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authorBjörn Töpel <bjorn.topel@intel.com>2020-08-25 19:27:35 +0200
committerTony Nguyen <anthony.l.nguyen@intel.com>2020-12-09 15:26:58 -0800
commita06316dc87bdc000f7f39a315476957af2ba0f05 (patch)
tree6d1e9914dde4ff01a0c96dd856467d35999d1bf1
parent75aab4e10ae6a4593a60f66d13de755d4e91f400 (diff)
downloadlinux-fullhistory-a06316dc87bdc000f7f39a315476957af2ba0f05.tar.gz
ixgbe: avoid premature Rx buffer reuse
The page recycle code, incorrectly, relied on that a page fragment could not be freed inside xdp_do_redirect(). This assumption leads to that page fragments that are used by the stack/XDP redirect can be reused and overwritten. To avoid this, store the page count prior invoking xdp_do_redirect(). Fixes: 6453073987ba ("ixgbe: add initial support for xdp redirect") Reported-and-analyzed-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Björn Töpel <bjorn.topel@intel.com> Tested-by: Sandeep Penigalapati <sandeep.penigalapati@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
-rw-r--r--drivers/net/ethernet/intel/ixgbe/ixgbe_main.c24
1 files changed, 17 insertions, 7 deletions
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 45ae33e1530384..f3f449f53920f3 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1945,7 +1945,8 @@ static inline bool ixgbe_page_is_reserved(struct page *page)
return (page_to_nid(page) != numa_mem_id()) || page_is_pfmemalloc(page);
}
-static bool ixgbe_can_reuse_rx_page(struct ixgbe_rx_buffer *rx_buffer)
+static bool ixgbe_can_reuse_rx_page(struct ixgbe_rx_buffer *rx_buffer,
+ int rx_buffer_pgcnt)
{
unsigned int pagecnt_bias = rx_buffer->pagecnt_bias;
struct page *page = rx_buffer->page;
@@ -1956,7 +1957,7 @@ static bool ixgbe_can_reuse_rx_page(struct ixgbe_rx_buffer *rx_buffer)
#if (PAGE_SIZE < 8192)
/* if we are only owner of page we can reuse it */
- if (unlikely((page_ref_count(page) - pagecnt_bias) > 1))
+ if (unlikely((rx_buffer_pgcnt - pagecnt_bias) > 1))
return false;
#else
/* The last offset is a bit aggressive in that we assume the
@@ -2021,11 +2022,18 @@ static void ixgbe_add_rx_frag(struct ixgbe_ring *rx_ring,
static struct ixgbe_rx_buffer *ixgbe_get_rx_buffer(struct ixgbe_ring *rx_ring,
union ixgbe_adv_rx_desc *rx_desc,
struct sk_buff **skb,
- const unsigned int size)
+ const unsigned int size,
+ int *rx_buffer_pgcnt)
{
struct ixgbe_rx_buffer *rx_buffer;
rx_buffer = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
+ *rx_buffer_pgcnt =
+#if (PAGE_SIZE < 8192)
+ page_count(rx_buffer->page);
+#else
+ 0;
+#endif
prefetchw(rx_buffer->page);
*skb = rx_buffer->skb;
@@ -2055,9 +2063,10 @@ skip_sync:
static void ixgbe_put_rx_buffer(struct ixgbe_ring *rx_ring,
struct ixgbe_rx_buffer *rx_buffer,
- struct sk_buff *skb)
+ struct sk_buff *skb,
+ int rx_buffer_pgcnt)
{
- if (ixgbe_can_reuse_rx_page(rx_buffer)) {
+ if (ixgbe_can_reuse_rx_page(rx_buffer, rx_buffer_pgcnt)) {
/* hand second half of page back to the ring */
ixgbe_reuse_rx_page(rx_ring, rx_buffer);
} else {
@@ -2303,6 +2312,7 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
union ixgbe_adv_rx_desc *rx_desc;
struct ixgbe_rx_buffer *rx_buffer;
struct sk_buff *skb;
+ int rx_buffer_pgcnt;
unsigned int size;
/* return some buffers to hardware, one at a time is too slow */
@@ -2322,7 +2332,7 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
*/
dma_rmb();
- rx_buffer = ixgbe_get_rx_buffer(rx_ring, rx_desc, &skb, size);
+ rx_buffer = ixgbe_get_rx_buffer(rx_ring, rx_desc, &skb, size, &rx_buffer_pgcnt);
/* retrieve a buffer from the ring */
if (!skb) {
@@ -2367,7 +2377,7 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
break;
}
- ixgbe_put_rx_buffer(rx_ring, rx_buffer, skb);
+ ixgbe_put_rx_buffer(rx_ring, rx_buffer, skb, rx_buffer_pgcnt);
cleaned_count++;
/* place incomplete frames back on ring for completion */