ath10k: Fix NULL pointer dereference in AHB device probe

This fixes a NULL pointer dereference in the probe path for AHB devices.
There attr parameter in the ath10k_ce_alloc_pipe() function is not
initialized, but accessed. This function is called by
ath10k_pci_setup_resource() which is called by ath10k_ahb_probe().

The struct ath10k_pci is also used for AHB devices and not only for PCI
devices.

The initialization of the new members of struct ath10k_pci is moved to
ath10k_pci_setup_resource() which is used by the PCI and the AHB code.

This also fixes a use after free bug in ath10k_pci_remove() when ar_pci
is accessed after ath10k_core_destroy() was called, which calls
ieee80211_free_hw() and frees this memory.

This fixes the following bug seen with backports-5.8-rc2 on OpenWrt on a
IPQ4019 device:

[   11.117462] 8<--- cut here ---
[   11.117494] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   11.119510] pgd = f377fd58
[   11.127657] [00000000] *pgd=8e9a0835, *pte=00000000, *ppte=00000000
[   11.130206] Internal error: Oops: 17 [#1] SMP ARM
[   11.136339] Modules linked in: ath10k_pci(+) ath10k_core ath xt_state xt_nat xt_conntrack xt_REDIRECT xt_MASQUERADE xt_FLOWOFFLOAD pppox ppp_generic nf_nat nf_flow_table_hw nf_flow_table nf_conntrack_rtcache nf_conntrack mac80211 ipt_REJECT cfg80211 xt_time xt_tcpudp xt_multiport xt_mark xt_mac xt_limit xt_comment xt_TCPMSS xt_LOG slhc nf_reject_ipv4 nf_log_ipv4 nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_filter ip_tables crc_ccitt compat nf_log_ipv6 nf_log_common ip6table_mangle ip6table_filter ip6_tables ip6t_REJECT x_tables nf_reject_ipv6 leds_gpio xhci_plat_hcd xhci_pci xhci_hcd dwc3 dwc3_qcom gpio_button_hotplug
[   11.174355] CPU: 2 PID: 257 Comm: kmodloader Not tainted 5.4.51 #0
[   11.196585] Hardware name: Generic DT based system
[   11.202746] PC is at ath10k_ce_alloc_pipe+0x58/0x180 [ath10k_core]
[   11.207459] LR is at ath10k_pci_alloc_pipes+0x94/0xc8 [ath10k_pci]
[   11.213600] pc : [<bf2c96cc>]    lr : [<bf2fbf98>]    psr: 80000013
[   11.219760] sp : cea0dc90  ip : cf4001f0  fp : 00000001
[   11.225923] r10: 00000000  r9 : 00000018  r8 : ce4963b4
[   11.231133] r7 : 00000000  r6 : ce491ea0  r5 : 00000000  r4 : ce4963b4
[   11.236342] r3 : 0004a000  r2 : 0004a000  r1 : bf2d0d70  r0 : 00000006
[   11.242942] Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[   11.249452] Control: 10c5387d  Table: 8e9c006a  DAC: 00000051
[   11.256656] Process kmodloader (pid: 257, stack limit = 0xaba286ca)
[   11.262386] Stack: (0xcea0dc90 to 0xcea0e000)
[   11.268462] dc80:                                     00000000 ce49629c ce491ea0 ce4963bc
[   11.272984] dca0: ce495ea0 bf2fbf98 00000002 ce4963a8 ce495ea0 00000000 ce491ea0 cf95d800
[   11.281142] dcc0: cf95d810 cf95d810 00000001 bf2fc854 00000000 cf95d800 bf300748 ce495ea0
[   11.289304] dce0: ce491ea0 d1300000 cf95d800 bf2fde8c 00000000 00000001 ce49cea0 00000000
[   11.297462] dd00: 00000000 00000000 bf3010a0 cf95d810 bf3010a0 c0b61580 00000000 00000000
[   11.305624] dd20: bf3010a0 0000000b c0b04e48 c06110c8 c0b61588 cf95d810 c0b61580 c060f740
[   11.313781] dd40: cf95d810 00000000 bf3010a0 00000000 00000000 ce49d2a4 bf301100 c060fc90
[   11.321943] dd60: 00000000 bf3010a0 cf95d810 c060fcf0 cf95d810 bf3010a0 c060fc98 c060dca4
[   11.330101] dd80: cf809d58 cf952cb4 bf3010a0 ce967900 c0b1f2c8 c060ec28 bf3007b8 bf301038
[   11.338263] dda0: bf3010a0 bf3010a0 c0b2d4d4 ffffe000 bf304000 c0610278 c0b04e48 c0b2d4d4
[   11.346422] ddc0: ffffe000 bf2fe2b4 c0b04e48 bf30403c c0b04e48 c0302764 8040003f 00000001
[   11.354582] dde0: 38e38e39 ce513580 c0b2cb50 cf801e00 cffbc6ac ce513600 cf801e00 cffbc6ac
[   11.362740] de00: 8040003e ce49d280 00000001 c0428d54 00000001 cf801e00 cffbc6ac ce513580
[   11.370900] de20: ce49d280 0e391998 bf301100 ce49d340 d12d2000 ce49d280 00000001 c0398c2c
[   11.379061] de40: 00000001 cea0df34 cea0df34 00000001 d12d2000 c039ae48 bf30110c 00007fff
[   11.387221] de60: bf301100 c0398044 cf804028 bf301148 c0397674 bf30126c c08ee5c0 c08ee70c
[   11.395380] de80: bf30110c c0b04e48 c08ee518 00000000 c08ee570 c0b04e48 ce513600 fffff000
[   11.403540] dea0: 00000001 ce513580 0000000d 0000000d 00000000 00000000 00000000 00000000
[   11.411698] dec0: 00000000 00000000 6e72656b 00006c65 00000000 00000000 00000000 00000000
[   11.419858] dee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   11.428018] df00: 00000000 0e391998 00000000 0000c610 d12de610 00000000 0062c620 ffffe000
[   11.436180] df20: 000129d1 00000051 00000000 c039b228 00000000 d12d7afd d12d8e80 d12d2000
[   11.444337] df40: 0000c610 d12de0e8 d12ddfa8 d12dab74 00009000 00009570 00003a2c 00009cae
[   11.452498] df60: 00000000 00000000 00000000 00003a1c 0000001e 0000001f 00000018 00000000
[   11.460656] df80: 00000010 00000000 00000000 00000000 00000003 00000080 c0301204 cea0c000
[   11.468817] dfa0: 00000080 c0301000 00000000 00000000 00620010 0000c610 000129d1 00000014
[   11.476975] dfc0: 00000000 00000000 00000003 00000080 0000c610 00000000 b6fc1d20 00000000
[   11.485137] dfe0: bef0ad14 bef0acf8 00011e14 b6f74c94 60000010 00620010 00000000 00000000
[   11.493390] [<bf2c96cc>] (ath10k_ce_alloc_pipe [ath10k_core]) from [<bf2fbf98>] (ath10k_pci_alloc_pipes+0x94/0xc8 [ath10k_pci])
[   11.501498] [<bf2fbf98>] (ath10k_pci_alloc_pipes [ath10k_pci]) from [<bf2fc854>] (ath10k_pci_setup_resource+0xb8/0xf0 [ath10k_pci])
[   11.512773] [<bf2fc854>] (ath10k_pci_setup_resource [ath10k_pci]) from [<bf2fde8c>] (ath10k_ahb_probe+0x32c/0x670 [ath10k_pci])
[   11.524566] [<bf2fde8c>] (ath10k_ahb_probe [ath10k_pci]) from [<c06110c8>] (platform_drv_probe+0x34/0x70)
[   11.536016] [<c06110c8>] (platform_drv_probe) from [<c060f740>] (really_probe+0x1f0/0x358)
[   11.545729] [<c060f740>] (really_probe) from [<c060fc90>] (device_driver_attach+0x58/0x60)
[   11.553886] [<c060fc90>] (device_driver_attach) from [<c060fcf0>] (__driver_attach+0x58/0xcc)
[   11.562134] [<c060fcf0>] (__driver_attach) from [<c060dca4>] (bus_for_each_dev+0x68/0x8c)
[   11.570731] [<c060dca4>] (bus_for_each_dev) from [<c060ec28>] (bus_add_driver+0x1c8/0x1d8)
[   11.578886] [<c060ec28>] (bus_add_driver) from [<c0610278>] (driver_register+0x74/0x108)
[   11.587060] [<c0610278>] (driver_register) from [<bf2fe2b4>] (ath10k_ahb_init+0x18/0x38 [ath10k_pci])
[   11.595320] [<bf2fe2b4>] (ath10k_ahb_init [ath10k_pci]) from [<bf30403c>] (init_module+0x3c/0x1000 [ath10k_pci])
[   11.604432] [<bf30403c>] (init_module [ath10k_pci]) from [<c0302764>] (do_one_initcall+0x84/0x1d8)
[   11.614657] [<c0302764>] (do_one_initcall) from [<c0398c2c>] (do_init_module+0x5c/0x228)
[   11.623421] [<c0398c2c>] (do_init_module) from [<c039ae48>] (load_module+0x1fc8/0x224c)
[   11.631663] [<c039ae48>] (load_module) from [<c039b228>] (sys_init_module+0x15c/0x17c)
[   11.639390] [<c039b228>] (sys_init_module) from [<c0301000>] (ret_fast_syscall+0x0/0x54)
[   11.647370] Exception stack(0xcea0dfa8 to 0xcea0dff0)
[   11.655615] dfa0:                   00000000 00000000 00620010 0000c610 000129d1 00000014
[   11.660569] dfc0: 00000000 00000000 00000003 00000080 0000c610 00000000 b6fc1d20 00000000
[   11.668725] dfe0: bef0ad14 bef0acf8 00011e14 b6f74c94
[   11.676886] Code: e1c321d4 e0433002 e0232397 e5843014 (e5953000)
[   11.681958] ---[ end trace 8f35917de2e76854 ]---

Fixes: 521fc37b ("ath10k: Avoid override CE5 configuration for QCA99X0 chipsets")
Reported-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> [ipq40xx/ map-ac2200]
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200714205802.17688-1-hauke@hauke-m.de

drivers/net/wireless/ath/ath10k/ahb.c

@@ -820,7 +820,7 @@ static int ath10k_ahb_probe(struct platform_device *pdev)
 	ath10k_ahb_release_irq_legacy(ar);
 
 err_free_pipes:
-	ath10k_pci_free_pipes(ar);
+	ath10k_pci_release_resource(ar);
 
 err_resource_deinit:
 	ath10k_ahb_resource_deinit(ar);

drivers/net/wireless/ath/ath10k/pci.c

@@ -3473,6 +3473,28 @@ int ath10k_pci_setup_resource(struct ath10k *ar)
 
 	timer_setup(&ar_pci->rx_post_retry, ath10k_pci_rx_replenish_retry, 0);
 
+	ar_pci->attr = kmemdup(pci_host_ce_config_wlan,
+			       sizeof(pci_host_ce_config_wlan),
+			       GFP_KERNEL);
+	if (!ar_pci->attr)
+		return -ENOMEM;
+
+	ar_pci->pipe_config = kmemdup(pci_target_ce_config_wlan,
+				      sizeof(pci_target_ce_config_wlan),
+				      GFP_KERNEL);
+	if (!ar_pci->pipe_config) {
+		ret = -ENOMEM;
+		goto err_free_attr;
+	}
+
+	ar_pci->serv_to_pipe = kmemdup(pci_target_service_to_ce_map_wlan,
+				       sizeof(pci_target_service_to_ce_map_wlan),
+				       GFP_KERNEL);
+	if (!ar_pci->serv_to_pipe) {
+		ret = -ENOMEM;
+		goto err_free_pipe_config;
+	}
+
 	if (QCA_REV_6174(ar) || QCA_REV_9377(ar))
 		ath10k_pci_override_ce_config(ar);
 
@@ -3480,18 +3502,31 @@ int ath10k_pci_setup_resource(struct ath10k *ar)
 	if (ret) {
 		ath10k_err(ar, "failed to allocate copy engine pipes: %d\n",
 			   ret);
-		return ret;
+		goto err_free_serv_to_pipe;
 	}
 
 	return 0;
+
+err_free_serv_to_pipe:
+	kfree(ar_pci->serv_to_pipe);
+err_free_pipe_config:
+	kfree(ar_pci->pipe_config);
+err_free_attr:
+	kfree(ar_pci->attr);
+	return ret;
 }
 
 void ath10k_pci_release_resource(struct ath10k *ar)
 {
+	struct ath10k_pci *ar_pci = ath10k_pci_priv(ar);
+
 	ath10k_pci_rx_retry_sync(ar);
 	netif_napi_del(&ar->napi);
 	ath10k_pci_ce_deinit(ar);
 	ath10k_pci_free_pipes(ar);
+	kfree(ar_pci->attr);
+	kfree(ar_pci->pipe_config);
+	kfree(ar_pci->serv_to_pipe);
 }
 
 static const struct ath10k_bus_ops ath10k_pci_bus_ops = {
@@ -3601,30 +3636,6 @@ static int ath10k_pci_probe(struct pci_dev *pdev,
 
 	timer_setup(&ar_pci->ps_timer, ath10k_pci_ps_timer, 0);
 
-	ar_pci->attr = kmemdup(pci_host_ce_config_wlan,
-			       sizeof(pci_host_ce_config_wlan),
-			       GFP_KERNEL);
-	if (!ar_pci->attr) {
-		ret = -ENOMEM;
-		goto err_free;
-	}
-
-	ar_pci->pipe_config = kmemdup(pci_target_ce_config_wlan,
-				      sizeof(pci_target_ce_config_wlan),
-				      GFP_KERNEL);
-	if (!ar_pci->pipe_config) {
-		ret = -ENOMEM;
-		goto err_free;
-	}
-
-	ar_pci->serv_to_pipe = kmemdup(pci_target_service_to_ce_map_wlan,
-				       sizeof(pci_target_service_to_ce_map_wlan),
-				       GFP_KERNEL);
-	if (!ar_pci->serv_to_pipe) {
-		ret = -ENOMEM;
-		goto err_free;
-	}
-
 	ret = ath10k_pci_setup_resource(ar);
 	if (ret) {
 		ath10k_err(ar, "failed to setup resource: %d\n", ret);
@@ -3705,10 +3716,9 @@ static int ath10k_pci_probe(struct pci_dev *pdev,
 
 err_free_irq:
 	ath10k_pci_free_irq(ar);
-	ath10k_pci_rx_retry_sync(ar);
 
 err_deinit_irq:
-	ath10k_pci_deinit_irq(ar);
+	ath10k_pci_release_resource(ar);
 
 err_sleep:
 	ath10k_pci_sleep_sync(ar);
@@ -3720,29 +3730,18 @@ static int ath10k_pci_probe(struct pci_dev *pdev,
 err_core_destroy:
 	ath10k_core_destroy(ar);
 
-err_free:
-	kfree(ar_pci->attr);
-	kfree(ar_pci->pipe_config);
-	kfree(ar_pci->serv_to_pipe);
-
 	return ret;
 }
 
 static void ath10k_pci_remove(struct pci_dev *pdev)
 {
 	struct ath10k *ar = pci_get_drvdata(pdev);
-	struct ath10k_pci *ar_pci;
 
 	ath10k_dbg(ar, ATH10K_DBG_PCI, "pci remove\n");
 
 	if (!ar)
 		return;
 
-	ar_pci = ath10k_pci_priv(ar);
-
-	if (!ar_pci)
-		return;
-
 	ath10k_core_unregister(ar);
 	ath10k_pci_free_irq(ar);
 	ath10k_pci_deinit_irq(ar);
@@ -3750,9 +3749,6 @@ static void ath10k_pci_remove(struct pci_dev *pdev)
 	ath10k_pci_sleep_sync(ar);
 	ath10k_pci_release(ar);
 	ath10k_core_destroy(ar);
-	kfree(ar_pci->attr);
-	kfree(ar_pci->pipe_config);
-	kfree(ar_pci->serv_to_pipe);
 }
 
 MODULE_DEVICE_TABLE(pci, ath10k_pci_id_table);