This is a note to let you know that I've just added the patch titled eventfs: Have event files and directories default to parent uid and gid 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-have-event-files-and-directories-default-to-parent-uid-and-gid.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 13:09:23 2024 From: Steven Rostedt <rostedt@xxxxxxxxxxx> Date: Tue, 06 Feb 2024 07:09:36 -0500 Subject: eventfs: Have event files and directories default to parent uid and gid 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>, Hongyu Jin <hongyu.jin@xxxxxxxxxx>, Dongliang Cui <cuidongliang390@xxxxxxxxx> Message-ID: <20240206120951.415245327@xxxxxxxxxxxxxxxxxxxxx> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> commit 0dfc852b6fe3cbecbea67332a0dce2bebeba540d upstream. Dongliang reported: I found that in the latest version, the nodes of tracefs have been changed to dynamically created. This has caused me to encounter a problem where the gid I specified in the mounting parameters cannot apply to all files, as in the following situation: /data/tmp/events # mount | grep tracefs tracefs on /data/tmp type tracefs (rw,seclabel,relatime,gid=3012) gid 3012 = readtracefs /data/tmp # ls -lh total 0 -r--r----- 1 root readtracefs 0 1970-01-01 08:00 README -r--r----- 1 root readtracefs 0 1970-01-01 08:00 available_events ums9621_1h10:/data/tmp/events # ls -lh total 0 drwxr-xr-x 2 root root 0 2023-12-19 00:56 alarmtimer drwxr-xr-x 2 root root 0 2023-12-19 00:56 asoc It will prevent certain applications from accessing tracefs properly, I try to avoid this issue by making the following modifications. To fix this, have the files created default to taking the ownership of the parent dentry unless the ownership was previously set by the user. Link: https://lore.kernel.org/linux-trace-kernel/1703063706-30539-1-git-send-email-dongliang.cui@xxxxxxxxxx/ Link: https://lore.kernel.org/linux-trace-kernel/20231220105017.1489d790@xxxxxxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Cc: Hongyu Jin <hongyu.jin@xxxxxxxxxx> Fixes: 28e12c09f5aa0 ("eventfs: Save ownership and mode") Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Reported-by: Dongliang Cui <cuidongliang390@xxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/tracefs/event_inode.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -148,7 +148,8 @@ static const struct file_operations even .release = eventfs_release, }; -static void update_inode_attr(struct inode *inode, struct eventfs_attr *attr, umode_t mode) +static void update_inode_attr(struct dentry *dentry, struct inode *inode, + struct eventfs_attr *attr, umode_t mode) { if (!attr) { inode->i_mode = mode; @@ -162,9 +163,13 @@ static void update_inode_attr(struct ino if (attr->mode & EVENTFS_SAVE_UID) inode->i_uid = attr->uid; + else + inode->i_uid = d_inode(dentry->d_parent)->i_uid; if (attr->mode & EVENTFS_SAVE_GID) inode->i_gid = attr->gid; + else + inode->i_gid = d_inode(dentry->d_parent)->i_gid; } /** @@ -206,7 +211,7 @@ static struct dentry *create_file(const return eventfs_failed_creating(dentry); /* If the user updated the directory's attributes, use them */ - update_inode_attr(inode, attr, mode); + update_inode_attr(dentry, inode, attr, mode); inode->i_op = &eventfs_file_inode_operations; inode->i_fop = fop; @@ -242,7 +247,8 @@ static struct dentry *create_dir(struct return eventfs_failed_creating(dentry); /* If the user updated the directory's attributes, use them */ - update_inode_attr(inode, &ei->attr, S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO); + update_inode_attr(dentry, inode, &ei->attr, + S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO); inode->i_op = &eventfs_root_dir_inode_operations; inode->i_fop = &eventfs_file_operations; 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