diff options
Diffstat (limited to 'fs/overlayfs/file.c')
-rw-r--r-- | fs/overlayfs/file.c | 149 |
1 files changed, 24 insertions, 125 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index efccb7c1f9bc..077d3ad343f6 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -53,9 +53,10 @@ static struct file *ovl_open_realfile(const struct file *file, err = inode_permission(realinode, MAY_OPEN | acc_mode); if (err) { realfile = ERR_PTR(err); - } else if (!inode_owner_or_capable(realinode)) { - realfile = ERR_PTR(-EPERM); } else { + if (!inode_owner_or_capable(realinode)) + flags &= ~O_NOATIME; + realfile = open_with_fake_path(&file->f_path, flags, realinode, current_cred()); } @@ -75,12 +76,6 @@ static int ovl_change_flags(struct file *file, unsigned int flags) struct inode *inode = file_inode(file); int err; - flags |= OVL_OPEN_FLAGS; - - /* If some flag changed that cannot be changed then something's amiss */ - if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK)) - return -EIO; - flags &= OVL_SETFL_MASK; if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode)) @@ -397,56 +392,15 @@ out_unlock: return ret; } -static ssize_t ovl_splice_read(struct file *in, loff_t *ppos, - struct pipe_inode_info *pipe, size_t len, - unsigned int flags) -{ - ssize_t ret; - struct fd real; - const struct cred *old_cred; - - ret = ovl_real_fdget(in, &real); - if (ret) - return ret; - - old_cred = ovl_override_creds(file_inode(in)->i_sb); - ret = generic_file_splice_read(real.file, ppos, pipe, len, flags); - revert_creds(old_cred); - - ovl_file_accessed(in); - fdput(real); - return ret; -} - -static ssize_t -ovl_splice_write(struct pipe_inode_info *pipe, struct file *out, - loff_t *ppos, size_t len, unsigned int flags) -{ - struct fd real; - const struct cred *old_cred; - ssize_t ret; - - ret = ovl_real_fdget(out, &real); - if (ret) - return ret; - - old_cred = ovl_override_creds(file_inode(out)->i_sb); - ret = iter_file_splice_write(pipe, real.file, ppos, len, flags); - revert_creds(old_cred); - - ovl_file_accessed(out); - fdput(real); - return ret; -} - static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) { struct fd real; const struct cred *old_cred; int ret; - if (!ovl_should_sync(OVL_FS(file_inode(file)->i_sb))) - return 0; + ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb)); + if (ret <= 0) + return ret; ret = ovl_real_fdget_meta(file, &real, !datasync); if (ret) @@ -541,46 +495,31 @@ static long ovl_real_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct fd real; - const struct cred *old_cred; long ret; ret = ovl_real_fdget(file, &real); if (ret) return ret; - old_cred = ovl_override_creds(file_inode(file)->i_sb); ret = security_file_ioctl(real.file, cmd, arg); - if (!ret) + if (!ret) { + /* + * Don't override creds, since we currently can't safely check + * permissions before doing so. + */ ret = vfs_ioctl(real.file, cmd, arg); - revert_creds(old_cred); + } fdput(real); return ret; } -static unsigned int ovl_iflags_to_fsflags(unsigned int iflags) -{ - unsigned int flags = 0; - - if (iflags & S_SYNC) - flags |= FS_SYNC_FL; - if (iflags & S_APPEND) - flags |= FS_APPEND_FL; - if (iflags & S_IMMUTABLE) - flags |= FS_IMMUTABLE_FL; - if (iflags & S_NOATIME) - flags |= FS_NOATIME_FL; - - return flags; -} - static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd, - unsigned long arg, unsigned int flags) + unsigned long arg) { long ret; struct inode *inode = file_inode(file); - unsigned int oldflags; if (!inode_owner_or_capable(inode)) return -EACCES; @@ -591,10 +530,13 @@ static long ovl_ioctl_set_flags(struct file *file, unsigned int cmd, inode_lock(inode); - /* Check the capability before cred override */ - oldflags = ovl_iflags_to_fsflags(READ_ONCE(inode->i_flags)); - ret = vfs_ioc_setflags_prepare(inode, oldflags, flags); - if (ret) + /* + * Prevent copy up if immutable and has no CAP_LINUX_IMMUTABLE + * capability. + */ + ret = -EPERM; + if (!ovl_has_upperdata(inode) && IS_IMMUTABLE(inode) && + !capable(CAP_LINUX_IMMUTABLE)) goto unlock; ret = ovl_maybe_copy_up(file_dentry(file), O_WRONLY); @@ -613,46 +555,6 @@ unlock: } -static long ovl_ioctl_set_fsflags(struct file *file, unsigned int cmd, - unsigned long arg) -{ - unsigned int flags; - - if (get_user(flags, (int __user *) arg)) - return -EFAULT; - - return ovl_ioctl_set_flags(file, cmd, arg, flags); -} - -static unsigned int ovl_fsxflags_to_fsflags(unsigned int xflags) -{ - unsigned int flags = 0; - - if (xflags & FS_XFLAG_SYNC) - flags |= FS_SYNC_FL; - if (xflags & FS_XFLAG_APPEND) - flags |= FS_APPEND_FL; - if (xflags & FS_XFLAG_IMMUTABLE) - flags |= FS_IMMUTABLE_FL; - if (xflags & FS_XFLAG_NOATIME) - flags |= FS_NOATIME_FL; - - return flags; -} - -static long ovl_ioctl_set_fsxflags(struct file *file, unsigned int cmd, - unsigned long arg) -{ - struct fsxattr fa; - - memset(&fa, 0, sizeof(fa)); - if (copy_from_user(&fa, (void __user *) arg, sizeof(fa))) - return -EFAULT; - - return ovl_ioctl_set_flags(file, cmd, arg, - ovl_fsxflags_to_fsflags(fa.fsx_xflags)); -} - long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { long ret; @@ -663,12 +565,9 @@ long ovl_ioctl(struct file *file, unsigned int cmd, unsigned long arg) ret = ovl_real_ioctl(file, cmd, arg); break; - case FS_IOC_SETFLAGS: - ret = ovl_ioctl_set_fsflags(file, cmd, arg); - break; - case FS_IOC_FSSETXATTR: - ret = ovl_ioctl_set_fsxflags(file, cmd, arg); + case FS_IOC_SETFLAGS: + ret = ovl_ioctl_set_flags(file, cmd, arg); break; default: @@ -801,8 +700,8 @@ const struct file_operations ovl_file_operations = { #ifdef CONFIG_COMPAT .compat_ioctl = ovl_compat_ioctl, #endif - .splice_read = ovl_splice_read, - .splice_write = ovl_splice_write, + .splice_read = generic_file_splice_read, + .splice_write = iter_file_splice_write, .copy_file_range = ovl_copy_file_range, .remap_file_range = ovl_remap_file_range, |