RDMA/uverbs: Don't fail in creation of multiple flows

The conversion from offsetof() calculations to sizeof()
wrongly behaved for missed exact size and in scenario with
more than one flow.

In such scenario we got "create flow failed, flow 10: 8 bytes
left from uverb cmd" error, which is wrong because the size of
kern_spec is exactly 8 bytes, and we were not supposed to fail.

Cc: <stable@vger.kernel.org> # 3.12
Fixes: 4fae7f1704 ("RDMA/uverbs: Fix slab-out-of-bounds in ib_uverbs_ex_create_flow")
Reported-by: Ran Rozenstein <ranro@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This commit is contained in:
Leon Romanovsky 2018-07-01 15:31:54 +03:00 committed by Jason Gunthorpe
parent b697d7d8c7
commit fe48aecb4d

View file

@ -3586,7 +3586,7 @@ int ib_uverbs_ex_create_flow(struct ib_uverbs_file *file,
kern_spec = kern_flow_attr->flow_specs;
ib_spec = flow_attr + 1;
for (i = 0; i < flow_attr->num_of_specs &&
cmd.flow_attr.size > sizeof(*kern_spec) &&
cmd.flow_attr.size >= sizeof(*kern_spec) &&
cmd.flow_attr.size >= kern_spec->size;
i++) {
err = kern_spec_to_ib_spec(