tg3: avoid double-freeing of rx data memory (85aec73d) · Commits · 戴 / test

If build_skb fails the memory associated with the ring buffer is freed but the ri->data member is not zeroed in this case. This causes a double-free of this memory in tg3_free_rings->... path. The patch moves this block after setting ri->data to NULL. It would be nice to fix this bug also in stable >= v3.4 trees. Cc: Nithin Nayak Sujir <nsujir@broadcom.com> Cc: Michael Chan <mchan@broadcom.com> Signed-off-by:

Ivan Vecera <ivecera@redhat.com> Acked-by:

Michael Chan <mchan@broadcom.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/tg3.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -6862,12 +6862,6 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget)
		pci_unmap_single(tp->pdev, dma_addr, skb_size,
		PCI_DMA_FROMDEVICE);

		skb = build_skb(data, frag_size);
		if (!skb) {
		tg3_frag_free(frag_size != 0, data);
		goto drop_it_no_recycle;
		}
		skb_reserve(skb, TG3_RX_OFFSET(tp));
		/* Ensure that the update to the data happens
		* after the usage of the old DMA mapping.
		*/
		@@ -6875,6 +6869,12 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget)

		ri->data = NULL;

		skb = build_skb(data, frag_size);
		if (!skb) {
		tg3_frag_free(frag_size != 0, data);
		goto drop_it_no_recycle;
		}
		skb_reserve(skb, TG3_RX_OFFSET(tp));
		} else {
		tg3_recycle_rx(tnapi, tpr, opaque_key,
		desc_idx, *post_ptr);

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