[Qemu-devel] [PATCH stable-0.15 05/36] e1000: bounds packet size against buffer size

[Andreas Färber]

From: Anthony Liguori <address@hidden>

Otherwise we can write beyond the buffer and corrupt memory.  This is tracked
as CVE-2012-0029.

Signed-off-by: Anthony Liguori <address@hidden>
(cherry picked from commit 65f82df0d7a71ce1b10cd4c5ab08888d176ac840)

Signed-off-by: Bruce Rogers <address@hidden>
[AF: stable-0.15 does not have pci_dma_read(). Fixes BNC#740165.]
Signed-off-by: Andreas Färber <address@hidden>
---
 hw/e1000.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/hw/e1000.c b/hw/e1000.c
index 7971457..c91790b 100644
--- a/hw/e1000.c
+++ b/hw/e1000.c
@@ -472,6 +472,8 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp)
             bytes = split_size;
             if (tp->size + bytes > msh)
                 bytes = msh - tp->size;
+
+            bytes = MIN(sizeof(tp->data) - tp->size, bytes);
             cpu_physical_memory_read(addr, tp->data + tp->size, bytes);
             if ((sz = tp->size + bytes) >= hdr && tp->size < hdr)
                 memmove(tp->header, tp->data, hdr);
@@ -487,6 +489,7 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp)
         // context descriptor TSE is not set, while data descriptor TSE is set
         DBGOUT(TXERR, "TCP segmentaion Error\n");
     } else {
+        split_size = MIN(sizeof(tp->data) - tp->size, split_size);
         cpu_physical_memory_read(addr, tp->data + tp->size, split_size);
         tp->size += split_size;
     }
-- 
1.7.7