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 in
loop_attr_[offset|sizelimit|autoclear|partscan|dio]_show() callbacks.
Signed-off-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
---
drivers/block/loop.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index bdea448d2419..a55e5eda1d17 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -680,33 +680,33 @@ 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)
{
- return sprintf(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit);
+ return sysfs_emit(buf, "%llu\n", (unsigned long long)lo->lo_sizelimit);
}
static ssize_t loop_attr_autoclear_show(struct loop_device *lo, char *buf)
{
int autoclear = (lo->lo_flags & LO_FLAGS_AUTOCLEAR);
- return sprintf(buf, "%s\n", autoclear ? "1" : "0");
+ return sysfs_emit(buf, "%s\n", autoclear ? "1" : "0");
}
static ssize_t loop_attr_partscan_show(struct loop_device *lo, char *buf)
{
int partscan = (lo->lo_flags & LO_FLAGS_PARTSCAN);
- return sprintf(buf, "%s\n", partscan ? "1" : "0");
+ return sysfs_emit(buf, "%s\n", partscan ? "1" : "0");
}
static ssize_t loop_attr_dio_show(struct loop_device *lo, char *buf)
{
int dio = (lo->lo_flags & LO_FLAGS_DIRECT_IO);
- return sprintf(buf, "%s\n", dio ? "1" : "0");
+ return sysfs_emit(buf, "%s\n", dio ? "1" : "0");
}
LOOP_ATTR_RO(backing_file);
--
2.29.0
