[PATCH AUTOSEL 4.4 03/29] ar5523: Fix null-ptr-deref with unexpected WDCMSG_TARGET_START reply

[PATCH AUTOSEL 4.4 03/29] ar5523: Fix null-ptr-deref with unexpected WDCMSG_TARGET_START reply

[Sasha Levin]

From: Zekun Shen <bruceshenzk@gmail.com>

[ Upstream commit ae80b6033834342601e99f74f6a62ff5092b1cee ]

Unexpected WDCMSG_TARGET_START replay can lead to null-ptr-deref
when ar->tx_cmd->odata is NULL. The patch adds a null check to
prevent such case.

KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
 ar5523_cmd+0x46a/0x581 [ar5523]
 ar5523_probe.cold+0x1b7/0x18da [ar5523]
 ? ar5523_cmd_rx_cb+0x7a0/0x7a0 [ar5523]
 ? __pm_runtime_set_status+0x54a/0x8f0
 ? _raw_spin_trylock_bh+0x120/0x120
 ? pm_runtime_barrier+0x220/0x220
 ? __pm_runtime_resume+0xb1/0xf0
 usb_probe_interface+0x25b/0x710
 really_probe+0x209/0x5d0
 driver_probe_device+0xc6/0x1b0
 device_driver_attach+0xe2/0x120

I found the bug using a custome USBFuzz port. It's a research work
to fuzz USB stack/drivers. I modified it to fuzz ath9k driver only,
providing hand-crafted usb descriptors to QEMU.

After fixing the code (fourth byte in usb packet) to WDCMSG_TARGET_START,
I got the null-ptr-deref bug. I believe the bug is triggerable whenever
cmd->odata is NULL. After patching, I tested with the same input and no
longer see the KASAN report.

This was NOT tested on a real device.

Signed-off-by: Zekun Shen <bruceshenzk@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/YXsmPQ3awHFLuAj2@10-18-43-117.dynapool.wireless.nyu.edu
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/ath/ar5523/ar5523.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c
index bc6330b437958..67c20cb92f138 100644
--- a/drivers/net/wireless/ath/ar5523/ar5523.c
+++ b/drivers/net/wireless/ath/ar5523/ar5523.c
@@ -153,6 +153,10 @@ static void ar5523_cmd_rx_cb(struct urb *urb)
 			ar5523_err(ar, "Invalid reply to WDCMSG_TARGET_START");
 			return;
 		}
+		if (!cmd->odata) {
+			ar5523_err(ar, "Unexpected WDCMSG_TARGET_START reply");
+			return;
+		}
 		memcpy(cmd->odata, hdr + 1, sizeof(u32));
 		cmd->olen = sizeof(u32);
 		cmd->res = 0;
-- 
2.34.1

[PATCH AUTOSEL 4.4 08/29] mwifiex: Fix skb_over_panic in mwifiex_usb_recv()

[Sasha Levin]

From: Zekun Shen <bruceshenzk@gmail.com>

[ Upstream commit 04d80663f67ccef893061b49ec8a42ff7045ae84 ]

Currently, with an unknown recv_type, mwifiex_usb_recv
just return -1 without restoring the skb. Next time
mwifiex_usb_rx_complete is invoked with the same skb,
calling skb_put causes skb_over_panic.

The bug is triggerable with a compromised/malfunctioning
usb device. After applying the patch, skb_over_panic
no longer shows up with the same input.

Attached is the panic report from fuzzing.
skbuff: skb_over_panic: text:000000003bf1b5fa
 len:2048 put:4 head:00000000dd6a115b data:000000000a9445d8
 tail:0x844 end:0x840 dev:<NULL>
kernel BUG at net/core/skbuff.c:109!
invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 PID: 198 Comm: in:imklog Not tainted 5.6.0 #60
RIP: 0010:skb_panic+0x15f/0x161
Call Trace:
 <IRQ>
 ? mwifiex_usb_rx_complete+0x26b/0xfcd [mwifiex_usb]
 skb_put.cold+0x24/0x24
 mwifiex_usb_rx_complete+0x26b/0xfcd [mwifiex_usb]
 __usb_hcd_giveback_urb+0x1e4/0x380
 usb_giveback_urb_bh+0x241/0x4f0
 ? __hrtimer_run_queues+0x316/0x740
 ? __usb_hcd_giveback_urb+0x380/0x380
 tasklet_action_common.isra.0+0x135/0x330
 __do_softirq+0x18c/0x634
 irq_exit+0x114/0x140
 smp_apic_timer_interrupt+0xde/0x380
 apic_timer_interrupt+0xf/0x20
 </IRQ>

Reported-by: Brendan Dolan-Gavitt <brendandg@nyu.edu>
Signed-off-by: Zekun Shen <bruceshenzk@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/YX4CqjfRcTa6bVL+@Zekuns-MBP-16.fios-router.home
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/mwifiex/usb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/mwifiex/usb.c b/drivers/net/wireless/mwifiex/usb.c
index 1be7b219cb202..4cdf6450aeedd 100644
--- a/drivers/net/wireless/mwifiex/usb.c
+++ b/drivers/net/wireless/mwifiex/usb.c
@@ -132,7 +132,8 @@ static int mwifiex_usb_recv(struct mwifiex_adapter *adapter,
 		default:
 			mwifiex_dbg(adapter, ERROR,
 				    "unknown recv_type %#x\n", recv_type);
-			return -1;
+			ret = -1;
+			goto exit_restore_skb;
 		}
 		break;
 	case MWIFIEX_USB_EP_DATA:
-- 
2.34.1

[PATCH AUTOSEL 4.4 12/29] iwlwifi: mvm: synchronize with FW after multicast commands

[Sasha Levin]

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit db66abeea3aefed481391ecc564fb7b7fb31d742 ]

If userspace installs a lot of multicast groups very quickly, then
we may run out of command queue space as we send the updates in an
asynchronous fashion (due to locking concerns), and the CPU can
create them faster than the firmware can process them. This is true
even when mac80211 has a work struct that gets scheduled.

Fix this by synchronizing with the firmware after sending all those
commands - outside of the iteration we can send a synchronous echo
command that just has the effect of the CPU waiting for the prior
asynchronous commands to finish. This also will cause fewer of the
commands to be sent to the firmware overall, because the work will
only run once when rescheduled multiple times while it's running.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=213649
Suggested-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reported-by: Maximilian Ernestus <maximilian@ernestus.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211204083238.51aea5b79ea4.I88a44798efda16e9fe480fb3e94224931d311b29@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/iwlwifi/mvm/mac80211.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index ca498b1f1f568..6417fda88733c 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -1957,6 +1957,7 @@ static void iwl_mvm_recalc_multicast(struct iwl_mvm *mvm)
 	struct iwl_mvm_mc_iter_data iter_data = {
 		.mvm = mvm,
 	};
+	int ret;
 
 	lockdep_assert_held(&mvm->mutex);
 
@@ -1966,6 +1967,22 @@ static void iwl_mvm_recalc_multicast(struct iwl_mvm *mvm)
 	ieee80211_iterate_active_interfaces_atomic(
 		mvm->hw, IEEE80211_IFACE_ITER_NORMAL,
 		iwl_mvm_mc_iface_iterator, &iter_data);
+
+	/*
+	 * Send a (synchronous) ech command so that we wait for the
+	 * multiple asynchronous MCAST_FILTER_CMD commands sent by
+	 * the interface iterator. Otherwise, we might get here over
+	 * and over again (by userspace just sending a lot of these)
+	 * and the CPU can send them faster than the firmware can
+	 * process them.
+	 * Note that the CPU is still faster - but with this we'll
+	 * actually send fewer commands overall because the CPU will
+	 * not schedule the work in mac80211 as frequently if it's
+	 * still running when rescheduled (possibly multiple times).
+	 */
+	ret = iwl_mvm_send_cmd_pdu(mvm, ECHO_CMD, 0, 0, NULL);
+	if (ret)
+		IWL_ERR(mvm, "Failed to synchronize multicast groups update\n");
 }
 
 static u64 iwl_mvm_prepare_multicast(struct ieee80211_hw *hw,
-- 
2.34.1

[PATCH AUTOSEL 4.4 18/29] ath9k: Fix out-of-bound memcpy in ath9k_hif_usb_rx_stream

[Sasha Levin]

From: Zekun Shen <bruceshenzk@gmail.com>

[ Upstream commit 6ce708f54cc8d73beca213cec66ede5ce100a781 ]

Large pkt_len can lead to out-out-bound memcpy. Current
ath9k_hif_usb_rx_stream allows combining the content of two urb
inputs to one pkt. The first input can indicate the size of the
pkt. Any remaining size is saved in hif_dev->rx_remain_len.
While processing the next input, memcpy is used with rx_remain_len.

4-byte pkt_len can go up to 0xffff, while a single input is 0x4000
maximum in size (MAX_RX_BUF_SIZE). Thus, the patch adds a check for
pkt_len which must not exceed 2 * MAX_RX_BUG_SIZE.

BUG: KASAN: slab-out-of-bounds in ath9k_hif_usb_rx_cb+0x490/0xed7 [ath9k_htc]
Read of size 46393 at addr ffff888018798000 by task kworker/0:1/23

CPU: 0 PID: 23 Comm: kworker/0:1 Not tainted 5.6.0 #63
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
Workqueue: events request_firmware_work_func
Call Trace:
 <IRQ>
 dump_stack+0x76/0xa0
 print_address_description.constprop.0+0x16/0x200
 ? ath9k_hif_usb_rx_cb+0x490/0xed7 [ath9k_htc]
 ? ath9k_hif_usb_rx_cb+0x490/0xed7 [ath9k_htc]
 __kasan_report.cold+0x37/0x7c
 ? ath9k_hif_usb_rx_cb+0x490/0xed7 [ath9k_htc]
 kasan_report+0xe/0x20
 check_memory_region+0x15a/0x1d0
 memcpy+0x20/0x50
 ath9k_hif_usb_rx_cb+0x490/0xed7 [ath9k_htc]
 ? hif_usb_mgmt_cb+0x2d9/0x2d9 [ath9k_htc]
 ? _raw_spin_lock_irqsave+0x7b/0xd0
 ? _raw_spin_trylock_bh+0x120/0x120
 ? __usb_unanchor_urb+0x12f/0x210
 __usb_hcd_giveback_urb+0x1e4/0x380
 usb_giveback_urb_bh+0x241/0x4f0
 ? __hrtimer_run_queues+0x316/0x740
 ? __usb_hcd_giveback_urb+0x380/0x380
 tasklet_action_common.isra.0+0x135/0x330
 __do_softirq+0x18c/0x634
 irq_exit+0x114/0x140
 smp_apic_timer_interrupt+0xde/0x380
 apic_timer_interrupt+0xf/0x20

I found the bug using a custome USBFuzz port. It's a research work
to fuzz USB stack/drivers. I modified it to fuzz ath9k driver only,
providing hand-crafted usb descriptors to QEMU.

After fixing the value of pkt_tag to ATH_USB_RX_STREAM_MODE_TAG in QEMU
emulation, I found the KASAN report. The bug is triggerable whenever
pkt_len is above two MAX_RX_BUG_SIZE. I used the same input that crashes
to test the driver works when applying the patch.

Signed-off-by: Zekun Shen <bruceshenzk@gmail.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/YXsidrRuK6zBJicZ@10-18-43-117.dynapool.wireless.nyu.edu
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/ath/ath9k/hif_usb.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/wireless/ath/ath9k/hif_usb.c b/drivers/net/wireless/ath/ath9k/hif_usb.c
index 75072a8f8cf42..15fb14f818f8b 100644
--- a/drivers/net/wireless/ath/ath9k/hif_usb.c
+++ b/drivers/net/wireless/ath/ath9k/hif_usb.c
@@ -586,6 +586,13 @@ static void ath9k_hif_usb_rx_stream(struct hif_device_usb *hif_dev,
 			return;
 		}
 
+		if (pkt_len > 2 * MAX_RX_BUF_SIZE) {
+			dev_err(&hif_dev->udev->dev,
+				"ath9k_htc: invalid pkt_len (%x)\n", pkt_len);
+			RX_STAT_INC(skb_dropped);
+			return;
+		}
+
 		pad_len = 4 - (pkt_len & 0x3);
 		if (pad_len == 4)
 			pad_len = 0;
-- 
2.34.1