From nobody Sun Feb 8 21:26:27 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7E58C7EE29 for ; Mon, 22 May 2023 20:36:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234839AbjEVUgd (ORCPT ); Mon, 22 May 2023 16:36:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234895AbjEVUgU (ORCPT ); Mon, 22 May 2023 16:36:20 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AAD7E19D; Mon, 22 May 2023 13:35:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 30AFD62BD6; Mon, 22 May 2023 20:35:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7AD92C433D2; Mon, 22 May 2023 20:35:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684787752; bh=0nQ8xIPSPhBIr1gc3+npYhNke4IXHy+5EM39FqGHhHM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RvIIl7JwcJq1f1lT50bQTaPuLv0NZy78hJqb4UTvWapPNbd41FW80wvaW4pH0aAOo 4TFqg8491i9Zl3rQRFtYXMLVrUEjAIN2Sus2yH0U8HOELjOAhTmZZlj6/RVSV3KFvt Xe9iqVfgcL67vJ4LphGTNfl2Ao1Ub0EQ7bS13b2S6nILe6dKwQjN4s3A5ifjdgD6B8 HKSBErLqGZ2KGI5RO4zGnfoSCGGwg236gdTcm9UFy3mIkKjxjyKFjwyOA5VTnN1Ir6 STLK7od7jNeP4m7FYg/VWUGu+uTiQw4V/Ub1n/8uiGlC7+KimKstqJvqYoDpmxE5EM cl8yPMWAoz3Ag== From: Jiri Olsa To: stable@vger.kernel.org Cc: Christoph Hellwig , John Fastabend , linux-mm@kvack.org, bpf@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Masami Hiramatsu , Tsahee Zidenberg , Andrii Nakryiko , Daniel Borkmann , Thomas Gleixner , =?UTF-8?q?Mah=C3=A9=20Tardy?= , linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH stable 5.4 8/8] bpf: bpf_probe_read_kernel_str() has to return amount of data read on success Date: Mon, 22 May 2023 22:33:52 +0200 Message-Id: <20230522203352.738576-9-jolsa@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230522203352.738576-1-jolsa@kernel.org> References: <20230522203352.738576-1-jolsa@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Andrii Nakryiko commit 02553b91da5deb63c8562b47529b09b734659af0 upstream. During recent refactorings, bpf_probe_read_kernel_str() started returning 0= on success, instead of amount of data successfully read. This majorly breaks applications relying on bpf_probe_read_kernel_str() and bpf_probe_read_str() and their results. Fix this by returning actual number of bytes read. Fixes: 8d92db5c04d1 ("bpf: rework the compat kernel probe handling") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Reviewed-by: Christoph Hellwig Acked-by: John Fastabend Link: https://lore.kernel.org/bpf/20200616050432.1902042-1-andriin@fb.com --- kernel/trace/bpf_trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index a46256f99229..c4c825dcdef8 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -198,7 +198,7 @@ bpf_probe_read_kernel_str_common(void *dst, u32 size, c= onst void *unsafe_ptr) if (unlikely(ret < 0)) goto fail; =20 - return 0; + return ret; fail: memset(dst, 0, size); return ret; --=20 2.40.1