| Message ID | 20210524102320.10122-1-lyl2019@mail.ustc.edu.cn |
|---|---|
| State | New |
| Headers | show |
| Series | scsi/bnx2fc/bnx2fx_fcore: Fix a double free in bnx2fc_rcv | expand |
diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c index 8863a74e6c57..89c277cb93b2 100644 --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c @@ -445,11 +445,10 @@ static int bnx2fc_rcv(struct sk_buff *skb, struct net_device *dev, } tmp_skb = skb_share_check(skb, GFP_ATOMIC); + skb = tmp_skb; if (!tmp_skb) goto err; - skb = tmp_skb; - if (unlikely(eth_hdr(skb)->h_proto != htons(ETH_P_FCOE))) { printk(KERN_ERR PFX "bnx2fc_rcv: Wrong FC type frame\n"); goto err;
In bnx2fc_rcv, it calls skb_share_check(skb,GFP_ATOMIC) to clone the skb. But if skb_clone() failed, skb_share_check() will free the skb in the first time and return NULL. Then skb_share_check() returns NULL and goto err. Unfortunately, the same skb is freed in the second time in the err. As kfree_skb() free a null pointer is a safe operation, my patch put "skb = tmp_skb;" ahead of the "if(!tmp_skb) goto err;". So that if skb_share_check() failed, skb will be a null pointer. Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn> --- drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)