Messages in this thread | | | Subject | Re: [PATCH] net: nvidia: forcedeth: Fix two possible concurrency use-after-free bugs | From | Yanjun Zhu <> | Date | Wed, 9 Jan 2019 09:24:48 +0800 |
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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
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