From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794272730; b=2gBDN64U9514SROucwHn8INqftf9KjOsNHgis41NpKAeFmM0YtSgiDiLg2DDe4lp6M9a Qd52AS/Il/kUE+ifwerRY02BGspEi1+q8MmoW+iO/NfgVczFZw35k/mcLkQMYF24RVz+t B5hyT94oCrk7DTfptjEISEChq3s9uLu6Io+KZxfbeE33KEk3ozQG5xkaedeMgRhhGo3qV NPnZhpnNeWZ+Z/y9JPjouOU6Y+6p8XW8eQoGfaIICJOnBzB0jn4WSDXUh82Hjqprk+mvu URM49/LbWInk0ZzAw7mzPeZUH0b4b0lZ+hP5j6S2Ivj+PbXGHL4xNFcb2HjfCqhnWNA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794272730; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=/FMDXfMW1EDs8C5TEtA82Bi/KkCgWErFIPpsaSS7az8=; b=z/PQeww/gSj83RzXTtvV0ygc4VSEpmd6+w+oi3+320RsVy/KVGqh9tBYQCBd+aw1KTLW vJtmzN6E2ZsIG5q8WBiEVjRIKZ3FmwoH23kPgP4Y+Cb7bzRVro+E+OhcNzy0uy0Y5Ic/J vQa4kqRNL+LVB0y5qv3vr7hJpwgruOyXZmsVQ8JsdVsAm8QCd49O5iNXxeicRWT1Vl3ss juGlemFBNjYtGXXY4/Oz3ukVjOu4VoZKqcxe+nXG8tn5vxt1wRNVtZlObEBF8sCltfOX8 CPDcapaWGFDGn6qtfBEBD35+iiEa6qwqGFV8Nsw7KuXTxDrb4z/lqXAxeJEy7bS6p7Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MK8+E1gd; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D9FF9606A31C for ; Tue, 10 Nov 2026 01:05:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MK8+E1gd Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36B201F0089F; Tue, 10 Nov 2026 01:05:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794272729; bh=/FMDXfMW1EDs8C5TEtA82Bi/KkCgWErFIPpsaSS7az8=; h=From:To:Cc:Subject:Date; b=MK8+E1gdk2eUbxqWrNH7LB6rXvfht3UIL4rFVT1KtuNXGrnT4oNIIkSFrkoQgxRhB 4Pv9VH8nw87GJM1mxSyQ5ohCpK1F2pNN2vigcDMpqPwKtnkdM7L9R4ugzFjXsH63z0 1ieM+59En5ITE67dPWpRL5AsS4BivmGa8hDKOnAWMpN6Pma1hfHjd9htUbxh+c3Sh2 tGom2ekDFsjBRAGtCp19fTJayY3V0Rmp+sG9PMr503LAm5lbD3o91X72pa4qh+RTBR Rjg6RR3CvRO+alls0AjgR+syuDZloIMC5edBJtaTkqGvMLG1V65+vC4SY6jRzfnGsX SeGccrVjM/NSQ== From: Sasha Levin To: amir73il@gmail.com, brauner@kernel.org, edvard@tuta.io Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] ovl: inherit FMODE_NONOTIFY when opening directory realfiles" failed to apply to 6.18-stable tree Date: Mon, 9 Nov 2026 20:05:28 -0500 Message-ID: <20261109200528-failed-6.18-323899b4ed23@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x 323899b4ed233d5b6e2fc160c16fbf39cf0317da # git commit -s git send-email --to '' --in-reply-to '20261109200528-failed-6.18-323899b4ed23@kernel.org' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 323899b4ed233d5b6e2fc160c16fbf39cf0317da Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Fri, 30 Oct 2026 18:07:02 +0100 Subject: [PATCH] ovl: inherit FMODE_NONOTIFY when opening directory realfiles When fanotify hands a listener an fd for a permission event on an overlay directory, ovl_dir_open_realfile() opens the real directory via dentry_open(), not backing_file_open(), so the lower open could still raise FS_OPEN_PERM and deadlock a listener that also marks the backing filesystem. Export dentry_open_nonotify() and call it from ovl_path_open_realfile() when the overlay user file must not generate events. Ordinary ovl_path_open() callers are unchanged. Reported-by: Christian Brauner (Amutable) Closes: https://lore.kernel.org/all/20261030-welpen-anbinden-nullen-b2432cee1d10@brauner/ Fixes: 130fdbc3d1f99 ("ovl: pass correct flags for opening real directory") Cc: stable@vger.kernel.org Tested-by: Edvard Conrad Link: https://lore.kernel.org/ltp/P5Iny41--F-9@tuta.io/ Signed-off-by: Amir Goldstein --- fs/open.c | 1 + fs/overlayfs/overlayfs.h | 9 ++++++++- fs/overlayfs/readdir.c | 3 ++- fs/overlayfs/util.c | 11 ++++++++++- 4 files changed, 21 insertions(+), 3 deletions(-) diff --git a/fs/open.c b/fs/open.c index e43f02ff64acb..bb484b07390ac 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1172,6 +1172,7 @@ struct file *dentry_open_nonotify(const struct path *path, int flags, } return f; } +EXPORT_SYMBOL_GPL(dentry_open_nonotify); /** * kernel_file_open - open a file for kernel internal use diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index e9389a10452e8..b5a672e8e4764 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -531,7 +531,14 @@ void ovl_dir_modified(struct dentry *dentry, bool impurity); u64 ovl_inode_version_get(struct inode *inode); bool ovl_is_whiteout(struct dentry *dentry); bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); -struct file *ovl_path_open(const struct path *path, int flags); +struct file *ovl_path_open_realfile(const struct file *user_file, + const struct path *path, int flags); + +static inline struct file *ovl_path_open(const struct path *path, int flags) +{ + return ovl_path_open_realfile(NULL, path, flags); +} + int ovl_copy_up_start(struct dentry *dentry, int flags); void ovl_copy_up_end(struct dentry *dentry); bool ovl_already_copied_up(struct dentry *dentry, int flags); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index b862309eba4d1..5d21a328fad46 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -994,7 +994,8 @@ static struct file *ovl_dir_open_realfile(const struct file *file, const struct path *realpath) { with_ovl_creds(file_inode(file)->i_sb) - return ovl_path_open(realpath, O_RDONLY | (file->f_flags & O_LARGEFILE)); + return ovl_path_open_realfile(file, realpath, + O_RDONLY | (file->f_flags & O_LARGEFILE)); } /* diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 6c3fda047f94f..788c6870d67df 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -654,7 +654,8 @@ bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path) ovl_path_check_xwhiteout_xattr(ofs, path); } -struct file *ovl_path_open(const struct path *path, int flags) +struct file *ovl_path_open_realfile(const struct file *user_file, + const struct path *path, int flags) { struct inode *inode = d_inode(path->dentry); const struct mnt_idmap *real_idmap = mnt_idmap(path->mnt); @@ -682,6 +683,14 @@ struct file *ovl_path_open(const struct path *path, int flags) if (inode_owner_or_capable(real_idmap, inode)) flags |= O_NOATIME; + /* + * Directory opens use dentry_open() here, not backing_file_open(). + * Inherit FMODE_NONOTIFY from a fanotify permission fd so a listener + * that also watches the real filesystem does not deadlock. + */ + if (user_file && FMODE_FSNOTIFY_NONE(user_file->f_mode)) + return dentry_open_nonotify(path, flags, current_cred()); + return dentry_open(path, flags, current_cred()); } -- 2.53.0