741824.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
This commit is contained in:
Mikulas Patocka 2024-01-09 15:57:56 +01:00 committed by Mike Snitzer
parent 41bccc98fb
commit bd504bcfec
3 changed files with 11 additions and 3 deletions

View File

@ -22,6 +22,8 @@
#include "dm-ima.h"
#define DM_RESERVED_MAX_IOS 1024
#define DM_MAX_TARGETS 1048576
#define DM_MAX_TARGET_PARAMS 1024
struct dm_io;

View File

@ -1941,7 +1941,8 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern
minimum_data_size - sizeof(param_kernel->version)))
return -EFAULT;
if (param_kernel->data_size < minimum_data_size) {
if (unlikely(param_kernel->data_size < minimum_data_size) ||
unlikely(param_kernel->data_size > DM_MAX_TARGETS * DM_MAX_TARGET_PARAMS)) {
DMERR("Invalid data size in the ioctl structure: %u",
param_kernel->data_size);
return -EINVAL;

View File

@ -129,7 +129,12 @@ static int alloc_targets(struct dm_table *t, unsigned int num)
int dm_table_create(struct dm_table **result, blk_mode_t mode,
unsigned int num_targets, struct mapped_device *md)
{
struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
struct dm_table *t;
if (num_targets > DM_MAX_TARGETS)
return -EOVERFLOW;
t = kzalloc(sizeof(*t), GFP_KERNEL);
if (!t)
return -ENOMEM;
@ -144,7 +149,7 @@ int dm_table_create(struct dm_table **result, blk_mode_t mode,
if (!num_targets) {
kfree(t);
return -ENOMEM;
return -EOVERFLOW;
}
if (alloc_targets(t, num_targets)) {