dm: limit the number of targets and parameter size area
commit bd504bcfec41a503b32054da5472904b404341a4 upstream.
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.
BUG=b/322958349
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2024-23851 in the Linux kernel.
cos-patch: security-moderate
Change-Id: Ie22a90c2b54e8fceaa8929c4641aca3aa6bbbae6
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/65650
Reviewed-by: Michael Kochera <kochera@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Main-Branch-Verified: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index 71dcd8fd..6314210 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -21,6 +21,8 @@
#include "dm-ima.h"
#define DM_RESERVED_MAX_IOS 1024
+#define DM_MAX_TARGETS 1048576
+#define DM_MAX_TARGET_PARAMS 1024
struct dm_io;
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 206e6ce..4376754 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1877,7 +1877,8 @@
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;
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index dac6a5f..e0367a67 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -128,7 +128,12 @@
int dm_table_create(struct dm_table **result, fmode_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;
@@ -143,7 +148,7 @@
if (!num_targets) {
kfree(t);
- return -ENOMEM;
+ return -EOVERFLOW;
}
if (alloc_targets(t, num_targets)) {
