From: Song Yoong Siang <yoong.siang.song@xxxxxxxxx>
commit 2b9fff64f03219d78044d1ab40dde8e3d42e968a upstream.
Ensure a valid XSK buffer before proceed to free the xdp buffer.
The following kernel panic is observed without this patch:
RIP: 0010:xp_free+0x5/0x40
Call Trace:
stmmac_napi_poll_rxtx+0x332/0xb30 [stmmac]
? stmmac_tx_timer+0x3c/0xb0 [stmmac]
net_rx_action+0x13d/0x3d0
__do_softirq+0xfc/0x2fb
? smpboot_register_percpu_thread+0xe0/0xe0
run_ksoftirqd+0x32/0x70
smpboot_thread_fn+0x1d8/0x2c0
kthread+0x169/0x1a0
? kthread_park+0x90/0x90
ret_from_fork+0x1f/0x30
---[ end trace 0000000000000002 ]---
Fixes: bba2556efad6 ("net: stmmac: Enable RX via AF_XDP zero-copy")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.13.x
Suggested-by: Ong Boon Leong <boon.leong.ong@xxxxxxxxx>
Signed-off-by: Song Yoong Siang <yoong.siang.song@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4925,6 +4925,10 @@ read_again:
prefetch(np);
+ /* Ensure a valid XSK buffer before proceed */
+ if (!buf->xdp)
+ break;
+
if (priv->extend_desc)
stmmac_rx_extended_status(priv, &priv->dev->stats,
&priv->xstats,
@@ -4945,10 +4949,6 @@ read_again:
continue;
}
- /* Ensure a valid XSK buffer before proceed */
- if (!buf->xdp)
- break;
-
/* XSK pool expects RX frame 1:1 mapped to XSK buffer */
if (likely(status & rx_not_ls)) {
xsk_buff_free(buf->xdp);
