fs/squashfs: parameter check sqfs_read_metablock()

We should check if the incoming parameter file_mapping is not NULL instead
of checking after adding an offset.

Reported-by: Coverity CID 307210
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

diff --git a/fs/squashfs/sqfs_inode.c b/fs/squashfs/sqfs_inode.c
index 1368f30..14d70cf 100644 (file)
--- a/fs/squashfs/sqfs_inode.c
+++ b/fs/squashfs/sqfs_inode.c
@@ -141,9 +141,9 @@ int sqfs_read_metablock(unsigned char *file_mapping, int offset,
        const unsigned char *data;
        u16 header;
 
-       data = file_mapping + offset;
-       if (!data)
+       if (!file_mapping)
                return -EFAULT;
+       data = file_mapping + offset;
 
        header = get_unaligned((u16 *)data);
        if (!header)