lseek: ensure errno is set on failure and return -1

All error paths before calling the driver's lseek callback return -1 and
set errno. Do the same if the callback returns an error.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 7 insertions, 1 deletions

diff --git a/fs/fs.c b/fs/fs.c
index 2b4659cfbb..e7b6965914 100644
--- a/fs/fs.c
+++ b/fs/fs.c
@@ -926,7 +926,13 @@ loff_t lseek(int fildes, loff_t offset, int whence)
 		goto out;
 	}
 
-	return fsdrv->lseek(&f->fsdev->dev, f, pos);
+	pos = fsdrv->lseek(&f->fsdev->dev, f, pos);
+	if (pos < 0) {
+		errno = -pos;
+		return -1;
+	}
+
+	return pos;
 
 out:
 	if (ret)