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@xxxxxxxxxx> Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx> --- 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 bdea448d2419..f6ed265d34e7 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -680,7 +680,7 @@ 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