summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJinjian Song <jinjian.song@fibocom.com>2025-05-30 11:16:48 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-06-19 15:32:17 +0200
commite2df04e69c3f10b412f54be036dd0ed3b14756cf (patch)
tree7090c62128fb6651fbb093d90daabc6367d4c84c
parent4399f59a9467a324ed46657555f0e1f209a14acb (diff)
net: wwan: t7xx: Fix napi rx poll issue
[ Upstream commit 905fe0845bb27e4eed2ca27ea06e6c4847f1b2b1 ] When driver handles the napi rx polling requests, the netdev might have been released by the dellink logic triggered by the disconnect operation on user plane. However, in the logic of processing skb in polling, an invalid netdev is still being used, which causes a panic. BUG: kernel NULL pointer dereference, address: 00000000000000f1 Oops: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:dev_gro_receive+0x3a/0x620 [...] Call Trace: <IRQ> ? __die_body+0x68/0xb0 ? page_fault_oops+0x379/0x3e0 ? exc_page_fault+0x4f/0xa0 ? asm_exc_page_fault+0x22/0x30 ? __pfx_t7xx_ccmni_recv_skb+0x10/0x10 [mtk_t7xx (HASH:1400 7)] ? dev_gro_receive+0x3a/0x620 napi_gro_receive+0xad/0x170 t7xx_ccmni_recv_skb+0x48/0x70 [mtk_t7xx (HASH:1400 7)] t7xx_dpmaif_napi_rx_poll+0x590/0x800 [mtk_t7xx (HASH:1400 7)] net_rx_action+0x103/0x470 irq_exit_rcu+0x13a/0x310 sysvec_apic_timer_interrupt+0x56/0x90 </IRQ> Fixes: 5545b7b9f294 ("net: wwan: t7xx: Add NAPI support") Signed-off-by: Jinjian Song <jinjian.song@fibocom.com> Link: https://patch.msgid.link/20250530031648.5592-1-jinjian.song@fibocom.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/net/wwan/t7xx/t7xx_netdev.c11
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/net/wwan/t7xx/t7xx_netdev.c b/drivers/net/wwan/t7xx/t7xx_netdev.c
index 91fa082e9cab..fc0a7cb181df 100644
--- a/drivers/net/wwan/t7xx/t7xx_netdev.c
+++ b/drivers/net/wwan/t7xx/t7xx_netdev.c
@@ -302,7 +302,7 @@ static int t7xx_ccmni_wwan_newlink(void *ctxt, struct net_device *dev, u32 if_id
ccmni->ctlb = ctlb;
ccmni->dev = dev;
atomic_set(&ccmni->usage, 0);
- ctlb->ccmni_inst[if_id] = ccmni;
+ WRITE_ONCE(ctlb->ccmni_inst[if_id], ccmni);
ret = register_netdevice(dev);
if (ret)
@@ -324,6 +324,7 @@ static void t7xx_ccmni_wwan_dellink(void *ctxt, struct net_device *dev, struct l
if (WARN_ON(ctlb->ccmni_inst[if_id] != ccmni))
return;
+ WRITE_ONCE(ctlb->ccmni_inst[if_id], NULL);
unregister_netdevice(dev);
}
@@ -419,7 +420,7 @@ static void t7xx_ccmni_recv_skb(struct t7xx_ccmni_ctrl *ccmni_ctlb, struct sk_bu
skb_cb = T7XX_SKB_CB(skb);
netif_id = skb_cb->netif_idx;
- ccmni = ccmni_ctlb->ccmni_inst[netif_id];
+ ccmni = READ_ONCE(ccmni_ctlb->ccmni_inst[netif_id]);
if (!ccmni) {
dev_kfree_skb(skb);
return;
@@ -441,7 +442,7 @@ static void t7xx_ccmni_recv_skb(struct t7xx_ccmni_ctrl *ccmni_ctlb, struct sk_bu
static void t7xx_ccmni_queue_tx_irq_notify(struct t7xx_ccmni_ctrl *ctlb, int qno)
{
- struct t7xx_ccmni *ccmni = ctlb->ccmni_inst[0];
+ struct t7xx_ccmni *ccmni = READ_ONCE(ctlb->ccmni_inst[0]);
struct netdev_queue *net_queue;
if (netif_running(ccmni->dev) && atomic_read(&ccmni->usage) > 0) {
@@ -453,7 +454,7 @@ static void t7xx_ccmni_queue_tx_irq_notify(struct t7xx_ccmni_ctrl *ctlb, int qno
static void t7xx_ccmni_queue_tx_full_notify(struct t7xx_ccmni_ctrl *ctlb, int qno)
{
- struct t7xx_ccmni *ccmni = ctlb->ccmni_inst[0];
+ struct t7xx_ccmni *ccmni = READ_ONCE(ctlb->ccmni_inst[0]);
struct netdev_queue *net_queue;
if (atomic_read(&ccmni->usage) > 0) {
@@ -471,7 +472,7 @@ static void t7xx_ccmni_queue_state_notify(struct t7xx_pci_dev *t7xx_dev,
if (ctlb->md_sta != MD_STATE_READY)
return;
- if (!ctlb->ccmni_inst[0]) {
+ if (!READ_ONCE(ctlb->ccmni_inst[0])) {
dev_warn(&t7xx_dev->pdev->dev, "No netdev registered yet\n");
return;
}