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[Qemu-devel] [PATCH 015/156] hw/net/stellaris_enet: Restructure tx_fifo
From: |
Michael Roth |
Subject: |
[Qemu-devel] [PATCH 015/156] hw/net/stellaris_enet: Restructure tx_fifo code to avoid buffer overrun |
Date: |
Tue, 8 Jul 2014 12:16:46 -0500 |
From: Peter Maydell <address@hidden>
The current tx_fifo code has a corner case where the guest can overrun
the fifo buffer: if automatic CRCs are disabled we allow the guest to write
the CRC word even if there isn't actually space for it in the FIFO.
The datasheet is unclear about exactly how the hardware deals with this
situation; the most plausible answer seems to be that the CRC word is
just lost.
Implement this fix by separating the "can we stuff another word in the
FIFO" logic from the "should we transmit the packet now" check. This
also moves us closer to the real hardware, which has a number of ways
it can be configured to trigger sending the packet, some of which we
don't implement.
Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
Cc: address@hidden
(cherry picked from commit 5c10495ab1546d5d12b51a97817051e9ec98d0f6)
Signed-off-by: Michael Roth <address@hidden>
---
hw/net/stellaris_enet.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/hw/net/stellaris_enet.c b/hw/net/stellaris_enet.c
index 9dd77f7..8a1d0d1 100644
--- a/hw/net/stellaris_enet.c
+++ b/hw/net/stellaris_enet.c
@@ -252,10 +252,12 @@ static void stellaris_enet_write(void *opaque, hwaddr
offset,
s->tx_fifo[s->tx_fifo_len++] = value >> 24;
}
} else {
- s->tx_fifo[s->tx_fifo_len++] = value;
- s->tx_fifo[s->tx_fifo_len++] = value >> 8;
- s->tx_fifo[s->tx_fifo_len++] = value >> 16;
- s->tx_fifo[s->tx_fifo_len++] = value >> 24;
+ if (s->tx_fifo_len + 4 <= ARRAY_SIZE(s->tx_fifo)) {
+ s->tx_fifo[s->tx_fifo_len++] = value;
+ s->tx_fifo[s->tx_fifo_len++] = value >> 8;
+ s->tx_fifo[s->tx_fifo_len++] = value >> 16;
+ s->tx_fifo[s->tx_fifo_len++] = value >> 24;
+ }
if (s->tx_fifo_len >= s->tx_frame_len) {
/* We don't implement explicit CRC, so just chop it off. */
if ((s->tctl & SE_TCTL_CRC) == 0)
--
1.9.1
- [Qemu-devel] [PATCH 082/156] vpc/vhd: add bounds check for max_table_entries and block_size (CVE-2014-0144), (continued)
- [Qemu-devel] [PATCH 082/156] vpc/vhd: add bounds check for max_table_entries and block_size (CVE-2014-0144), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 152/156] qapi: zero-initialize all QMP command parameters, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 023/156] block: Use BDRV_O_NO_BACKING where appropriate, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 140/156] scsi-disk: fix bug in scsi_block_new_request() introduced by commit 137745c, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 067/156] migration: remove duplicate code, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 092/156] qcow2: Validate active L1 table offset and size (CVE-2014-0144), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 009/156] tap: avoid deadlocking rx, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 008/156] qom: Avoid leaking str and bool properties on failure, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 011/156] configure: Don't use __int128_t for clang versions before 3.2, Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 114/156] parallels: Fix catalog size integer overflow (CVE-2014-0143), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 015/156] hw/net/stellaris_enet: Restructure tx_fifo code to avoid buffer overrun,
Michael Roth <=
- [Qemu-devel] [PATCH 119/156] qcow1: Validate image size (CVE-2014-0223), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 118/156] qcow1: Validate L2 table size (CVE-2014-0222), Michael Roth, 2014/07/08
- [Qemu-devel] [PATCH 090/156] qcow2: Validate refcount table offset, Michael Roth, 2014/07/09
- [Qemu-devel] [PATCH 138/156] qga: Fix handle fd leak in acquire_privilege(), Michael Roth, 2014/07/09
- [Qemu-devel] [PATCH 121/156] virtio-scsi: Plug memory leak on virtio_scsi_push_event() error path, Michael Roth, 2014/07/09
- [Qemu-devel] [PATCH 044/156] vmstate: fix buffer overflow in target-arm/machine.c, Michael Roth, 2014/07/09
- [Qemu-devel] [PATCH 112/156] qcow2: Fix L1 allocation size in qcow2_snapshot_load_tmp() (CVE-2014-0145), Michael Roth, 2014/07/09
- [Qemu-devel] [PATCH 147/156] virtio-serial: don't migrate the config space, Michael Roth, 2014/07/09
- Re: [Qemu-devel] Patch Round-up for stable 1.7.2, freeze on 2014-07-14, Dr. David Alan Gilbert, 2014/07/09