Abhishek Kumar <kuabhs@xxxxxxxxxxxx> wrote: > 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 > Co-developed-by: Wen Gong <quic_wgong@xxxxxxxxxxx> > Signed-off-by: Wen Gong <quic_wgong@xxxxxxxxxxx> > Signed-off-by: Abhishek Kumar <kuabhs@xxxxxxxxxxxx> > Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx> > Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx> Patch applied to ath-next branch of ath.git, thanks. b72a4aff947b ath10k: skip ath10k_halt during suspend for driver state RESTARTING -- https://patchwork.kernel.org/project/linux-wireless/patch/20220426221859.v2.1.I650b809482e1af8d0156ed88b5dc2677a0711d46@changeid/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches