[PATCH net] net/sched: Add xmit_recursion level in sch_direct_xmit()
From: Yue Haibing
Date: Fri May 24 2024 - 04:50:10 EST
packet from PF_PACKET socket ontop of an IPv6-backed ipvlan device will hit
WARN_ON_ONCE() in sk_mc_loop() through sch_direct_xmit() path while ipvlan
device has qdisc queue.
WARNING: CPU: 2 PID: 0 at net/core/sock.c:775 sk_mc_loop+0x2d/0x70
Modules linked in: sch_netem ipvlan rfkill cirrus drm_shmem_helper sg drm_kms_helper
CPU: 2 PID: 0 Comm: swapper/2 Kdump: loaded Not tainted 6.9.0+ #279
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:sk_mc_loop+0x2d/0x70
Code: fa 0f 1f 44 00 00 65 0f b7 15 f7 96 a3 4f 31 c0 66 85 d2 75 26 48 85 ff 74 1c
RSP: 0018:ffffa9584015cd78 EFLAGS: 00010212
RAX: 0000000000000011 RBX: ffff91e585793e00 RCX: 0000000002c6a001
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff91e589c0f000
RBP: ffff91e5855bd100 R08: 0000000000000000 R09: 3d00545216f43d00
R10: ffff91e584fdcc50 R11: 00000060dd8616f4 R12: ffff91e58132d000
R13: ffff91e584fdcc68 R14: ffff91e5869ce800 R15: ffff91e589c0f000
FS: 0000000000000000(0000) GS:ffff91e898100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f788f7c44c0 CR3: 0000000008e1a000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
? __warn+0x83/0x130
? sk_mc_loop+0x2d/0x70
? report_bug+0x18e/0x1a0
? handle_bug+0x3c/0x70
? exc_invalid_op+0x18/0x70
? asm_exc_invalid_op+0x1a/0x20
? sk_mc_loop+0x2d/0x70
ip6_finish_output2+0x31e/0x590
? nf_hook_slow+0x43/0xf0
ip6_finish_output+0x1f8/0x320
? __pfx_ip6_finish_output+0x10/0x10
ipvlan_xmit_mode_l3+0x22a/0x2a0 [ipvlan]
ipvlan_start_xmit+0x17/0x50 [ipvlan]
dev_hard_start_xmit+0x8c/0x1d0
sch_direct_xmit+0xa2/0x390
__qdisc_run+0x66/0xd0
net_tx_action+0x1ca/0x270
handle_softirqs+0xd6/0x2b0
__irq_exit_rcu+0x9b/0xc0
sysvec_apic_timer_interrupt+0x75/0x90
</IRQ>
Fixes: f60e5990d9c1 ("ipv6: protect skb->sk accesses from recursive dereference inside the stack")
Signed-off-by: Yue Haibing <yuehaibing@xxxxxxxxxx>
---
include/linux/netdevice.h | 17 +++++++++++++++++
net/core/dev.h | 17 -----------------
net/sched/sch_generic.c | 8 +++++---
3 files changed, 22 insertions(+), 20 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d20c6c99eb88..7c0c9e9b045e 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3261,6 +3261,23 @@ static inline int dev_recursion_level(void)
return this_cpu_read(softnet_data.xmit.recursion);
}
+#define XMIT_RECURSION_LIMIT 8
+static inline bool dev_xmit_recursion(void)
+{
+ return unlikely(__this_cpu_read(softnet_data.xmit.recursion) >
+ XMIT_RECURSION_LIMIT);
+}
+
+static inline void dev_xmit_recursion_inc(void)
+{
+ __this_cpu_inc(softnet_data.xmit.recursion);
+}
+
+static inline void dev_xmit_recursion_dec(void)
+{
+ __this_cpu_dec(softnet_data.xmit.recursion);
+}
+
void __netif_schedule(struct Qdisc *q);
void netif_schedule_queue(struct netdev_queue *txq);
diff --git a/net/core/dev.h b/net/core/dev.h
index b7b518bc2be5..49345ad7350b 100644
--- a/net/core/dev.h
+++ b/net/core/dev.h
@@ -149,21 +149,4 @@ static inline void xdp_do_check_flushed(struct napi_struct *napi) { }
struct napi_struct *napi_by_id(unsigned int napi_id);
void kick_defer_list_purge(struct softnet_data *sd, unsigned int cpu);
-#define XMIT_RECURSION_LIMIT 8
-static inline bool dev_xmit_recursion(void)
-{
- return unlikely(__this_cpu_read(softnet_data.xmit.recursion) >
- XMIT_RECURSION_LIMIT);
-}
-
-static inline void dev_xmit_recursion_inc(void)
-{
- __this_cpu_inc(softnet_data.xmit.recursion);
-}
-
-static inline void dev_xmit_recursion_dec(void)
-{
- __this_cpu_dec(softnet_data.xmit.recursion);
-}
-
#endif
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 2a637a17061b..74d9b43b7767 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -339,11 +339,13 @@ bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
if (likely(skb)) {
HARD_TX_LOCK(dev, txq, smp_processor_id());
- if (!netif_xmit_frozen_or_stopped(txq))
+ if (!netif_xmit_frozen_or_stopped(txq)) {
+ dev_xmit_recursion_inc();
skb = dev_hard_start_xmit(skb, dev, txq, &ret);
- else
+ dev_xmit_recursion_dec();
+ } else {
qdisc_maybe_clear_missed(q, txq);
-
+ }
HARD_TX_UNLOCK(dev, txq);
} else {
if (root_lock)
--
2.34.1