net: mana: Fix Rx DMA datasize and skb_over_panic

commit c0de6ab920aafb56feab56058e46b688e694a246 upstream.

mana_get_rxbuf_cfg() aligns the RX buffer's DMA datasize to be
multiple of 64. So a packet slightly bigger than mtu+14, say 1536,
can be received and cause skb_over_panic.

Sample dmesg:
[ 5325.237162] skbuff: skb_over_panic: text:ffffffffc043277a len:1536 put:1536 head:ff1100018b517000 data:ff1100018b517100 tail:0x700 end:0x6ea dev:<NULL>
[ 5325.243689] ------------[ cut here ]------------
[ 5325.245748] kernel BUG at net/core/skbuff.c:192!
[ 5325.247838] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 5325.258374] RIP: 0010:skb_panic+0x4f/0x60
[ 5325.302941] Call Trace:
[ 5325.304389]  <IRQ>
[ 5325.315794]  ? skb_panic+0x4f/0x60
[ 5325.317457]  ? asm_exc_invalid_op+0x1f/0x30
[ 5325.319490]  ? skb_panic+0x4f/0x60
[ 5325.321161]  skb_put+0x4e/0x50
[ 5325.322670]  mana_poll+0x6fa/0xb50 [mana]
[ 5325.324578]  __napi_poll+0x33/0x1e0
[ 5325.326328]  net_rx_action+0x12e/0x280

As discussed internally, this alignment is not necessary. To fix
this bug, remove it from the code. So oversized packets will be
marked as CQE_RX_TRUNCATED by NIC, and dropped.

Cc: stable@vger.kernel.org
Fixes: 2fbbd712baf1 ("net: mana: Enable RX path to handle various MTU sizes")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/1712087316-20886-1-git-send-email-haiyangz@microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 48ea4aeeea5d4c95f98317d8c712b0c7fc353c13..e443d69e395113a8762f8f40e257ad2e77f6cfc0 100644 (file)
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -601,7 +601,7 @@ static void mana_get_rxbuf_cfg(int mtu, u32 *datasize, u32 *alloc_size,
 
        *alloc_size = mtu + MANA_RXBUF_PAD + *headroom;
 
-       *datasize = ALIGN(mtu + ETH_HLEN, MANA_RX_DATA_ALIGN);
+       *datasize = mtu + ETH_HLEN;
 }
 
 static int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu)

diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index 4d43adf186064c4de216d6f83bdf4916a7b07877..cd526fd31b4584f1fc6a2b1f63107b81fd7777e6 100644 (file)
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -39,7 +39,6 @@ enum TRI_STATE {
 #define COMP_ENTRY_SIZE 64
 
 #define RX_BUFFERS_PER_QUEUE 512
-#define MANA_RX_DATA_ALIGN 64
 
 #define MAX_SEND_BUFFERS_PER_QUEUE 256