In preparation for removing the "silently change allocation size" users of ksize(), explicitly round up all q_vector allocations so that allocations can be correctly compared to ksize().
Additionally fix potential use-after-free in the case of new allocation failure: only free memory if the replacement allocation succeeds.
Cc: Jesse Brandeburg jesse.brandeburg@intel.com Cc: Tony Nguyen anthony.l.nguyen@intel.com Cc: "David S. Miller" davem@davemloft.net Cc: Eric Dumazet edumazet@google.com Cc: Jakub Kicinski kuba@kernel.org Cc: Paolo Abeni pabeni@redhat.com Cc: intel-wired-lan@lists.osuosl.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook keescook@chromium.org --- drivers/net/ethernet/intel/igb/igb_main.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 2796e81d2726..eb51e531c096 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -1195,15 +1195,16 @@ static int igb_alloc_q_vector(struct igb_adapter *adapter, return -ENOMEM;
ring_count = txr_count + rxr_count; - size = struct_size(q_vector, ring, ring_count); + size = kmalloc_size_roundup(struct_size(q_vector, ring, ring_count));
/* allocate q_vector and rings */ q_vector = adapter->q_vector[v_idx]; if (!q_vector) { q_vector = kzalloc(size, GFP_KERNEL); } else if (size > ksize(q_vector)) { - kfree_rcu(q_vector, rcu); q_vector = kzalloc(size, GFP_KERNEL); + if (q_vector) + kfree_rcu(q_vector, rcu); } else { memset(q_vector, 0, size); }