4.19-stable review patch. If anyone has any objections, please let me know.
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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 [srish: Apply to stable branch linux-4.19.y] Signed-off-by: Srish Srinivasan srish.srinivasan@broadcom.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(-)
--- 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; --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1734,7 +1734,8 @@ static int copy_params(struct dm_ioctl _ 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; --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -187,7 +187,12 @@ static int alloc_targets(struct dm_table 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 **re
if (!num_targets) { kfree(t); - return -ENOMEM; + return -EOVERFLOW; }
if (alloc_targets(t, num_targets)) {