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authorLi Zefan <lizf@cn.fujitsu.com>2011-06-08 08:27:56 +0000
committerChris Mason <chris.mason@oracle.com>2011-06-10 18:57:10 -0400
commit027ed2f0044e95a97ed34db2d55a9ca95ba84385 (patch)
tree7bcdb6d542e5adbbe8cfd59c9ddc36be868f1238
parent9eb9104c665aae2401a1723c044669eb10240072 (diff)
Btrfs: avoid stack bloat in btrfs_ioctl_fs_info()
The size of struct btrfs_ioctl_fs_info_args is as big as 1KB, so don't declare the variable on stack. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Reviewed-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
-rw-r--r--fs/btrfs/ioctl.c23
1 files changed, 14 insertions, 9 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ac37040e426a..b793d112d1f6 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2054,29 +2054,34 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
static long btrfs_ioctl_fs_info(struct btrfs_root *root, void __user *arg)
{
- struct btrfs_ioctl_fs_info_args fi_args;
+ struct btrfs_ioctl_fs_info_args *fi_args;
struct btrfs_device *device;
struct btrfs_device *next;
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
+ int ret = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- fi_args.num_devices = fs_devices->num_devices;
- fi_args.max_id = 0;
- memcpy(&fi_args.fsid, root->fs_info->fsid, sizeof(fi_args.fsid));
+ fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
+ if (!fi_args)
+ return -ENOMEM;
+
+ fi_args->num_devices = fs_devices->num_devices;
+ memcpy(&fi_args->fsid, root->fs_info->fsid, sizeof(fi_args->fsid));
mutex_lock(&fs_devices->device_list_mutex);
list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
- if (device->devid > fi_args.max_id)
- fi_args.max_id = device->devid;
+ if (device->devid > fi_args->max_id)
+ fi_args->max_id = device->devid;
}
mutex_unlock(&fs_devices->device_list_mutex);
- if (copy_to_user(arg, &fi_args, sizeof(fi_args)))
- return -EFAULT;
+ if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
+ ret = -EFAULT;
- return 0;
+ kfree(fi_args);
+ return ret;
}
static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)