From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 5E480481AF; Mon, 6 Jan 2025 15:28:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736177295; cv=none; b=ou25P8KGrBgx/sLCT8gHW82kaLF9adIwJ7qyahzbzA389Fd49dUiEGaFCV+fHmLEp3KnViMnrh/GamAxYXuWYmYeOqkye7LWkGqA/FACKdc+cKEc8LXtaWCdN3U6IEbs9U5sKOozxxwvrOKhiwBVbC6bL8txeMemaRay6TACGzM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736177295; c=relaxed/simple; bh=7lH+6zf4kQDsYiizOgSmjbdJIonvN5TkV5P9y5aEPkE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jrCWOd9Yx6k+XI4vtrCYPds4RIuvAljtvupqpmMQNxlUL7scIpHsEPtYqnMUquYkAPZNtstTfTE3PQn+9ZiR/OdnrCHAWNRD78zAGiJHbs3bBvT9aZVR759j7wwlJshe++BX1TSOMWO+ZP8VrnpmR4lWyvLgwN83WC+WoIef6Ew= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cyH/JskC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="cyH/JskC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93E4AC4CED2; Mon, 6 Jan 2025 15:28:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1736177295; bh=7lH+6zf4kQDsYiizOgSmjbdJIonvN5TkV5P9y5aEPkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cyH/JskCFzci2xt/WTmauMJu+oRAJY+kmS/yUjj2cPZxfy470ngoqjzGHn3GDp+P+ 5ezIWm+9NJpTppKMOIgtXgATCWtPJEbIcUWq4gK+qyKRaeaawMEIn1f9yaipyYtBg4 GQeE1NZntEQGqeOjSFXqwlNqgZgfcwMbnLAveaD4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Masami Hiramatsu , Mathieu Desnoyers , Genes Lists , Gene C , "Steven Rostedt (Google)" Subject: [PATCH 6.6 116/222] tracing: Have process_string() also allow arrays Date: Mon, 6 Jan 2025 16:15:20 +0100 Message-ID: <20250106151154.987834299@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250106151150.585603565@linuxfoundation.org> References: <20250106151150.585603565@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt commit afc6717628f959941d7b33728570568b4af1c4b8 upstream. In order to catch a common bug where a TRACE_EVENT() TP_fast_assign() assigns an address of an allocated string to the ring buffer and then references it in TP_printk(), which can be executed hours later when the string is free, the function test_event_printk() runs on all events as they are registered to make sure there's no unwanted dereferencing. It calls process_string() to handle cases in TP_printk() format that has "%s". It returns whether or not the string is safe. But it can have some false positives. For instance, xe_bo_move() has: TP_printk("move_lacks_source:%s, migrate object %p [size %zu] from %s to %s device_id:%s", __entry->move_lacks_source ? "yes" : "no", __entry->bo, __entry->size, xe_mem_type_to_name[__entry->old_placement], xe_mem_type_to_name[__entry->new_placement], __get_str(device_id)) Where the "%s" references into xe_mem_type_to_name[]. This is an array of pointers that should be safe for the event to access. Instead of flagging this as a bad reference, if a reference points to an array, where the record field is the index, consider it safe. Link: https://lore.kernel.org/all/9dee19b6185d325d0e6fa5f7cbba81d007d99166.camel@sapience.com/ Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20241231000646.324fb5f7@gandalf.local.home Fixes: 65a25d9f7ac02 ("tracing: Add "%s" check in test_event_printk()") Reported-by: Genes Lists Tested-by: Gene C Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -361,6 +361,18 @@ static bool process_string(const char *f } while (s < e); /* + * Check for arrays. If the argument has: foo[REC->val] + * then it is very likely that foo is an array of strings + * that are safe to use. + */ + r = strstr(s, "["); + if (r && r < e) { + r = strstr(r, "REC->"); + if (r && r < e) + return true; + } + + /* * If there's any strings in the argument consider this arg OK as it * could be: REC->field ? "foo" : "bar" and we don't want to get into * verifying that logic here.