CVE-2022-49519

In the Linux kernel, the following vulnerability has been resolved:

ath10k: skip ath10k_halt during suspend for driver state RESTARTING

Double free crash is observed when FW recovery(caused by wmi

timeout/crash) is followed by immediate suspend event. The FW recovery

is triggered by ath10k_core_restart() which calls driver clean up via

ath10k_halt(). When the suspend event occurs between the FW recovery,

the restart worker thread is put into frozen state until suspend completes.

The suspend event triggers ath10k_stop() which again triggers ath10k_halt()

The double invocation of ath10k_halt() causes ath10k_htt_rx_free() to be

called twice(Note: ath10k_htt_rx_alloc was not called by restart worker

thread because of its frozen state), causing the crash.

To fix this, during the suspend flow, skip call to ath10k_halt() in

ath10k_stop() when the current driver state is ATH10K_STATE_RESTARTING.

Also, for driver state ATH10K_STATE_RESTARTING, call

ath10k_wait_for_suspend() in ath10k_stop(). This is because call to

ath10k_wait_for_suspend() is skipped later in

[ath10k_halt() > ath10k_core_stop()] for the driver state

ATH10K_STATE_RESTARTING.

The frozen restart worker thread will be cancelled during resume when the

device comes out of suspend.

Below is the crash stack for reference:

[ 428.469167] ------------[ cut here ]------------

[ 428.469180] kernel BUG at mm/slub.c:4150!

[ 428.469193] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI

[ 428.469219] Workqueue: events_unbound async_run_entry_fn

[ 428.469230] RIP: 0010:kfree+0x319/0x31b

[ 428.469241] RSP: 0018:ffffa1fac015fc30 EFLAGS: 00010246

[ 428.469247] RAX: ffffedb10419d108 RBX: ffff8c05262b0000

[ 428.469252] RDX: ffff8c04a8c07000 RSI: 0000000000000000

[ 428.469256] RBP: ffffa1fac015fc78 R08: 0000000000000000

[ 428.469276] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

[ 428.469285] Call Trace:

[ 428.469295] ? dma_free_attrs+0x5f/0x7d

[ 428.469320] ath10k_core_stop+0x5b/0x6f

[ 428.469336] ath10k_halt+0x126/0x177

[ 428.469352] ath10k_stop+0x41/0x7e

[ 428.469387] drv_stop+0x88/0x10e

[ 428.469410] __ieee80211_suspend+0x297/0x411

[ 428.469441] rdev_suspend+0x6e/0xd0

[ 428.469462] wiphy_suspend+0xb1/0x105

[ 428.469483] ? name_show+0x2d/0x2d

[ 428.469490] dpm_run_callback+0x8c/0x126

[ 428.469511] ? name_show+0x2d/0x2d

[ 428.469517] __device_suspend+0x2e7/0x41b

[ 428.469523] async_suspend+0x1f/0x93

[ 428.469529] async_run_entry_fn+0x3d/0xd1

[ 428.469535] process_one_work+0x1b1/0x329

[ 428.469541] worker_thread+0x213/0x372

[ 428.469547] kthread+0x150/0x15f

[ 428.469552] ? pr_cont_work+0x58/0x58

[ 428.469558] ? kthread_blkcg+0x31/0x31

Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00288-QCARMSWPZ-1