lkml.org 
[lkml]   [2019]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 106/293] iavf: fix dereference of null rx_buffer pointer
Date
[ Upstream commit 9fe06a51287b2d41baef7ece94df34b5abf19b90 ]

A recent commit efa14c3985828d ("iavf: allow null RX descriptors") added
a null pointer sanity check on rx_buffer, however, rx_buffer is being
dereferenced before that check, which implies a null pointer dereference
bug can potentially occur. Fix this by only dereferencing rx_buffer
until after the null pointer check.

Addresses-Coverity: ("Dereference before null check")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 7368b0dc3af8..4afdabbe95e8 100644
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -1117,7 +1117,7 @@ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring,
struct i40e_rx_buffer *rx_buffer,
unsigned int size)
{
- void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
+ void *va;
#if (PAGE_SIZE < 8192)
unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
#else
@@ -1127,6 +1127,7 @@ static struct sk_buff *i40e_construct_skb(struct i40e_ring *rx_ring,
struct sk_buff *skb;

/* prefetch first cache line of first page */
+ va = page_address(rx_buffer->page) + rx_buffer->page_offset;
prefetch(va);
#if L1_CACHE_BYTES < 128
prefetch(va + L1_CACHE_BYTES);
@@ -1181,7 +1182,7 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
struct i40e_rx_buffer *rx_buffer,
unsigned int size)
{
- void *va = page_address(rx_buffer->page) + rx_buffer->page_offset;
+ void *va;
#if (PAGE_SIZE < 8192)
unsigned int truesize = i40e_rx_pg_size(rx_ring) / 2;
#else
@@ -1191,6 +1192,7 @@ static struct sk_buff *i40e_build_skb(struct i40e_ring *rx_ring,
struct sk_buff *skb;

/* prefetch first cache line of first page */
+ va = page_address(rx_buffer->page) + rx_buffer->page_offset;
prefetch(va);
#if L1_CACHE_BYTES < 128
prefetch(va + L1_CACHE_BYTES);
--
2.20.1


\
 
 \ /
  Last update: 2019-07-29 21:39    [W:0.817 / U:1.184 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site