From d723a57acd985cf5c9fdf8a2761d1ca53a3179c0 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Sun, 26 Apr 2020 12:55:39 +0200 Subject: [PATCH] Fix tulip breakage The tulip network driver in a qemu-system-hppa emulation is broken in the sense that bigger network packages aren't received any longer and thus even running e.g. "apt update" inside the VM fails. The breakage was introduced by commit 8ffb7265af ("check frame size and r/w data length") which added checks to prevent accesses outside of the rx/tx buffers. But the new checks were implemented wrong. The variable rx_frame_len counts backwards, from rx_frame_size down to zero, and the variable len is never bigger than rx_frame_len, so accesses just can't happen and the checks are unnecessary. On the contrary the checks now prevented bigger packages to be moved into the rx buffers. This patch reverts the wrong checks and were sucessfully tested with a qemu-system-hppa emulation. Fixes: 8ffb7265af ("check frame size and r/w data length") Buglink: https://bugs.launchpad.net/bugs/1874539 Signed-off-by: Helge Deller Signed-off-by: Jason Wang (cherry picked from commit d9b69640391618045949f7c500b87fc129f862ed) Signed-off-by: Michael Roth --- hw/net/tulip.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/hw/net/tulip.c b/hw/net/tulip.c index 1295f51d07..44db56447c 100644 --- a/hw/net/tulip.c +++ b/hw/net/tulip.c @@ -171,9 +171,6 @@ static void tulip_copy_rx_bytes(TULIPState *s, struct tulip_descriptor *desc) len = s->rx_frame_len; } - if (s->rx_frame_len + len > sizeof(s->rx_frame)) { - return; - } pci_dma_write(&s->dev, desc->buf_addr1, s->rx_frame + (s->rx_frame_size - s->rx_frame_len), len); s->rx_frame_len -= len; @@ -186,9 +183,6 @@ static void tulip_copy_rx_bytes(TULIPState *s, struct tulip_descriptor *desc) len = s->rx_frame_len; } - if (s->rx_frame_len + len > sizeof(s->rx_frame)) { - return; - } pci_dma_write(&s->dev, desc->buf_addr2, s->rx_frame + (s->rx_frame_size - s->rx_frame_len), len); s->rx_frame_len -= len; -- 2.39.5