On 2019/1/8 20:57, Jia-Ju Bai wrote:
On 2019/1/8 20:54, Zhu Yanjun wrote:
在 2019/1/8 20:45, Jia-Ju Bai 写道:
In drivers/net/ethernet/nvidia/forcedeth.c, the functions
nv_start_xmit() and nv_start_xmit_optimized() can be concurrently
executed with nv_poll_controller().
nv_start_xmit
line 2321: prev_tx_ctx->skb = skb;
nv_start_xmit_optimized
line 2479: prev_tx_ctx->skb = skb;
nv_poll_controller
nv_do_nic_poll
line 4134: spin_lock(&np->lock);
nv_drain_rxtx
nv_drain_tx
nv_release_txskb
line 2004: dev_kfree_skb_any(tx_skb->skb);
Thus, two possible concurrency use-after-free bugs may occur.
To fix these possible bugs,
Does this really occur? Can you reproduce this ?
This bug is not found by the real execution.
It is found by a static tool written by myself, and then I check it by
manual code review.
Before "line 2004: dev_kfree_skb_any(tx_skb->skb); ",
"
nv_disable_irq(dev);
nv_napi_disable(dev);
netif_tx_lock_bh(dev);
netif_addr_lock(dev);
spin_lock(&np->lock);
/* stop engines */
nv_stop_rxtx(dev); <---this stop rxtx
nv_txrx_reset(dev);
"
In this case, does nv_start_xmit or nv_start_xmit_optimized still work well?
Zhu Yanjun
Best wishes,
Jia-Ju Bai
