This is a note to let you know that I've just added the patch titled eventfs: Do not allow NULL parent to eventfs_start_creating() to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: eventfs-do-not-allow-null-parent-to-eventfs_start_creating.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From SRS0=eEWY=JP=rostedt.homelinux.com=rostedt@xxxxxxxxxx Tue Feb 6 13:10:53 2024 From: Steven Rostedt <rostedt@xxxxxxxxxxx> Date: Tue, 06 Feb 2024 07:09:33 -0500 Subject: eventfs: Do not allow NULL parent to eventfs_start_creating() To: linux-kernel@xxxxxxxxxxxxxxx, stable@xxxxxxxxxxxxxxx Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, Sasha Levin <sashal@xxxxxxxxxx>, Masami Hiramatsu <mhiramat@xxxxxxxxxx>, Mark Rutland <mark.rutland@xxxxxxx>, Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, Josef Bacik <josef@xxxxxxxxxxxxxx> Message-ID: <20240206120950.930155940@xxxxxxxxxxxxxxxxxxxxx> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> commit fc4561226feaad5fcdcb55646c348d77b8ee69c5 upstream. The eventfs directory is dynamically created via the meta data supplied by the existing trace events. All files and directories in eventfs has a parent. Do not allow NULL to be passed into eventfs_start_creating() as the parent because that should never happen. Warn if it does. Link: https://lkml.kernel.org/r/20231121231112.693841807@xxxxxxxxxxx Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/tracefs/inode.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -509,20 +509,15 @@ struct dentry *eventfs_start_creating(co struct dentry *dentry; int error; + /* Must always have a parent. */ + if (WARN_ON_ONCE(!parent)) + return ERR_PTR(-EINVAL); + error = simple_pin_fs(&trace_fs_type, &tracefs_mount, &tracefs_mount_count); if (error) return ERR_PTR(error); - /* - * If the parent is not specified, we create it in the root. - * We need the root dentry to do this, which is in the super - * block. A pointer to that is in the struct vfsmount that we - * have around. - */ - if (!parent) - parent = tracefs_mount->mnt_root; - if (unlikely(IS_DEADDIR(parent->d_inode))) dentry = ERR_PTR(-ENOENT); else Patches currently in stable-queue which might be from rostedt@xxxxxxxxxx are queue-6.6/eventfs-keep-all-directory-links-at-1.patch queue-6.6/eventfs-make-sure-that-parent-d_inode-is-locked-in-creating-files-dirs.patch queue-6.6/eventfs-save-directory-inodes-in-the-eventfs_inode-structure.patch queue-6.6/revert-eventfs-save-ownership-and-mode.patch queue-6.6/tracefs-zero-out-the-tracefs_inode-when-allocating-it.patch queue-6.6/eventfs-read-ei-entries-before-ei-children-in-eventfs_iterate.patch queue-6.6/eventfs-do-not-invalidate-dentry-in-create_file-dir_dentry.patch queue-6.6/eventfs-fix-file-and-directory-uid-and-gid-ownership.patch queue-6.6/eventfs-remove-lookup-parameter-from-create_dir-file_dentry.patch queue-6.6/eventfs-use-gfp_nofs-for-allocation-when-eventfs_mutex-is-held.patch queue-6.6/eventfs-remove-fsnotify-functions-from-lookup.patch queue-6.6/eventfs-use-err_cast-in-eventfs_create_events_dir.patch queue-6.6/revert-eventfs-use-simple_recursive_removal-to-clean-up-dentries.patch queue-6.6/eventfs-use-simple_recursive_removal-to-clean-up-dentries.patch queue-6.6/eventfs-stop-using-dcache_readdir-for-getdents.patch queue-6.6/eventfs-have-event-files-and-directories-default-to-parent-uid-and-gid.patch queue-6.6/eventfs-use-eventfs_remove_events_dir.patch queue-6.6/eventfs-delete-eventfs_inode-when-the-last-dentry-is-freed.patch queue-6.6/tracefs-avoid-using-the-ei-dentry-pointer-unnecessarily.patch queue-6.6/tracefs-remove-stale-update_gid-code.patch queue-6.6/eventfs-initialize-the-tracefs-inode-properly.patch queue-6.6/eventfs-remove-special-processing-of-dput-of-events-directory.patch queue-6.6/eventfs-save-ownership-and-mode.patch queue-6.6/tracefs-check-for-dentry-d_inode-exists-in-set_gid.patch queue-6.6/eventfs-do-ctx-pos-update-for-all-iterations-in-eventfs_iterate.patch queue-6.6/tracefs-dentry-lookup-crapectomy.patch queue-6.6/eventfs-move-taking-of-inode_lock-into-dcache_dir_open_wrapper.patch queue-6.6/eventfs-have-a-free_ei-that-just-frees-the-eventfs_inode.patch queue-6.6/revert-eventfs-remove-is_freed-union-with-rcu-head.patch queue-6.6/eventfs-have-the-inodes-all-for-files-and-directories-all-be-the-same.patch queue-6.6/eventfs-use-kcalloc-instead-of-kzalloc.patch queue-6.6/eventfs-test-for-ei-is_freed-when-accessing-ei-dentry.patch queue-6.6/eventfs-fix-bitwise-fields-for-is_events.patch queue-6.6/eventfs-fix-warn_on-in-create_file_dentry.patch queue-6.6/eventfs-fix-events-beyond-name_max-blocking-tasks.patch queue-6.6/eventfs-shortcut-eventfs_iterate-by-skipping-entries-already-read.patch queue-6.6/revert-eventfs-do-not-allow-null-parent-to-eventfs_start_creating.patch queue-6.6/eventfs-do-not-allow-null-parent-to-eventfs_start_creating.patch queue-6.6/eventfs-do-not-create-dentries-nor-inodes-in-iterate_shared.patch queue-6.6/eventfs-have-eventfs_iterate-stop-immediately-if-ei-is_freed-is-set.patch queue-6.6/eventfs-fix-typo-in-eventfs_inode-union-comment.patch queue-6.6/eventfs-remove-expectation-that-ei-is_freed-means-ei-dentry-null.patch queue-6.6/eventfs-restructure-eventfs_inode-structure-to-be-more-condensed.patch queue-6.6/eventfs-warn-if-an-eventfs_inode-is-freed-without-is_freed-being-set.patch queue-6.6/eventfs-get-rid-of-dentry-pointers-without-refcounts.patch queue-6.6/eventfs-remove-unused-d_parent-pointer-field.patch queue-6.6/eventfs-hold-eventfs_mutex-when-calling-callback-functions.patch queue-6.6/eventfs-remove-is_freed-union-with-rcu-head.patch queue-6.6/tracefs-eventfs-modify-mismatched-function-name.patch queue-6.6/eventfs-fix-kerneldoc-of-eventfs_remove_rec.patch queue-6.6/tracefs-eventfs-use-root-and-instance-inodes-as-default-ownership.patch queue-6.6/revert-eventfs-check-for-null-ef-in-eventfs_set_attr.patch queue-6.6/eventfs-fix-failure-path-in-eventfs_create_events_dir.patch queue-6.6/eventfs-clean-up-dentry-ops-and-add-revalidate-function.patch