Thread (9 messages) 9 messages, 1 author, 2021-09-23

[PATCH V2 1/8] loop: use sysfs_emit() in the sysfs offset show

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STALE1843d REVIEWED: 1 (0M)

From: Chaitanya Kulkarni <hidden>
Date: 2021-09-23 01:50:07
Subsystem: block layer, the rest · Maintainers: Jens Axboe, Linus Torvalds

Revision v2 of 2 in this series; 1 review trailer.

Revisions (2)
  1. v1 [diff vs current]
  2. v2 current
From: Chaitanya Kulkarni <kch@nvidia.com>

sprintf does not know the PAGE_SIZE maximum of the temporary buffer
used for outputting sysfs content and it's possible to overrun the
PAGE_SIZE buffer length.

Use a generic sysfs_emit function that knows the size of the
temporary buffer and ensures that no overrun is done for offset
attribute.

Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Himanshu Madhani <redacted>
---
 drivers/block/loop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 7bf4686af774..e37444977ae6 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -856,7 +856,7 @@ static ssize_t loop_attr_backing_file_show(struct loop_device *lo, char *buf)
 
 static ssize_t loop_attr_offset_show(struct loop_device *lo, char *buf)
 {
-	return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_offset);
+	return sysfs_emit(buf, "%llu\n", (unsigned long long)lo->lo_offset);
 }
 
 static ssize_t loop_attr_sizelimit_show(struct loop_device *lo, char *buf)
-- 
2.29.0
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