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* [PATCH net] net: mana: Fix Rx DMA datasize and skb_over_panic
@ 2024-03-29 21:36 Haiyang Zhang
  2024-03-29 21:36 ` Haiyang Zhang
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Haiyang Zhang @ 2024-03-29 21:36 UTC (permalink / raw)
  To: linux-hyperv, netdev
  Cc: haiyangz, decui, stephen, kys, paulros, olaf, vkuznets, davem,
	wei.liu, edumazet, kuba, pabeni, leon, longli, ssengar,
	linux-rdma, daniel, john.fastabend, bpf, ast, sharmaajay, hawk,
	tglx, shradhagupta, linux-kernel, stable

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: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 2 +-
 include/net/mana/mana.h                       | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 59287c6e6cee..d8af5e7e15b4 100644
--- 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 76147feb0d10..4eeedf14711b 100644
--- 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
 
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2024-04-02 15:59 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-03-29 21:36 [PATCH net] net: mana: Fix Rx DMA datasize and skb_over_panic Haiyang Zhang
2024-03-29 21:36 ` Haiyang Zhang
2024-03-29 21:36 ` Haiyang Zhang
2024-03-30  0:12 ` Dexuan Cui
2024-04-01 23:21   ` Haiyang Zhang
2024-04-02  1:23     ` Dexuan Cui
2024-04-02  4:12       ` Jakub Kicinski
2024-04-02 15:59         ` Haiyang Zhang

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