--- /dev/null
+From d8861bab48b6c1fc3cdbcab8ff9d1eaea43afe7f Mon Sep 17 00:00:00 2001
+From: Michael Braun <michael-dev@fami-braun.de>
+Date: Thu, 4 Mar 2021 20:52:52 +0100
+Subject: gianfar: fix jumbo packets+napi+rx overrun crash
+
+From: Michael Braun <michael-dev@fami-braun.de>
+
+commit d8861bab48b6c1fc3cdbcab8ff9d1eaea43afe7f upstream.
+
+When using jumbo packets and overrunning rx queue with napi enabled,
+the following sequence is observed in gfar_add_rx_frag:
+
+ | lstatus | | skb |
+t | lstatus, size, flags | first | len, data_len, *ptr |
+---+--------------------------------------+-------+-----------------------+
+13 | 18002348, 9032, INTERRUPT LAST | 0 | 9600, 8000, f554c12e |
+12 | 10000640, 1600, INTERRUPT | 0 | 8000, 6400, f554c12e |
+11 | 10000640, 1600, INTERRUPT | 0 | 6400, 4800, f554c12e |
+10 | 10000640, 1600, INTERRUPT | 0 | 4800, 3200, f554c12e |
+09 | 10000640, 1600, INTERRUPT | 0 | 3200, 1600, f554c12e |
+08 | 14000640, 1600, INTERRUPT FIRST | 0 | 1600, 0, f554c12e |
+07 | 14000640, 1600, INTERRUPT FIRST | 1 | 0, 0, f554c12e |
+06 | 1c000080, 128, INTERRUPT LAST FIRST | 1 | 0, 0, abf3bd6e |
+05 | 18002348, 9032, INTERRUPT LAST | 0 | 8000, 6400, c5a57780 |
+04 | 10000640, 1600, INTERRUPT | 0 | 6400, 4800, c5a57780 |
+03 | 10000640, 1600, INTERRUPT | 0 | 4800, 3200, c5a57780 |
+02 | 10000640, 1600, INTERRUPT | 0 | 3200, 1600, c5a57780 |
+01 | 10000640, 1600, INTERRUPT | 0 | 1600, 0, c5a57780 |
+00 | 14000640, 1600, INTERRUPT FIRST | 1 | 0, 0, c5a57780 |
+
+So at t=7 a new packets is started but not finished, probably due to rx
+overrun - but rx overrun is not indicated in the flags. Instead a new
+packets starts at t=8. This results in skb->len to exceed size for the LAST
+fragment at t=13 and thus a negative fragment size added to the skb.
+
+This then crashes:
+
+kernel BUG at include/linux/skbuff.h:2277!
+Oops: Exception in kernel mode, sig: 5 [#1]
+...
+NIP [c04689f4] skb_pull+0x2c/0x48
+LR [c03f62ac] gfar_clean_rx_ring+0x2e4/0x844
+Call Trace:
+[ec4bfd38] [c06a84c4] _raw_spin_unlock_irqrestore+0x60/0x7c (unreliable)
+[ec4bfda8] [c03f6a44] gfar_poll_rx_sq+0x48/0xe4
+[ec4bfdc8] [c048d504] __napi_poll+0x54/0x26c
+[ec4bfdf8] [c048d908] net_rx_action+0x138/0x2c0
+[ec4bfe68] [c06a8f34] __do_softirq+0x3a4/0x4fc
+[ec4bfed8] [c0040150] run_ksoftirqd+0x58/0x70
+[ec4bfee8] [c0066ecc] smpboot_thread_fn+0x184/0x1cc
+[ec4bff08] [c0062718] kthread+0x140/0x144
+[ec4bff38] [c0012350] ret_from_kernel_thread+0x14/0x1c
+
+This patch fixes this by checking for computed LAST fragment size, so a
+negative sized fragment is never added.
+In order to prevent the newer rx frame from getting corrupted, the FIRST
+flag is checked to discard the incomplete older frame.
+
+Signed-off-by: Michael Braun <michael-dev@fami-braun.de>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Cc: Ben Hutchings <ben@decadent.org.uk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/net/ethernet/freescale/gianfar.c | 15 +++++++++++++++
+ 1 file changed, 15 insertions(+)
+
+--- a/drivers/net/ethernet/freescale/gianfar.c
++++ b/drivers/net/ethernet/freescale/gianfar.c
+@@ -2947,6 +2947,10 @@ static bool gfar_add_rx_frag(struct gfar
+ if (lstatus & BD_LFLAG(RXBD_LAST))
+ size -= skb->len;
+
++ WARN(size < 0, "gianfar: rx fragment size underflow");
++ if (size < 0)
++ return false;
++
+ skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
+ rxb->page_offset + RXBUF_ALIGNMENT,
+ size, GFAR_RXB_TRUESIZE);
+@@ -3108,6 +3112,17 @@ int gfar_clean_rx_ring(struct gfar_priv_
+ if (lstatus & BD_LFLAG(RXBD_EMPTY))
+ break;
+
++ /* lost RXBD_LAST descriptor due to overrun */
++ if (skb &&
++ (lstatus & BD_LFLAG(RXBD_FIRST))) {
++ /* discard faulty buffer */
++ dev_kfree_skb(skb);
++ skb = NULL;
++ rx_queue->stats.rx_dropped++;
++
++ /* can continue normally */
++ }
++
+ /* order rx buffer descriptor reads */
+ rmb();
+
--- /dev/null
+From d903ec77118c09f93a610b384d83a6df33a64fe6 Mon Sep 17 00:00:00 2001
+From: Andy Spencer <aspencer@spacex.com>
+Date: Thu, 22 Feb 2018 11:05:33 -0800
+Subject: gianfar: simplify FCS handling and fix memory leak
+
+From: Andy Spencer <aspencer@spacex.com>
+
+commit d903ec77118c09f93a610b384d83a6df33a64fe6 upstream.
+
+Previously, buffer descriptors containing only the frame check sequence
+(FCS) were skipped and not added to the skb. However, the page reference
+count was still incremented, leading to a memory leak.
+
+Fixing this inside gfar_add_rx_frag() is difficult due to reserved
+memory handling and page reuse. Instead, move the FCS handling to
+gfar_process_frame() and trim off the FCS before passing the skb up the
+networking stack.
+
+Signed-off-by: Andy Spencer <aspencer@spacex.com>
+Signed-off-by: Jim Gruen <jgruen@spacex.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Cc: Ben Hutchings <ben@decadent.org.uk>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/net/ethernet/freescale/gianfar.c | 23 +++++++----------------
+ 1 file changed, 7 insertions(+), 16 deletions(-)
+
+--- a/drivers/net/ethernet/freescale/gianfar.c
++++ b/drivers/net/ethernet/freescale/gianfar.c
+@@ -2939,29 +2939,17 @@ static bool gfar_add_rx_frag(struct gfar
+ {
+ int size = lstatus & BD_LENGTH_MASK;
+ struct page *page = rxb->page;
+- bool last = !!(lstatus & BD_LFLAG(RXBD_LAST));
+-
+- /* Remove the FCS from the packet length */
+- if (last)
+- size -= ETH_FCS_LEN;
+
+ if (likely(first)) {
+ skb_put(skb, size);
+ } else {
+ /* the last fragments' length contains the full frame length */
+- if (last)
++ if (lstatus & BD_LFLAG(RXBD_LAST))
+ size -= skb->len;
+
+- /* Add the last fragment if it contains something other than
+- * the FCS, otherwise drop it and trim off any part of the FCS
+- * that was already received.
+- */
+- if (size > 0)
+- skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
+- rxb->page_offset + RXBUF_ALIGNMENT,
+- size, GFAR_RXB_TRUESIZE);
+- else if (size < 0)
+- pskb_trim(skb, skb->len + size);
++ skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page,
++ rxb->page_offset + RXBUF_ALIGNMENT,
++ size, GFAR_RXB_TRUESIZE);
+ }
+
+ /* try reuse page */
+@@ -3074,6 +3062,9 @@ static void gfar_process_frame(struct ne
+ if (priv->padding)
+ skb_pull(skb, priv->padding);
+
++ /* Trim off the FCS */
++ pskb_trim(skb, skb->len - ETH_FCS_LEN);
++
+ if (ndev->features & NETIF_F_RXCSUM)
+ gfar_rx_checksum(skb, fcb);
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
