diff options
| -rw-r--r-- | fs/overlayfs/copy_up.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 4382881b0709..106f8643af3b 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -230,6 +230,19 @@ static int ovl_copy_fileattr(struct inode *inode, const struct path *old, return ovl_real_fileattr_set(new, &newfa); } +static int ovl_verify_area(loff_t pos, loff_t pos2, loff_t len, loff_t totlen) +{ + loff_t tmp; + + if (WARN_ON_ONCE(pos != pos2)) + return -EIO; + if (WARN_ON_ONCE(pos < 0 || len < 0 || totlen < 0)) + return -EIO; + if (WARN_ON_ONCE(check_add_overflow(pos, len, &tmp))) + return -EIO; + return 0; +} + static int ovl_copy_up_file(struct ovl_fs *ofs, struct dentry *dentry, struct file *new_file, loff_t len) { @@ -244,13 +257,20 @@ static int ovl_copy_up_file(struct ovl_fs *ofs, struct dentry *dentry, int error = 0; ovl_path_lowerdata(dentry, &datapath); - if (WARN_ON(datapath.dentry == NULL)) + if (WARN_ON_ONCE(datapath.dentry == NULL) || + WARN_ON_ONCE(len < 0)) return -EIO; old_file = ovl_path_open(&datapath, O_LARGEFILE | O_RDONLY); if (IS_ERR(old_file)) return PTR_ERR(old_file); + error = rw_verify_area(READ, old_file, &old_pos, len); + if (!error) + error = rw_verify_area(WRITE, new_file, &new_pos, len); + if (error) + goto out_fput; + /* Try to use clone_file_range to clone up within the same fs */ ovl_start_write(dentry); cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0); @@ -309,6 +329,10 @@ static int ovl_copy_up_file(struct ovl_fs *ofs, struct dentry *dentry, } } + error = ovl_verify_area(old_pos, new_pos, this_len, len); + if (error) + break; + ovl_start_write(dentry); bytes = do_splice_direct(old_file, &old_pos, new_file, &new_pos, |