IB/uverbs: Fix reading of 32 bit flags

This is missing a zeroing of the high bits of flags, and is also not
correct for big endian machines. Properly zero extend the 32 bit flags
into the 64 bit stack variable.

Reported-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Fixes: bccd06223f21 ("IB/uverbs: Add UVERBS_ATTR_FLAGS_IN to the specs language")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>

diff --git a/drivers/infiniband/core/uverbs_ioctl.c b/drivers/infiniband/core/uverbs_ioctl.c
index f0655a8..23ff698 100644 (file)
--- a/drivers/infiniband/core/uverbs_ioctl.c
+++ b/drivers/infiniband/core/uverbs_ioctl.c
@@ -535,7 +535,7 @@ int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
        if (attr->ptr_attr.len == 8)
                flags = attr->ptr_attr.data;
        else if (attr->ptr_attr.len == 4)
-               memcpy(&flags, &attr->ptr_attr.data, 4);
+               flags = *(u32 *)&attr->ptr_attr.data;
        else
                return -EINVAL;