[PATCH 5.14 473/849] mt76: connac: fix possible NULL pointer dereference in mt76_connac_get_phy_mode_v2

Greg Kroah-Hartman
2021-11-15T23:02:43Z

From: Lorenzo Bianconi <lorenzo@kernel.org>

[ Upstream commit b5f2ba8a4c794e8349c0e30036352b9f685164c4 ]

Fix the following NULL pointer dereference in mt76_connac_get_phy_mode_v2
routine triggered on mt7663s device when sta is NULL

[ 5.490700] mt7663s mmc0:0001:1: N9 Firmware Version: 3.1.1, Build Time: 20200604161656
[ 5.490815] mt7663s mmc0:0001:1: Region number: 0x4
[ 5.490868] mt7663s mmc0:0001:1: Parsing tailer Region: 0
[ 5.496251] mt7663s mmc0:0001:1: Region 0, override_addr = 0x00118000
[ 5.496419] mt7663s mmc0:0001:1: Parsing tailer Region: 1
[ 5.624027] mt7663s mmc0:0001:1: Parsing tailer Region: 2
[ 5.656999] mt7663s mmc0:0001:1: Parsing tailer Region: 3
[ 5.671876] mt7663s mmc0:0001:1: override_addr = 0x00118000, option = 3
[ 9.358658] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 9.358775] #PF: supervisor read access in kernel mode
[ 9.358831] #PF: error_code(0x0000) - not-present page
[ 9.358886] PGD 0 P4D 0
[ 9.358917] Oops: 0000 [#1] SMP
[ 9.358960] CPU: 0 PID: 235 Comm: NetworkManager Not tainted 5.15.0-rc4-kvm-02151-g39e333d657f4-dirty #769
[ 9.359057] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-4.fc34 04/01/2014
[ 9.359150] RIP: 0010:mt76_connac_get_phy_mode_v2+0xc9/0x11c
[ 9.359473] RAX: 0000000000000013 RBX: 0000000000000000 RCX: 0000000000000027
[ 9.359546] RDX: ffff8881f9c17358 RSI: 0000000000000001 RDI: ffff8881f9c17350
[ 9.359624] RBP: ffff88810bac1ed4 R08: ffffffff822a4a48 R09: 0000000000000003
[ 9.359697] R10: ffffffff82234a60 R11: ffffffff82234a60 R12: ffff88810bac1eec
[ 9.359779] R13: 0000000000000000 R14: ffff88810bad1648 R15: ffff88810bac1eb8
[ 9.359859] FS: 00007f5f1e45bbc0(0000) GS:ffff8881f9c00000(0000) knlGS:0000000000000000
[ 9.359939] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9.360003] CR2: 0000000000000000 CR3: 0000000105d5d000 CR4: 00000000000006b0
[ 9.360083] Call Trace:
[ 9.360116] mt76_connac_mcu_uni_add_bss.cold+0x21/0x250
[ 9.360175] ? schedule_preempt_disabled+0xa/0x10
[ 9.360232] ? __mutex_lock.constprop.0+0x2ab/0x460
[ 9.360286] mt7615_remove_interface+0x63/0x1d0
[ 9.360342] drv_remove_interface+0x32/0xe0
[ 9.360385] ieee80211_do_stop+0x5da/0x800
[ 9.360428] ? dev_reset_queue+0x30/0x90
[ 9.360472] ieee80211_stop+0x3b/0xb0
[ 9.360516] __dev_close_many+0x7a/0xd0
[ 9.360559] __dev_change_flags+0xd6/0x1f0
[ 9.360604] dev_change_flags+0x21/0x60
[ 9.360648] do_setlink+0x259/0xfb0
[ 9.360686] ? __nla_validate_parse+0x51/0xb80
[ 9.360742] __rtnl_newlink+0x5b3/0x960
[ 9.360785] ? inet6_fill_ifla6_attrs+0x41d/0x470
[ 9.360841] ? __kmalloc_track_caller+0x57/0x3c0
[ 9.360905] ? netlink_trim+0x8a/0xb0
[ 9.360949] ? skb_queue_tail+0x1b/0x50

Fixes: 67aa27431c7f8 ("mt76: mt7921: rely on mt76_connac_mcu common library")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
index 98d233e24afcc..d25b50e769328 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c
@@ -689,7 +689,7 @@ mt76_connac_get_phy_mode_v2(struct mt76_phy *mphy, struct ieee80211_vif *vif,
if (ht_cap->ht_supported)
mode |= PHY_TYPE_BIT_HT;

- if (he_cap->has_he)
+ if (he_cap && he_cap->has_he)
mode |= PHY_TYPE_BIT_HE;
} else if (band == NL80211_BAND_5GHZ) {
mode |= PHY_TYPE_BIT_OFDM;
@@ -700,7 +700,7 @@ mt76_connac_get_phy_mode_v2(struct mt76_phy *mphy, struct ieee80211_vif *vif,
if (vht_cap->vht_supported)
mode |= PHY_TYPE_BIT_VHT;

- if (he_cap->has_he)
+ if (he_cap && he_cap->has_he)
mode |= PHY_TYPE_BIT_HE;
}

--
2.33.0