diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2013-12-11 23:07:51 -0500 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-01-25 03:13:03 -0500 |
commit | 1c1c8747cd0528fe1d225badf25bf5346d799ea3 (patch) | |
tree | 05de87ea5f6268946abfe39c26770d65a7c4373e /fs | |
parent | 208adb6403e079ceeb8e731696615d22db6f397b (diff) |
btrfs: sanitize BTRFS_IOC_FILE_EXTENT_SAME
* don't assume that ->dest_count won't change between copy_from_user()
and memdup_user()
* use fdget instead of fget
* don't bother comparing superblocks when we'd already compared vfsmounts
* get rid of excessive goto
* use file_inode() instead of open-coding the sucker
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/btrfs/ioctl.c | 70 |
1 files changed, 24 insertions, 46 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 21da5762b0b..ad27dcea319 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -2686,14 +2686,11 @@ out_unlock: #define BTRFS_MAX_DEDUPE_LEN (16 * 1024 * 1024) static long btrfs_ioctl_file_extent_same(struct file *file, - void __user *argp) + struct btrfs_ioctl_same_args __user *argp) { - struct btrfs_ioctl_same_args tmp; struct btrfs_ioctl_same_args *same; struct btrfs_ioctl_same_extent_info *info; - struct inode *src = file->f_dentry->d_inode; - struct file *dst_file = NULL; - struct inode *dst; + struct inode *src = file_inode(file); u64 off; u64 len; int i; @@ -2701,6 +2698,7 @@ static long btrfs_ioctl_file_extent_same(struct file *file, unsigned long size; u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize; bool is_admin = capable(CAP_SYS_ADMIN); + u16 count; if (!(file->f_mode & FMODE_READ)) return -EINVAL; @@ -2709,17 +2707,14 @@ static long btrfs_ioctl_file_extent_same(struct file *file, if (ret) return ret; - if (copy_from_user(&tmp, - (struct btrfs_ioctl_same_args __user *)argp, - sizeof(tmp))) { + if (get_user(count, &argp->dest_count)) { ret = -EFAULT; goto out; } - size = sizeof(tmp) + - tmp.dest_count * sizeof(struct btrfs_ioctl_same_extent_info); + size = offsetof(struct btrfs_ioctl_same_args __user, info[count]); - same = memdup_user((struct btrfs_ioctl_same_args __user *)argp, size); + same = memdup_user(argp, size); if (IS_ERR(same)) { ret = PTR_ERR(same); @@ -2756,52 +2751,35 @@ static long btrfs_ioctl_file_extent_same(struct file *file, goto out; /* pre-format output fields to sane values */ - for (i = 0; i < same->dest_count; i++) { + for (i = 0; i < count; i++) { same->info[i].bytes_deduped = 0ULL; same->info[i].status = 0; } - ret = 0; - for (i = 0; i < same->dest_count; i++) { - info = &same->info[i]; - - dst_file = fget(info->fd); - if (!dst_file) { + for (i = 0, info = same->info; i < count; i++, info++) { + struct inode *dst; + struct fd dst_file = fdget(info->fd); + if (!dst_file.file) { info->status = -EBADF; - goto next; + continue; } + dst = file_inode(dst_file.file); - if (!(is_admin || (dst_file->f_mode & FMODE_WRITE))) { + if (!(is_admin || (dst_file.file->f_mode & FMODE_WRITE))) { info->status = -EINVAL; - goto next; - } - - info->status = -EXDEV; - if (file->f_path.mnt != dst_file->f_path.mnt) - goto next; - - dst = dst_file->f_dentry->d_inode; - if (src->i_sb != dst->i_sb) - goto next; - - if (S_ISDIR(dst->i_mode)) { + } else if (file->f_path.mnt != dst_file.file->f_path.mnt) { + info->status = -EXDEV; + } else if (S_ISDIR(dst->i_mode)) { info->status = -EISDIR; - goto next; - } - - if (!S_ISREG(dst->i_mode)) { + } else if (!S_ISREG(dst->i_mode)) { info->status = -EACCES; - goto next; + } else { + info->status = btrfs_extent_same(src, off, len, dst, + info->logical_offset); + if (info->status == 0) + info->bytes_deduped += len; } - - info->status = btrfs_extent_same(src, off, len, dst, - info->logical_offset); - if (info->status == 0) - info->bytes_deduped += len; - -next: - if (dst_file) - fput(dst_file); + fdput(dst_file); } ret = copy_to_user(argp, same, size); |