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 <[email protected]> --- 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)) {
