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@xxxxxxxxxx>
---
drivers/md/dm-core.h | 2 ++
drivers/md/dm-ioctl.c | 3 ++-
drivers/md/dm-table.c | 9 +++++++--
3 files changed, 11 insertions(+), 3 deletions(-)
Index: linux-2.6/drivers/md/dm-core.h
===================================================================
--- linux-2.6.orig/drivers/md/dm-core.h 2024-01-09 12:03:27.000000000 +0100
+++ linux-2.6/drivers/md/dm-core.h 2024-01-09 12:03:27.000000000 +0100
@@ -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;
Index: linux-2.6/drivers/md/dm-ioctl.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-ioctl.c 2024-01-09 12:03:27.000000000 +0100
+++ linux-2.6/drivers/md/dm-ioctl.c 2024-01-09 12:03:27.000000000 +0100
@@ -1941,7 +1941,8 @@ static int copy_params(struct dm_ioctl _
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;
Index: linux-2.6/drivers/md/dm-table.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-table.c 2024-01-09 12:03:27.000000000 +0100
+++ linux-2.6/drivers/md/dm-table.c 2024-01-09 12:03:27.000000000 +0100
@@ -129,7 +129,12 @@ static int alloc_targets(struct dm_table
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 **re
if (!num_targets) {
kfree(t);
- return -ENOMEM;
+ return -EOVERFLOW;
}
if (alloc_targets(t, num_targets)) {
