From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8CFFF4B04B4; Sun, 9 Aug 2026 02:32:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786242736; cv=none; b=f1/UgcDbVLwfRwy3v562Q+sd2cz6rLDVPwoP/XUpv9pwS8IkyeKY/RZNz3LNg/byBjOFj1Z05hFi8QdY5q9jLDqG8LZR512Q5Nfli8ngR+xX5CWGuINSqgk9lqo4Pmxn87bd07+kRYqTg/jVLAUhRvuGZvhOGDPGusB1NRkcno8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786242736; c=relaxed/simple; bh=naau0ZOdwTgmpgP6cMAH3GyyjG/taDOzyWzYW6EhqFA=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=f8eBUmWVXA2iyywyAOAux+UclWzGdDzUTSQx+CVlrGpq521mK8rjjWtoli8ADMFpQMEKWrs7vCje1ISkuv/ZNklHOwLgO3nIYdHtO+tLBkwM6jOaS+XTBPvJRMLuzw1EEjYfmbvncCMho9GHguGK2zO0W/xjeNC0NRk1v7nnH8M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dwzlAUl4; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dwzlAUl4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2DCB01F000E9; Sun, 9 Aug 2026 02:32:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786242735; bh=uqDm7PtLMIMrxxQDn6i+3zQIKR04zfptQqpulm1NEP0=; h=Date:From:To:Cc:Subject:References; b=dwzlAUl4R3s2t7Dg/kJFoXTKnfLrrsnXjxiLNKWifFeb8UzkZNsd2o8ZymOZ5XZPn cwuOru7O0vBKjWzZBuzcLFHV66TO96aGkUrYrIWZkAMGTlYzk6nSs62FxJvGPgr/S5 fBXBRru5rjLDnXJ7IKSOn+x+RJOrJrulmUFpZygNS5xkuJQ/wRvmdL1I2LhNjwxspt nRIKjsYifUc/Pm8cQ35/YByC4dFUgh/EBJ61nuKX8on2Dp4hiQroFPnkUQQ/XLmetf LjnEu+yNnS7HREFExArkZV4VWxkJvZYn/cwbvFr6P6ZJzJzq+yNzi4wUYZ1qqD1lqT mYSgdtzI0qOvg== Received: from rostedt by gandalf with local (Exim 4.99.4) (envelope-from ) id 1wstKn-00000001N2l-28sU; Sat, 08 Aug 2026 22:32:21 -0400 Message-ID: <20260809023221.366243140@kernel.org> User-Agent: quilt/0.69 Date: Sat, 08 Aug 2026 22:31:45 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org, Shuangpeng Bai Subject: [for-linus][PATCH 01/12] eventfs: Fix use-after-free in eventfs_remove_rec() References: <20260809023144.852271250@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Shuangpeng Bai eventfs_remove_rec() recursively removes the child at the current loop position. After the recursive call returns, list_for_each_entry() advances by reading list.next from the removed child. If free_ei() drops the final reference, release_ei() reuses the list/rcu union to queue an SRCU callback. The child may be freed before that read. The eventfs_mutex serializes list updates, but it does not keep the removed child alive or prevent the SRCU callback from running. Use list_for_each_entry_safe() to save the next sibling before recursively removing the current child. Cc: stable@vger.kernel.org Fixes: 43aa6f97c2d0 ("eventfs: Get rid of dentry pointers without refcounts") Link: https://patch.msgid.link/20260806022719.375354-1-shuangpeng.kernel@gmail.com Signed-off-by: Shuangpeng Bai Acked-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt --- fs/tracefs/event_inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 39c7a34531e8..93bc4f83b73e 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -822,7 +822,7 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry */ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) { - struct eventfs_inode *ei_child; + struct eventfs_inode *ei_child, *tmp; /* * Check recursion depth. It should never be greater than 3: @@ -835,7 +835,7 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) return; /* search for nested folders or files */ - list_for_each_entry(ei_child, &ei->children, list) + list_for_each_entry_safe(ei_child, tmp, &ei->children, list) eventfs_remove_rec(ei_child, level + 1); list_del_rcu(&ei->list); -- 2.53.0