From: Amir Goldstein <amir73il@gmail.com> mainline inclusion from mainline-v6.8-rc5 commit 853b8d7597eea4ccaaefbcf0942cd42fc86d542a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBHLU4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- commit dfad37051ade ("remap_range: move permission hooks out of do_clone_file_range()") moved the permission hooks from do_clone_file_range() out to its caller vfs_clone_file_range(), but left all the fast sanity checks in do_clone_file_range(). This makes the expensive security hooks be called in situations that they would not have been called before (e.g. fs does not support clone). The only reason for the do_clone_file_range() helper was that overlayfs did not use to be able to call vfs_clone_file_range() from copy up context with sb_writers lock held. However, since commit c63e56a4a652 ("ovl: do not open/llseek lower file with upper sb_writers held"), overlayfs just uses an open coded version of vfs_clone_file_range(). Merge_clone_file_range() into vfs_clone_file_range(), restoring the original order of checks as it was before the regressing commit and adapt the overlayfs code to call vfs_clone_file_range() before the permission hooks that were added by commit ca7ab482401c ("ovl: add permission hooks outside of do_splice_direct()"). Note that in the merge of do_clone_file_range(), the file_start_write() context was reduced to cover ->remap_file_range() without holding it over the permission hooks, which was the reason for doing the regressing commit in the first place. Reported-and-tested-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202401312229.eddeb9a6-oliver.sang@intel.com Fixes: dfad37051ade ("remap_range: move permission hooks out of do_clone_file_range()") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20240202102258.1582671-1-amir73il@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- include/linux/fs.h | 3 --- fs/overlayfs/copy_up.c | 14 ++++++-------- fs/remap_range.c | 31 +++++++++---------------------- 3 files changed, 15 insertions(+), 33 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 9dc42354a781..d2b0534fe85f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2166,9 +2166,6 @@ int __generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, loff_t *count, unsigned int remap_flags); -extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t len, unsigned int remap_flags); extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, loff_t len, unsigned int remap_flags); diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 5da41eba056d..d02b4e3ae724 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -265,20 +265,18 @@ static int ovl_copy_up_file(struct ovl_fs *ofs, struct dentry *dentry, if (IS_ERR(old_file)) return PTR_ERR(old_file); + /* Try to use clone_file_range to clone up within the same fs */ + cloned = vfs_clone_file_range(old_file, 0, new_file, 0, len, 0); + if (cloned == len) + goto out_fput; + + /* Couldn't clone, so now we try to copy the data */ 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); - ovl_end_write(dentry); - if (cloned == len) - goto out_fput; - /* Couldn't clone, so now we try to copy the data */ - /* Check if lower fs supports seek operation */ if (old_file->f_mode & FMODE_LSEEK) skip_hole = true; diff --git a/fs/remap_range.c b/fs/remap_range.c index 12131f2a6c9e..cd4dbc11125f 100644 --- a/fs/remap_range.c +++ b/fs/remap_range.c @@ -367,9 +367,9 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, } EXPORT_SYMBOL(generic_remap_file_range_prep); -loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t len, unsigned int remap_flags) +loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + loff_t len, unsigned int remap_flags) { loff_t ret; @@ -385,23 +385,6 @@ loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, if (!file_in->f_op->remap_file_range) return -EOPNOTSUPP; - ret = file_in->f_op->remap_file_range(file_in, pos_in, - file_out, pos_out, len, remap_flags); - if (ret < 0) - return ret; - - fsnotify_access(file_in); - fsnotify_modify(file_out); - return ret; -} -EXPORT_SYMBOL(do_clone_file_range); - -loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t len, unsigned int remap_flags) -{ - loff_t ret; - ret = remap_verify_area(file_in, pos_in, len, false); if (ret) return ret; @@ -411,10 +394,14 @@ loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, return ret; file_start_write(file_out); - ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len, - remap_flags); + ret = file_in->f_op->remap_file_range(file_in, pos_in, + file_out, pos_out, len, remap_flags); file_end_write(file_out); + if (ret < 0) + return ret; + fsnotify_access(file_in); + fsnotify_modify(file_out); return ret; } EXPORT_SYMBOL(vfs_clone_file_range); -- 2.39.2