wifi: mt76: usb: fix use-after-free in mt76u_free_rx_queue

Fix the following use-after-free issue in mt76u_free_rx_queue routine:

usb 3-3.3.4: reset high-speed USB device number 8 using xhci_hcd
iwlwifi 0000:05:00.0: Detected RF HR B3, rfid=0x10a100
iwlwifi 0000:05:00.0: base HW address: 50:eb:71:79:02:57
iwlwifi 0000:05:00.0 wlp5s0: renamed from wlan0
mt76x2u 3-3.3.4:1.0: ASIC revision: 76320044
usb 3-3.3.1: 1:3 : unsupported format bits 0x100000000
mt76x2u 3-3.3.4:1.0: could not get hardware semaphore for ROM PATCH
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 13 PID: 983 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110
Modules linked in: snd_seq_midi snd_seq_midi_event mt76x2u(+)
mt76x2_common mt76x02_usb mt76_usb iwlmvm mt76x02_lib mt76
snd_hda_codec_realtek intel_rapl_msr snd_hda_codec_generic
snd_hda_codec_hdmi intel_rapl_common snd_hda_intel mac80211
snd_intel_dspcfg snd_usb_audio(+) snd_intel_sdw_acpi btusb
edac_mce_amd snd_hda_codec btrtl btbcm snd_usbmidi_lib snd_hda_core
btintel snd_rawmidi btmtk snd_hwdep libarc4 mc iwlwifi kvm_amd snd_seq
vfat bluetooth eeepc_wmi asus_ec_sensors snd_seq_device fat kvm
cfg80211 asus_wmi snd_pcm irqbypass ledtrig_audio sparse_keymap rapl
wmi_bmof platform_profile xpad snd_timer k10temp ff_memless i2c_piix4
rfkill snd joydev soundcore acpi_cpufreq loop zram amdgpu
crct10dif_pclmul crc32_pclmul crc32c_intel polyval_clmulni
polyval_generic drm_ttm_helper ttm video iommu_v2 ucsi_ccg drm_buddy
gpu_sched typec_ucsi ghash_clmulni_intel drm_display_helper igb
sha512_ssse3 typec ccp nvme cec sp5100_tco nvme_core dca nvme_common
wmi ip6_tables ip_tables fuse
BTRFS info (device nvme1n1): enabling ssd optimizations
CPU: 13 PID: 983 Comm: (udev-worker) Tainted: G        W    L
-------  ---  6.3.0-0.rc0.20230222git5b7c4cabbb65.3.fc39.x86_64+debug
BTRFS info (device nvme1n1): auto enabling async discard
Hardware name: System manufacturer System Product Name/ROG STRIX
X570-I GAMING, BIOS 4601 02/02/2023
RIP: 0010:refcount_warn_saturate+0xba/0x110
Code: 01 01 e8 69 a6 83 ff 0f 0b e9 52 f4 85 00 80 3d 69 6f ec 01 00
75 85 48 c7 c7 d0 25 b3 a9 c6 05 59 6f ec 01 01 e8 46 a6 83 ff <0f> 0b
e9 2f f4 85 00 80 3d 47 6f ec 01 00 0f 85 5e ff ff ff 48 c7
RSP: 0018:ffffb4010456fb78 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000080000000 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffffffffa9b17e3e RDI: 00000000ffffffff
RBP: ffff8d15877336c0 R08: 0000000000000000 R09: ffffb4010456fa00
R10: 0000000000000003 R11: ffff8d246e2fffe8 R12: 0000000000000080
R13: ffff8d15b42fd000 R14: 0000000000000000 R15: ffff8d1587736a58
FS:  00007fc05ae34940(0000) GS:ffff8d2425e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d801f1d540 CR3: 000000011df60000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 mt76u_queues_deinit+0x2a0/0x370 [mt76_usb]
 mt76x2u_probe+0xf3/0x130 [mt76x2u]
 usb_probe_interface+0xe8/0x300
 really_probe+0x1b6/0x410
 __driver_probe_device+0x78/0x170
 driver_probe_device+0x1f/0x90
 __driver_attach+0xd2/0x1c0
 ? __pfx___driver_attach+0x10/0x10
 bus_for_each_dev+0x8a/0xd0
 bus_add_driver+0x141/0x230
 driver_register+0x77/0x120
 usb_register_driver+0xaf/0x170
 ? __pfx_init_module+0x10/0x10 [mt76x2u]
 do_one_initcall+0x6e/0x350
 do_init_module+0x4a/0x220
 __do_sys_init_module+0x192/0x1c0
 ? lock_is_held_type+0xce/0x120
 do_syscall_64+0x5b/0x80
 ? lock_is_held_type+0xce/0x120
 ? asm_exc_page_fault+0x22/0x30
 ? lockdep_hardirqs_on+0x7d/0x100
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fc05b1351be
Code: 48 8b 0d 4d 0c 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00 00 0f 05 <48> 3d
01 f0 ff ff 73 01 c3 48 8b 0d 1a 0c 0c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffd947c0988 EFLAGS: 00000246 ORIG_RAX: 00000000000000af
RAX: ffffffffffffffda RBX: 000055d801f2b090 RCX: 00007fc05b1351be
RDX: 00007fc05b65c07d RSI: 00000000000234be RDI: 000055d802c6b170
RBP: 00007ffd947c0a40 R08: 000055d8019b4690 R09: 0000000000022000
R10: 000000055d8019b4 R11: 0000000000000246 R12: 00007fc05b65c07d
R13: 0000000000020000 R14: 000055d801f39770 R15: 000055d801f47780
 </TASK>
irq event stamp: 186313
hardirqs last  enabled at (186323): [<ffffffffa81c675e>]
__up_console_sem+0x5e/0x70
hardirqs last disabled at (186332): [<ffffffffa81c6743>]
__up_console_sem+0x43/0x70
softirqs last  enabled at (186022): [<ffffffffa811d2f7>]
__irq_exit_rcu+0xd7/0x160
softirqs last disabled at (186017): [<ffffffffa811d2f7>]
__irq_exit_rcu+0xd7/0x160
---[ end trace 0000000000000000 ]---
mt76x2u: probe of 3-3.3.4:1.0 failed with error -110
usbcore: registered new interface driver mt76x2u
kauditd_printk_skb: 32 callbacks suppressed

Fixes: 2f5c3c77fc ("wifi: mt76: switch to page_pool allocator")
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/f2398f68011c976510c81e1964975b677e65860e.1677193208.git.lorenzo@kernel.org

drivers/net/wireless/mediatek/mt76/usb.c

@@ -706,6 +706,7 @@ mt76u_free_rx_queue(struct mt76_dev *dev, struct mt76_queue *q)
 		q->entry[i].urb = NULL;
 	}
 	page_pool_destroy(q->page_pool);
+	q->page_pool = NULL;
 }
 
 static void mt76u_free_rx(struct mt76_dev *dev)