get_component_size(): Check read() return value for error before using it

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 1 insertions, 1 deletions

diff --git a/sysfs.c b/sysfs.c
index 6c17c5e4..d923f7fb 100644
--- a/sysfs.c
+++ b/sysfs.c
@@ -379,7 +379,7 @@ unsigned long long get_component_size(int fd)
 		return 0;
 	n = read(fd, fname, sizeof(fname));
 	close(fd);
-	if (n == sizeof(fname))
+	if (n < 0 || n == sizeof(fname))
 		return 0;
 	fname[n] = 0;
 	return strtoull(fname, NULL, 10) * 2;