linux-kernel - [PATCH 1/2] scsi: myrb: fix -Wfortify-source

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230828-scsi_fortify-v1-1-8dde624a3b2c@google.com>
Date:   Mon, 28 Aug 2023 15:25:47 -0700
From:   Nick Desaulniers <ndesaulniers@...gle.com>
To:     Hannes Reinecke <hare@...nel.org>,
        "James E.J. Bottomley" <jejb@...ux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Nathan Chancellor <nathan@...nel.org>
Cc:     Tom Rix <trix@...hat.com>, linux-scsi@...r.kernel.org,
        linux-kernel@...r.kernel.org, llvm@...ts.linux.dev,
        Nick Desaulniers <ndesaulniers@...gle.com>
Subject: [PATCH 1/2] scsi: myrb: fix -Wfortify-source

clang-18 has improved its support for detecting operations that will
truncate values at runtime via -Wfortify-source.

Fixes the warning:
  drivers/scsi/myrb.c:1906:10: warning: 'snprintf' will always be
  truncated; specified size is 32, but format string expands to at least
  34 [-Wfortify-source]

In particular, the string literal "physical device - not rebuilding\n"
is indeed 34B by my count.

When we have a string literal that does not contain any format flags,
rather than use snprintf (sometimes with a size that's too small), let's
use sprintf.

This is pattern is cleaned up throughout the file.

Reported-by: Nathan Chancellor <nathan@...nel.org>
Closes: https://github.com/ClangBuiltLinux/linux/issues/1923
Signed-off-by: Nick Desaulniers <ndesaulniers@...gle.com>
---
 drivers/scsi/myrb.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/myrb.c b/drivers/scsi/myrb.c
index ca2e932dd9b7..c2bdff36a6f1 100644
--- a/drivers/scsi/myrb.c
+++ b/drivers/scsi/myrb.c
@@ -1767,7 +1767,7 @@ static ssize_t raid_state_show(struct device *dev,
 	int ret;
 
 	if (!sdev->hostdata)
-		return snprintf(buf, 16, "Unknown\n");
+		return sprintf(buf, "Unknown\n");
 
 	if (sdev->channel == myrb_logical_channel(sdev->host)) {
 		struct myrb_ldev_info *ldev_info = sdev->hostdata;
@@ -1890,7 +1890,7 @@ static ssize_t raid_level_show(struct device *dev,
 					ldev_info->state);
 		return snprintf(buf, 32, "%s\n", name);
 	}
-	return snprintf(buf, 32, "Physical Drive\n");
+	return sprintf(buf, "Physical Drive\n");
 }
 static DEVICE_ATTR_RO(raid_level);
 
@@ -1903,13 +1903,13 @@ static ssize_t rebuild_show(struct device *dev,
 	unsigned char status;
 
 	if (sdev->channel < myrb_logical_channel(sdev->host))
-		return snprintf(buf, 32, "physical device - not rebuilding\n");
+		return sprintf(buf, "physical device - not rebuilding\n");
 
 	status = myrb_get_rbld_progress(cb, &rbld_buf);
 
 	if (rbld_buf.ldev_num != sdev->id ||
 	    status != MYRB_STATUS_SUCCESS)
-		return snprintf(buf, 32, "not rebuilding\n");
+		return sprintf(buf, "not rebuilding\n");
 
 	return snprintf(buf, 32, "rebuilding block %u of %u\n",
 			rbld_buf.ldev_size - rbld_buf.blocks_left,

-- 
2.42.0.rc2.253.gd59a3bf2b4-goog