From f96bd8adc8adde25390965a8c1ee81b73cb62075 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 18 Oct 2022 02:25:24 -0700 Subject: [PATCH] igb: Do not free q_vector unless new one was allocated [ Upstream commit 0668716506ca66f90d395f36ccdaebc3e0e84801 ] Avoid potential use-after-free condition under memory pressure. If the kzalloc() fails, q_vector will be freed but left in the original adapter->q_vector[v_idx] array position. Cc: Jesse Brandeburg Cc: Tony Nguyen Cc: "David S. Miller" Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: intel-wired-lan@lists.osuosl.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Michael J. Ruhl Reviewed-by: Jacob Keller Tested-by: Gurucharan (A Contingent worker at Intel) Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/igb/igb_main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 37f174b41df31..10b16c292541f 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -1213,8 +1213,12 @@ static int igb_alloc_q_vector(struct igb_adapter *adapter, 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); + struct igb_q_vector *new_q_vector; + + new_q_vector = kzalloc(size, GFP_KERNEL); + if (new_q_vector) + kfree_rcu(q_vector, rcu); + q_vector = new_q_vector; } else { memset(q_vector, 0, size); }