This is a note to let you know that I've just added the patch titled tracefs: Zero out the tracefs_inode when allocating it 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: tracefs-zero-out-the-tracefs_inode-when-allocating-it.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 13:10:43 2024 From: Steven Rostedt <rostedt@xxxxxxxxxxx> Date: Tue, 06 Feb 2024 07:09:52 -0500 Subject: tracefs: Zero out the tracefs_inode when allocating it 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>, Christian Brauner <brauner@xxxxxxxxxx>, Al Viro <viro@xxxxxxxxxxxxxxxxxx>, Ajay Kaher <ajay.kaher@xxxxxxxxxxxx>, kernel test robot <oliver.sang@xxxxxxxxx> Message-ID: <20240206120954.038732037@xxxxxxxxxxxxxxxxxxxxx> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx> commit d81786f53aec14fd4d56263145a0635afbc64617 upstream. eventfs uses the tracefs_inode and assumes that it's already initialized to zero. That is, it doesn't set fields to zero (like ti->private) after getting its tracefs_inode. This causes bugs due to stale values. Just initialize the entire structure to zero on allocation so there isn't any more surprises. This is a partial fix to access to ti->private. The assignment still needs to be made before the dentry is instantiated. Link: https://lore.kernel.org/linux-trace-kernel/20240131185512.315825944@xxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Cc: Christian Brauner <brauner@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Ajay Kaher <ajay.kaher@xxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode") Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> Closes: https://lore.kernel.org/oe-lkp/202401291043.e62e89dc-oliver.sang@xxxxxxxxx Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/tracefs/inode.c | 6 ++++-- fs/tracefs/internal.h | 3 ++- 2 files changed, 6 insertions(+), 3 deletions(-) --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -38,8 +38,6 @@ static struct inode *tracefs_alloc_inode if (!ti) return NULL; - ti->flags = 0; - return &ti->vfs_inode; } @@ -779,7 +777,11 @@ static void init_once(void *foo) { struct tracefs_inode *ti = (struct tracefs_inode *) foo; + /* inode_init_once() calls memset() on the vfs_inode portion */ inode_init_once(&ti->vfs_inode); + + /* Zero out the rest */ + memset_after(ti, 0, vfs_inode); } static int __init tracefs_init(void) --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -11,9 +11,10 @@ enum { }; struct tracefs_inode { + struct inode vfs_inode; + /* The below gets initialized with memset_after(ti, 0, vfs_inode) */ unsigned long flags; void *private; - struct inode vfs_inode; }; /* 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