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scsi: tcmu: do not set max_blocks if data_bitmap has been setup 

This patch prevents a bug where data_bitmap is allocated in
tcmu_configure_device, userspace changes the max_blocks setting, the device
is mapped to a LUN, then we try to access the data_bitmap based on the new
max_blocks limit which may now be out of range.

To prevent this, we just check if data_bitmap has been setup. If it has
then we fail the max_blocks update operation.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Mike Christie 2018-07-23 14:07:49 -05:00 committed by Martin K. Petersen
parent dc335a9955
commit c97840c84f
1 changed files with 40 additions and 33 deletions
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73
drivers/target/target_core_user.c
View File

@ -1811,9 +1811,11 @@ static int tcmu_configure_device(struct se_device *dev)
info = &udev->uio_info;
mutex_lock(&udev->cmdr_lock);
udev->data_bitmap = kcalloc(BITS_TO_LONGS(udev->max_blocks),
sizeof(unsigned long),
GFP_KERNEL);
mutex_unlock(&udev->cmdr_lock);
if (!udev->data_bitmap) {
ret = -ENOMEM;
goto err_bitmap_alloc;
@ -2018,7 +2020,7 @@ static match_table_t tokens = {
{Opt_hw_block_size, "hw_block_size=%u"},
{Opt_hw_max_sectors, "hw_max_sectors=%u"},
{Opt_nl_reply_supported, "nl_reply_supported=%d"},
{Opt_max_data_area_mb, "max_data_area_mb=%u"},
{Opt_max_data_area_mb, "max_data_area_mb=%d"},
{Opt_err, NULL}
};
@ -2046,13 +2048,48 @@ static int tcmu_set_dev_attrib(substring_t *arg, u32 *dev_attrib)
return 0;
}
static int tcmu_set_max_blocks_param(struct tcmu_dev *udev, substring_t *arg)
{
int val, ret;
ret = match_int(arg, &val);
if (ret < 0) {
pr_err("match_int() failed for max_data_area_mb=. Error %d.\n",
ret);
return ret;
}
if (val <= 0) {
pr_err("Invalid max_data_area %d.\n", val);
return -EINVAL;
}
mutex_lock(&udev->cmdr_lock);
if (udev->data_bitmap) {
pr_err("Cannot set max_data_area_mb after it has been enabled.\n");
ret = -EINVAL;
goto unlock;
}
udev->max_blocks = TCMU_MBS_TO_BLOCKS(val);
if (udev->max_blocks > tcmu_global_max_blocks) {
pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
val, TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
udev->max_blocks = tcmu_global_max_blocks;
}
unlock:
mutex_unlock(&udev->cmdr_lock);
return ret;
}
static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
const char *page, ssize_t count)
{
struct tcmu_dev *udev = TCMU_DEV(dev);
char *orig, *ptr, *opts, *arg_p;
substring_t args[MAX_OPT_ARGS];
int ret = 0, token, tmpval;
int ret = 0, token;
opts = kstrdup(page, GFP_KERNEL);
if (!opts)
@ -2105,37 +2142,7 @@ static ssize_t tcmu_set_configfs_dev_params(struct se_device *dev,
pr_err("kstrtoint() failed for nl_reply_supported=\n");
break;
case Opt_max_data_area_mb:
if (dev->export_count) {
pr_err("Unable to set max_data_area_mb while exports exist\n");
ret = -EINVAL;
break;
}
arg_p = match_strdup(&args[0]);
if (!arg_p) {
ret = -ENOMEM;
break;
}
ret = kstrtoint(arg_p, 0, &tmpval);
kfree(arg_p);
if (ret < 0) {
pr_err("kstrtoint() failed for max_data_area_mb=\n");
break;
}
if (tmpval <= 0) {
pr_err("Invalid max_data_area %d\n", tmpval);
ret = -EINVAL;
break;
}
udev->max_blocks = TCMU_MBS_TO_BLOCKS(tmpval);
if (udev->max_blocks > tcmu_global_max_blocks) {
pr_err("%d is too large. Adjusting max_data_area_mb to global limit of %u\n",
tmpval,
TCMU_BLOCKS_TO_MBS(tcmu_global_max_blocks));
udev->max_blocks = tcmu_global_max_blocks;
}
ret = tcmu_set_max_blocks_param(udev, &args[0]);
break;
default:
break;