Squashfs: add sanity checks to id reading at mount time
Fsfuzzer generates corrupted filesystems which throw a warn_on in
kmalloc. One of these is due to a corrupted superblock no_ids field.
Fix this by checking that the number of bytes to be read (and allocated)
does not extend into the next filesystem structure.
Also add a couple of other sanity checks of the mount-time id table
structures.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
diff --git a/fs/squashfs/xattr.h b/fs/squashfs/xattr.h
index b634efc..9b3dd6c 100644
--- a/fs/squashfs/xattr.h
+++ b/fs/squashfs/xattr.h
@@ -31,6 +31,7 @@
u64 start, u64 *xattr_table_start, int *xattr_ids)
{
ERROR("Xattrs in filesystem, these will be ignored\n");
+ *xattr_table_start = start;
return ERR_PTR(-ENOTSUPP);
}