From: Mikulas Patocka mpatocka@redhat.com

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.

Signed-off-by: Mikulas Patocka mpatocka@redhat.com Signed-off-by: Mike Snitzer snitzer@kernel.org Signed-off-by: He Gao hegao@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org [srish: Apply to stable branch linux-4.19.y] Signed-off-by: Srish Srinivasan srish.srinivasan@broadcom.com --- 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(-)

diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h index 8cda3f7dd..2542f0881 100644 --- a/drivers/md/dm-core.h +++ b/drivers/md/dm-core.h @@ -18,6 +18,8 @@ #include "dm.h"

#define DM_RESERVED_MAX_IOS 1024 +#define DM_MAX_TARGETS 1048576 +#define DM_MAX_TARGET_PARAMS 1024

struct dm_kobject_holder { struct kobject kobj; diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 88e89796c..70929ff79 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1734,7 +1734,8 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern if (copy_from_user(param_kernel, user, minimum_data_size)) 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)) return -EINVAL;

secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG; diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 3faaf21be..4822f66b0 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -187,7 +187,12 @@ static int alloc_targets(struct dm_table *t, unsigned int num) int dm_table_create(struct dm_table **result, fmode_t mode, unsigned 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; @@ -202,7 +207,7 @@ int dm_table_create(struct dm_table **result, fmode_t mode,

if (!num_targets) { kfree(t); - return -ENOMEM; + return -EOVERFLOW; }

if (alloc_targets(t, num_targets)) {