From: Fedor Pchelkin pchelkin@ispras.ru
[ Upstream commit 0c0cf3db83f8c7c9bb141c2771a34043bcf952ef ]
Inside macsec_add_dev() we free percpu macsec->secy.tx_sc.stats and macsec->stats on some of the memory allocation failure paths. However, the net_device is already registered to that moment: in macsec_newlink(), just before calling macsec_add_dev(). This means that during unregister process its priv_destructor - macsec_free_netdev() - will be called and will free the stats again.
Remove freeing percpu stats inside macsec_add_dev() because macsec_free_netdev() will correctly free the already allocated ones. The pointers to unallocated stats stay NULL, and free_percpu() treats that correctly.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Fixes: 0a28bfd4971f ("net/macsec: Add MACsec skb_metadata_dst Tx Data path support") Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver") Signed-off-by: Fedor Pchelkin pchelkin@ispras.ru Reviewed-by: Sabrina Dubroca sd@queasysnail.net Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/macsec.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index 25616247d7a56..e040c191659b9 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -3987,17 +3987,15 @@ static int macsec_add_dev(struct net_device *dev, sci_t sci, u8 icv_len) return -ENOMEM;
secy->tx_sc.stats = netdev_alloc_pcpu_stats(struct pcpu_tx_sc_stats); - if (!secy->tx_sc.stats) { - free_percpu(macsec->stats); + if (!secy->tx_sc.stats) return -ENOMEM; - }
secy->tx_sc.md_dst = metadata_dst_alloc(0, METADATA_MACSEC, GFP_KERNEL); - if (!secy->tx_sc.md_dst) { - free_percpu(secy->tx_sc.stats); - free_percpu(macsec->stats); + if (!secy->tx_sc.md_dst) + /* macsec and secy percpu stats will be freed when unregistering + * net_device in macsec_free_netdev() + */ return -ENOMEM; - }
if (sci == MACSEC_UNDEF_SCI) sci = dev_to_sci(dev, MACSEC_PORT_ES);