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=1794063824; b=qUTBv/9AnbPrz10A3mREsmkQLgA8bM4v9u0B4/NZ+HtdcV5grKTzHxn1XAb88ttC1X+A n8BXeO1Kv9sWXr3xuN7vsNOq3fJGDS4tUO7vhBGIYrg77weOTuNqo84h6GSt6Gn+A4Q0q XHQyibQdHF2q/ADqBFwitj8VXFRsmEg/G77kbhJw2bmXEpxtBiJcYeZs8Ke0wMuvYv5SR 2QRDeofs7VtcjiScGMom7xfKSAq/LDkVMxr4gh4+mHgBrI7APzGZoR7STm3Q4pIlN6G4C 1XMgkcb9RckffzxN4ODB07SvWrF/nZcERp6q3FjbqLQeAjadAaJwKmTAGyVkoStlEng== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063824; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=n2ssaBCVqMDy+OHs+X/koEcu44YGZSgaGV+bbUozERQ=; b=CV41QXYFWQov4k4IDKAiFtL4LyETSo6qxglXoFs4n+80XPq3gWa2dy9ycEWtEcVlu3TE I76oVN3teJEp6MvjkOY9HHLvgKY5oOnT3x8jUQ7UWH37j0cFirYuqEKFmOOBPdCacfDDk SOOnZ00tGjwSJlVhfGt2G1KDH2FUbWouHuj8GPGmhylq8gRQqRyLdJ5AqIllNsAjT7uW6 7hiIfEjmPaACPOg0ClHQsNb9vpIJPRKNd1w7SsYvTpjBwR6cXttbAq7T/z5hP8dq2SRnQ H1qNggUd/klzoXHYKZbldC4xEE6W9i1gdk5fjRT2UBWImBzspeO93zFmw/Nj18iFUiA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=AWtYfMpt; 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 9ACC2606A326; Sat, 7 Nov 2026 15:03:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=AWtYfMpt Received: by smtp.kernel.org (Postfix) with ESMTPSA id 496121F0089F; Sat, 7 Nov 2026 15:03:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063824; bh=n2ssaBCVqMDy+OHs+X/koEcu44YGZSgaGV+bbUozERQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AWtYfMptjvqxHBcRI7BYSiZAa4dbrU8q/6vNSXJkjlID9S/f/OJslK63bGCxUizPU IDB3lyx3QqO/GvRQ0R0Y7ahyu4bOrJwJuYn+V7/4L9hHSsjeJRYJr5sSZgNDuU7ZDh Gsfi6uplSvebvSJKX7IO8DHnLRHXdRD+xdSFj3+0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Daehyeon Ko <4ncienth@gmail.com>, "Christian Brauner (Amutable)" , Sasha Levin Subject: [PATCH 7.3 0039/1257] ipc/mqueue: release notification resources during inode eviction Date: Sat, 7 Nov 2026 08:38:55 -0500 Message-ID: <20261107134940.487451969@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134939.434104957@linuxfoundation.org> References: <20261107134939.434104957@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daehyeon Ko <4ncienth@gmail.com> [ Upstream commit eb85469f0dd69ca145d63117450e14c31f67f698 ] mqueue_flush_file() removes an mq_notify() registration only when the closing task belongs to the thread group stored in notify_owner. A task in a separate thread group created with CLONE_FILES can register SIGEV_THREAD notification and exit without closing the shared file table. If another thread group then unlinks and last-closes the queue, ->flush() skips the registration and inode eviction loses the only pointers to its resources. The orphaned registration permanently retains the notification skb, its netlink socket, a pid reference and a user namespace reference. An unprivileged process can repeat the sequence with new queues and sockets. No inode users remain during eviction. Remove any stale registration there after dropping info->lock, since netlink_sendskb() may release the final socket reference. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Link: https://patch.msgid.link/20260824042359.925145-1-4ncienth@gmail.com Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin --- ipc/mqueue.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/ipc/mqueue.c b/ipc/mqueue.c index d1dd36a651b0d..d1a1965c98118 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -528,6 +528,13 @@ static void mqueue_evict_inode(struct inode *inode) list_add_tail(&msg->m_list, &tmp_msg); kfree(info->node_cache); spin_unlock(&info->lock); + /* + * A shared file table can let the notification owner exit without + * running ->flush(). No users of the inode remain during eviction, so + * tear down any stale notification after dropping info->lock because + * netlink_sendskb() may release the final socket reference. + */ + remove_notification(info); list_for_each_entry_safe(msg, nmsg, &tmp_msg, m_list) { list_del(&msg->m_list); -- 2.53.0