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 <v...@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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/