From: Kees Cook <keescook@xxxxxxxxxxxx> [ 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 <jesse.brandeburg@xxxxxxxxx> Cc: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> Cc: Paolo Abeni <pabeni@xxxxxxxxxx> Cc: intel-wired-lan@xxxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Reviewed-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx> Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx> Tested-by: Gurucharan <gurucharanx.g@xxxxxxxxx> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 70667b46858a..b246ff8b7c20 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -1204,8 +1204,12 @@ 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); } -- 2.35.1