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

Message ID 20210923014945.6229-2-chaitanyak@nvidia.com (mailing list archive)
State New, archived
Headers show
Series loop: small clenaup | expand

Commit Message

Chaitanya Kulkarni Sept. 23, 2021, 1:49 a.m. UTC 
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 <himanshu.madhani@oracle.com>
---
 drivers/block/loop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
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Patch

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)