From: Mel Gorman Date: Mon, 29 Jun 2020 14:41:45 +0000 (+0100) Subject: Revert "fs: Do not check if there is a fsnotify watcher on pseudo inodes" X-Git-Tag: v5.10.7~2220 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b6509f6a8c4313c068c69785c001451415969e44;p=platform%2Fkernel%2Flinux-rpi.git Revert "fs: Do not check if there is a fsnotify watcher on pseudo inodes" This reverts commit e9c15badbb7b ("fs: Do not check if there is a fsnotify watcher on pseudo inodes"). The commit intended to eliminate fsnotify-related overhead for pseudo inodes but it is broken in concept. inotify can receive events of pipe files under /proc/X/fd and chromium relies on close and open events for sandboxing. Maxim Levitsky reported the following Chromium starts as a white rectangle, shows few white rectangles that resemble its notifications and then crashes. The stdout output from chromium: [mlevitsk@starship ~]$chromium-freeworld mesa: for the --simplifycfg-sink-common option: may only occur zero or one times! mesa: for the --global-isel-abort option: may only occur zero or one times! [3379:3379:0628/135151.440930:ERROR:browser_switcher_service.cc(238)] XXX Init() ../../sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.cc:**CRASHING**:seccomp-bpf failure in syscall 0072 Received signal 11 SEGV_MAPERR 0000004a9048 Crashes are not universal but even if chromium does not crash, it certainly does not work properly. While filtering just modify and access might be safe, the benefit is not worth the risk hence the revert. Reported-by: Maxim Levitsky Fixes: e9c15badbb7b ("fs: Do not check if there is a fsnotify watcher on pseudo inodes") Signed-off-by: Mel Gorman Signed-off-by: Linus Torvalds --- diff --git a/fs/file_table.c b/fs/file_table.c index 6560350..656647f 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -230,7 +230,7 @@ struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt, d_set_d_op(path.dentry, &anon_ops); path.mnt = mntget(mnt); d_instantiate(path.dentry, inode); - file = alloc_file(&path, flags | FMODE_NONOTIFY, fops); + file = alloc_file(&path, flags, fops); if (IS_ERR(file)) { ihold(inode); path_put(&path);