Messages in this thread Patch in this message | | | From | Vladimir Zapolskiy <> | Subject | [PATCH] fs: sysfs: don't pass count == 0 to bin file readers | Date | Fri, 22 May 2015 00:21:16 +0300 |
| |
If count == 0 bytes are requested by a reader, sysfs_kf_bin_read() deliberately returns 0 without passing a potentially harmful value to some externally defined underlying battr->read() function.
However in case of (pos == size && count) the next clause always sets count to 0 and this value is handed over to battr->read().
The change intends to make obsolete (and remove later) a redundant sanity check in battr->read(), if it is present, or add more protection to struct bin_attribute users, who does not care about input arguments.
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com> --- fs/sysfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 7c2867b..6c95628 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -90,7 +90,7 @@ static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf, return 0; if (size) { - if (pos > size) + if (pos >= size) return 0; if (pos + count > size) count = size - pos; -- 1.7.10.4
| |