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 32C243FB35; Tue, 16 Jan 2024 19:45:22 +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=1705434323; cv=none; b=jzfNyQ1R+UxgQwZW2IFcJGP96uBH1ggHtbs4gjcH5b5E4ZjQ9mUl6YjlddVVbIIro7cOobr9qyhoveCpD7zEBQgCBAl4S1g8JxjuITKyCUQ1Yrg/9Kp+ofR/Cr+24Rgjnp/h6bZ9q+4y3mroPJxpqOXF3w+9ChyL49QZP1FlDnI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705434323; c=relaxed/simple; bh=4vf9MSNWAubfBAh0ArsuBB9cwHDCLIIqku+4MwBPn1k=; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version:X-stable: X-Patchwork-Hint:X-stable-base:Content-Transfer-Encoding; b=UjiWR4evignqlp/SGH5phPuIb6h/tkwJYRJtWJJ3AKDnStowC8gwynH9HOrjXsIK/FjXiTYR3XUC9z6Sl7wL4JtVvXC/ykfnIwaDTJmGIbONqCtFaPuRSrMKm1kzt3UZMecX53FM++DfrVw4G8zQWacfBtNb8mMWF8EULbYTMWs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mR26B9A/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mR26B9A/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BD56C433F1; Tue, 16 Jan 2024 19:45:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705434322; bh=4vf9MSNWAubfBAh0ArsuBB9cwHDCLIIqku+4MwBPn1k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mR26B9A/6/4UmBKgrWOJgSs+iNmTOLEtUSghFcwasb6wKhzOoC74pSoGrkntm8fTc 3lCDO1LCz5BXWrhyh28ssJyV+8FpCbc5JbtOdaZZHo57SKKV+hkccYfQdmzVaoW8ss ld2BWH3QeD4C0v/co/W9WemNJT/qKvdE9U00RrdfoIiFnJafUFaacBgvJdKk5nrGHQ cxBOIBUo6g5lChmn9LJU0Vg/0bS2hoaZD8mEnx0AKhCsAX4DrKDrf1CdPeQDoWbNyc TB+e3BHTfUcvcLCfTPhLUy4mjOW5Rm2P+I8tePCvymJh5BjnVzny/cTRM1s/mAzjig SqaHV6jfdnGqg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kees Cook , kernel test robot , "Md . Haris Iqbal" , Jack Wang , Jens Axboe , linux-block@vger.kernel.org, Guoqing Jiang , Sasha Levin Subject: [PATCH AUTOSEL 6.7 063/108] block/rnbd-srv: Check for unlikely string overflow Date: Tue, 16 Jan 2024 14:39:29 -0500 Message-ID: <20240116194225.250921-63-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240116194225.250921-1-sashal@kernel.org> References: <20240116194225.250921-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.7 Content-Transfer-Encoding: 8bit From: Kees Cook [ Upstream commit 9e4bf6a08d1e127bcc4bd72557f2dfafc6bc7f41 ] Since "dev_search_path" can technically be as large as PATH_MAX, there was a risk of truncation when copying it and a second string into "full_path" since it was also PATH_MAX sized. The W=1 builds were reporting this warning: drivers/block/rnbd/rnbd-srv.c: In function 'process_msg_open.isra': drivers/block/rnbd/rnbd-srv.c:616:51: warning: '%s' directive output may be truncated writing up to 254 bytes into a region of size between 0 and 4095 [-Wformat-truncation=] 616 | snprintf(full_path, PATH_MAX, "%s/%s", | ^~ In function 'rnbd_srv_get_full_path', inlined from 'process_msg_open.isra' at drivers/block/rnbd/rnbd-srv.c:721:14: drivers/block/rnbd/rnbd-srv.c:616:17: note: 'snprintf' output between 2 and 4351 bytes into a destination of size 4096 616 | snprintf(full_path, PATH_MAX, "%s/%s", | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 617 | dev_search_path, dev_name); | ~~~~~~~~~~~~~~~~~~~~~~~~~~ To fix this, unconditionally check for truncation (as was already done for the case where "%SESSNAME%" was present). Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202312100355.lHoJPgKy-lkp@intel.com/ Cc: Md. Haris Iqbal Cc: Jack Wang Cc: Jens Axboe Cc: Signed-off-by: Kees Cook Acked-by: Guoqing Jiang Acked-by: Jack Wang Link: https://lore.kernel.org/r/20231212214738.work.169-kees@kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/rnbd/rnbd-srv.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/block/rnbd/rnbd-srv.c b/drivers/block/rnbd/rnbd-srv.c index 65de51f3dfd9..ab78eab97d98 100644 --- a/drivers/block/rnbd/rnbd-srv.c +++ b/drivers/block/rnbd/rnbd-srv.c @@ -585,6 +585,7 @@ static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess, { char *full_path; char *a, *b; + int len; full_path = kmalloc(PATH_MAX, GFP_KERNEL); if (!full_path) @@ -596,19 +597,19 @@ static char *rnbd_srv_get_full_path(struct rnbd_srv_session *srv_sess, */ a = strnstr(dev_search_path, "%SESSNAME%", sizeof(dev_search_path)); if (a) { - int len = a - dev_search_path; + len = a - dev_search_path; len = snprintf(full_path, PATH_MAX, "%.*s/%s/%s", len, dev_search_path, srv_sess->sessname, dev_name); - if (len >= PATH_MAX) { - pr_err("Too long path: %s, %s, %s\n", - dev_search_path, srv_sess->sessname, dev_name); - kfree(full_path); - return ERR_PTR(-EINVAL); - } } else { - snprintf(full_path, PATH_MAX, "%s/%s", - dev_search_path, dev_name); + len = snprintf(full_path, PATH_MAX, "%s/%s", + dev_search_path, dev_name); + } + if (len >= PATH_MAX) { + pr_err("Too long path: %s, %s, %s\n", + dev_search_path, srv_sess->sessname, dev_name); + kfree(full_path); + return ERR_PTR(-EINVAL); } /* eliminitate duplicated slashes */ -- 2.43.0