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 CFFC2DF71; Mon, 6 Jan 2025 15:55:23 +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=1736178923; cv=none; b=TdPEm1EVOsUsPvcDQuMx9t9FbqEinZE+8tUBUuE1ZGZgNQ2OJWy6oyT9+Sh9qpi7qMaUw6cIC6hGDodHSqW7MUfiPLVHCh+kZcZdXAGbNNd0DEAP2zo5HWRrbQIUAix3c6cRdE5NhxBHNmHx9X0nEkdwSk7rKdoVRSntszCLDZ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736178923; c=relaxed/simple; bh=CCzfWJHzhCbY459WQGJy20IryTDHQwWnrY86r+qfPMo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=d2PeEw30kkGwr/YiU3G5i5RbC6dyeMjggG2IgSni6h83tC32SVfJH6DWe593FP35Yku6rsl+psverfiXPxzFiG1QQ9ekLUHwvJvY52lmk97Qoemvmrj7deA3naLeW013oz6OmxsgIzUAr5g7d0HFeYiy2NR0fB/Vj1rnBq3yYD4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TCyvedRe; 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="TCyvedRe" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 17D02C4CED2; Mon, 6 Jan 2025 15:55:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1736178923; bh=CCzfWJHzhCbY459WQGJy20IryTDHQwWnrY86r+qfPMo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TCyvedReK08spgA3zae7LRuwwf7sft0azlmVRQcCTlMd0dIQ5NWgC6qUJbPpi/Ew/ WNJa2W6vSpmss27mqrIRbQ8C714CWgtzDd2r5K8fiiJKcQPN/ilSPvpWj7RdMQzAaF XLtKAwhtQ6Kiu7EPFr2iNyYsZUh5SwDDiTM+23LI= 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 5.15 106/168] tracing: Have process_string() also allow arrays Date: Mon, 6 Jan 2025 16:16:54 +0100 Message-ID: <20250106151142.463396393@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250106151138.451846855@linuxfoundation.org> References: <20250106151138.451846855@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 5.15-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 @@ -346,6 +346,18 @@ 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.