[PATCH 1/2] scsi: myrb: Fix a potential string truncation in rebuild_show()

From: Christophe JAILLET
Date: Tue Dec 12 2023 - 15:09:47 EST


"physical device - not rebuilding\n" is 34 bytes long. When written in
'buf' with a limit of 32 bytes, it is truncated.

When building with W=1, it leads to:
drivers/scsi/myrb.c: In function ‘rebuild_show’:
drivers/scsi/myrb.c:1906:24: error: ‘physical device - not rebuil...’ directive output truncated writing 33 bytes into a region of size 32 [-Werror=format-truncation=]
1906 | return snprintf(buf, 32, "physical device - not rebuilding\n");
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/scsi/myrb.c:1906:24: note: ‘snprintf’ output 34 bytes into a destination of size 32

Change the allowed size to 64 to fix the issue.

Fixes: 081ff398c56c ("scsi: myrb: Add Mylex RAID controller (block interface)")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
drivers/scsi/myrb.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/myrb.c b/drivers/scsi/myrb.c
index ca2e932dd9b7..ca2380d2d6d3 100644
--- a/drivers/scsi/myrb.c
+++ b/drivers/scsi/myrb.c
@@ -1903,15 +1903,15 @@ 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 snprintf(buf, 64, "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 snprintf(buf, 64, "not rebuilding\n");

- return snprintf(buf, 32, "rebuilding block %u of %u\n",
+ return snprintf(buf, 64, "rebuilding block %u of %u\n",
rbld_buf.ldev_size - rbld_buf.blocks_left,
rbld_buf.ldev_size);
}
--
2.34.1