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| author | Li Zefan <lizf@cn.fujitsu.com> | 2011-06-08 08:27:56 +0000 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2011-06-10 18:57:10 -0400 |
| commit | 027ed2f0044e95a97ed34db2d55a9ca95ba84385 (patch) | |
| tree | 7bcdb6d542e5adbbe8cfd59c9ddc36be868f1238 | |
| parent | 9eb9104c665aae2401a1723c044669eb10240072 (diff) | |
| download | lwn-027ed2f0044e95a97ed34db2d55a9ca95ba84385.tar.gz lwn-027ed2f0044e95a97ed34db2d55a9ca95ba84385.zip | |
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.c | 23 |
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) |