* [PATCH 5.4 07/74] r8169: fix the KCSAN reported data-race in rtl_tx while reading TxDescArray[entry].opts1
[not found] <20231106130301.687882731@linuxfoundation.org>
@ 2023-11-06 13:03 ` Greg Kroah-Hartman
2023-11-06 13:03 ` [PATCH 5.4 08/74] r8169: fix the KCSAN reported data race in rtl_rx while reading desc->opts1 Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2023-11-06 13:03 UTC (permalink / raw)
To: stable
Cc: Greg Kroah-Hartman, patches, Heiner Kallweit, nic_swsd,
David S. Miller, Eric Dumazet, Jakub Kicinski, Paolo Abeni,
Marco Elver, netdev, Mirsad Goran Todorovac, Sasha Levin
5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
[ Upstream commit dcf75a0f6bc136de94e88178ae5f51b7f879abc9 ]
KCSAN reported the following data-race:
==================================================================
BUG: KCSAN: data-race in rtl8169_poll (drivers/net/ethernet/realtek/r8169_main.c:4368 drivers/net/ethernet/realtek/r8169_main.c:4581) r8169
race at unknown origin, with read to 0xffff888140d37570 of 4 bytes by interrupt on cpu 21:
rtl8169_poll (drivers/net/ethernet/realtek/r8169_main.c:4368 drivers/net/ethernet/realtek/r8169_main.c:4581) r8169
__napi_poll (net/core/dev.c:6527)
net_rx_action (net/core/dev.c:6596 net/core/dev.c:6727)
__do_softirq (kernel/softirq.c:553)
__irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632)
irq_exit_rcu (kernel/softirq.c:647)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1074 (discriminator 14))
asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:645)
cpuidle_enter_state (drivers/cpuidle/cpuidle.c:291)
cpuidle_enter (drivers/cpuidle/cpuidle.c:390)
call_cpuidle (kernel/sched/idle.c:135)
do_idle (kernel/sched/idle.c:219 kernel/sched/idle.c:282)
cpu_startup_entry (kernel/sched/idle.c:378 (discriminator 1))
start_secondary (arch/x86/kernel/smpboot.c:210 arch/x86/kernel/smpboot.c:294)
secondary_startup_64_no_verify (arch/x86/kernel/head_64.S:433)
value changed: 0xb0000042 -> 0x00000000
Reported by Kernel Concurrency Sanitizer on:
CPU: 21 PID: 0 Comm: swapper/21 Tainted: G L 6.6.0-rc2-kcsan-00143-gb5cbe7c00aa0 #41
Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023
==================================================================
The read side is in
drivers/net/ethernet/realtek/r8169_main.c
=========================================
4355 static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp,
4356 int budget)
4357 {
4358 unsigned int dirty_tx, bytes_compl = 0, pkts_compl = 0;
4359 struct sk_buff *skb;
4360
4361 dirty_tx = tp->dirty_tx;
4362
4363 while (READ_ONCE(tp->cur_tx) != dirty_tx) {
4364 unsigned int entry = dirty_tx % NUM_TX_DESC;
4365 u32 status;
4366
→ 4367 status = le32_to_cpu(tp->TxDescArray[entry].opts1);
4368 if (status & DescOwn)
4369 break;
4370
4371 skb = tp->tx_skb[entry].skb;
4372 rtl8169_unmap_tx_skb(tp, entry);
4373
4374 if (skb) {
4375 pkts_compl++;
4376 bytes_compl += skb->len;
4377 napi_consume_skb(skb, budget);
4378 }
4379 dirty_tx++;
4380 }
4381
4382 if (tp->dirty_tx != dirty_tx) {
4383 dev_sw_netstats_tx_add(dev, pkts_compl, bytes_compl);
4384 WRITE_ONCE(tp->dirty_tx, dirty_tx);
4385
4386 netif_subqueue_completed_wake(dev, 0, pkts_compl, bytes_compl,
4387 rtl_tx_slots_avail(tp),
4388 R8169_TX_START_THRS);
4389 /*
4390 * 8168 hack: TxPoll requests are lost when the Tx packets are
4391 * too close. Let's kick an extra TxPoll request when a burst
4392 * of start_xmit activity is detected (if it is not detected,
4393 * it is slow enough). -- FR
4394 * If skb is NULL then we come here again once a tx irq is
4395 * triggered after the last fragment is marked transmitted.
4396 */
4397 if (READ_ONCE(tp->cur_tx) != dirty_tx && skb)
4398 rtl8169_doorbell(tp);
4399 }
4400 }
tp->TxDescArray[entry].opts1 is reported to have a data-race and READ_ONCE() fixes
this KCSAN warning.
4366
→ 4367 status = le32_to_cpu(READ_ONCE(tp->TxDescArray[entry].opts1));
4368 if (status & DescOwn)
4369 break;
4370
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: nic_swsd@realtek.com
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/lkml/dc7fc8fa-4ea4-e9a9-30a6-7c83e6b53188@alu.unizg.hr/
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Acked-by: Marco Elver <elver@google.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/realtek/r8169_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 8d2b184ff5758..b973198da96c3 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -6031,7 +6031,7 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp,
struct ring_info *tx_skb = tp->tx_skb + entry;
u32 status;
- status = le32_to_cpu(tp->TxDescArray[entry].opts1);
+ status = le32_to_cpu(READ_ONCE(tp->TxDescArray[entry].opts1));
if (status & DescOwn)
break;
--
2.42.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH 5.4 08/74] r8169: fix the KCSAN reported data race in rtl_rx while reading desc->opts1
[not found] <20231106130301.687882731@linuxfoundation.org>
2023-11-06 13:03 ` [PATCH 5.4 07/74] r8169: fix the KCSAN reported data-race in rtl_tx while reading TxDescArray[entry].opts1 Greg Kroah-Hartman
@ 2023-11-06 13:03 ` Greg Kroah-Hartman
1 sibling, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2023-11-06 13:03 UTC (permalink / raw)
To: stable
Cc: Greg Kroah-Hartman, patches, Marco Elver, Heiner Kallweit,
nic_swsd, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, netdev, Mirsad Goran Todorovac, Sasha Levin
5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
[ Upstream commit f97eee484e71890131f9c563c5cc6d5a69e4308d ]
KCSAN reported the following data-race bug:
==================================================================
BUG: KCSAN: data-race in rtl8169_poll (drivers/net/ethernet/realtek/r8169_main.c:4430 drivers/net/ethernet/realtek/r8169_main.c:4583) r8169
race at unknown origin, with read to 0xffff888117e43510 of 4 bytes by interrupt on cpu 21:
rtl8169_poll (drivers/net/ethernet/realtek/r8169_main.c:4430 drivers/net/ethernet/realtek/r8169_main.c:4583) r8169
__napi_poll (net/core/dev.c:6527)
net_rx_action (net/core/dev.c:6596 net/core/dev.c:6727)
__do_softirq (kernel/softirq.c:553)
__irq_exit_rcu (kernel/softirq.c:427 kernel/softirq.c:632)
irq_exit_rcu (kernel/softirq.c:647)
sysvec_apic_timer_interrupt (arch/x86/kernel/apic/apic.c:1074 (discriminator 14))
asm_sysvec_apic_timer_interrupt (./arch/x86/include/asm/idtentry.h:645)
cpuidle_enter_state (drivers/cpuidle/cpuidle.c:291)
cpuidle_enter (drivers/cpuidle/cpuidle.c:390)
call_cpuidle (kernel/sched/idle.c:135)
do_idle (kernel/sched/idle.c:219 kernel/sched/idle.c:282)
cpu_startup_entry (kernel/sched/idle.c:378 (discriminator 1))
start_secondary (arch/x86/kernel/smpboot.c:210 arch/x86/kernel/smpboot.c:294)
secondary_startup_64_no_verify (arch/x86/kernel/head_64.S:433)
value changed: 0x80003fff -> 0x3402805f
Reported by Kernel Concurrency Sanitizer on:
CPU: 21 PID: 0 Comm: swapper/21 Tainted: G L 6.6.0-rc2-kcsan-00143-gb5cbe7c00aa0 #41
Hardware name: ASRock X670E PG Lightning/X670E PG Lightning, BIOS 1.21 04/26/2023
==================================================================
drivers/net/ethernet/realtek/r8169_main.c:
==========================================
4429
→ 4430 status = le32_to_cpu(desc->opts1);
4431 if (status & DescOwn)
4432 break;
4433
4434 /* This barrier is needed to keep us from reading
4435 * any other fields out of the Rx descriptor until
4436 * we know the status of DescOwn
4437 */
4438 dma_rmb();
4439
4440 if (unlikely(status & RxRES)) {
4441 if (net_ratelimit())
4442 netdev_warn(dev, "Rx ERROR. status = %08x\n",
Marco Elver explained that dma_rmb() doesn't prevent the compiler to tear up the access to
desc->opts1 which can be written to concurrently. READ_ONCE() should prevent that from
happening:
4429
→ 4430 status = le32_to_cpu(READ_ONCE(desc->opts1));
4431 if (status & DescOwn)
4432 break;
4433
As the consequence of this fix, this KCSAN warning was eliminated.
Fixes: 6202806e7c03a ("r8169: drop member opts1_mask from struct rtl8169_private")
Suggested-by: Marco Elver <elver@google.com>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: nic_swsd@realtek.com
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/lkml/dc7fc8fa-4ea4-e9a9-30a6-7c83e6b53188@alu.unizg.hr/
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Acked-by: Marco Elver <elver@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/realtek/r8169_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index b973198da96c3..fca2dbdd37aff 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -6114,7 +6114,7 @@ static int rtl_rx(struct net_device *dev, struct rtl8169_private *tp, u32 budget
struct RxDesc *desc = tp->RxDescArray + entry;
u32 status;
- status = le32_to_cpu(desc->opts1);
+ status = le32_to_cpu(READ_ONCE(desc->opts1));
if (status & DescOwn)
break;
--
2.42.0
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2023-11-06 13:03 ` [PATCH 5.4 07/74] r8169: fix the KCSAN reported data-race in rtl_tx while reading TxDescArray[entry].opts1 Greg Kroah-Hartman
2023-11-06 13:03 ` [PATCH 5.4 08/74] r8169: fix the KCSAN reported data race in rtl_rx while reading desc->opts1 Greg Kroah-Hartman
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