4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx> [ Upstream commit 373c83a801f15b1e3d02d855fad89112bd4ccbe0 ] Using built-in in kernel image without a firmware in filesystem or in the kernel image can lead to a kernel NULL pointer deference. Watchdog need to be stopped in brcmf_sdio_remove The system is going down NOW! [ 1348.110759] Unable to handle kernel NULL pointer dereference at virtual address 000002f8 Sent SIGTERM to all processes [ 1348.121412] Mem abort info: [ 1348.126962] ESR = 0x96000004 [ 1348.130023] Exception class = DABT (current EL), IL = 32 bits [ 1348.135948] SET = 0, FnV = 0 [ 1348.138997] EA = 0, S1PTW = 0 [ 1348.142154] Data abort info: [ 1348.145045] ISV = 0, ISS = 0x00000004 [ 1348.148884] CM = 0, WnR = 0 [ 1348.151861] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____) [ 1348.158475] [00000000000002f8] pgd=0000000000000000 [ 1348.163364] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 1348.168927] Modules linked in: ipv6 [ 1348.172421] CPU: 3 PID: 1421 Comm: brcmf_wdog/mmc0 Not tainted 4.17.0-rc5-next-20180517 #18 [ 1348.180757] Hardware name: Amarula A64-Relic (DT) [ 1348.185455] pstate: 60000005 (nZCv daif -PAN -UAO) [ 1348.190251] pc : brcmf_sdiod_freezer_count+0x0/0x20 [ 1348.195124] lr : brcmf_sdio_watchdog_thread+0x64/0x290 [ 1348.200253] sp : ffff00000b85be30 [ 1348.203561] x29: ffff00000b85be30 x28: 0000000000000000 [ 1348.208868] x27: ffff00000b6cb918 x26: ffff80003b990638 [ 1348.214176] x25: ffff0000087b1a20 x24: ffff80003b94f800 [ 1348.219483] x23: ffff000008e620c8 x22: ffff000008f0b660 [ 1348.224790] x21: ffff000008c6a858 x20: 00000000fffffe00 [ 1348.230097] x19: ffff80003b94f800 x18: 0000000000000001 [ 1348.235404] x17: 0000ffffab2e8a74 x16: ffff0000080d7de8 [ 1348.240711] x15: 0000000000000000 x14: 0000000000000400 [ 1348.246018] x13: 0000000000000400 x12: 0000000000000001 [ 1348.251324] x11: 00000000000002c4 x10: 0000000000000a10 [ 1348.256631] x9 : ffff00000b85bc40 x8 : ffff80003be11870 [ 1348.261937] x7 : ffff80003dfc7308 x6 : 000000078ff08b55 [ 1348.267243] x5 : 00000139e1058400 x4 : 0000000000000000 [ 1348.272550] x3 : dead000000000100 x2 : 958f2788d6618100 [ 1348.277856] x1 : 00000000fffffe00 x0 : 0000000000000000 Signed-off-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx> Acked-by: Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> Tested-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/brcm80211/brcmfmac/sdio.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/net/wireless/brcm80211/brcmfmac/sdio.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/sdio.c @@ -4291,6 +4291,13 @@ void brcmf_sdio_remove(struct brcmf_sdio brcmf_dbg(TRACE, "Enter\n"); if (bus) { + /* Stop watchdog task */ + if (bus->watchdog_tsk) { + send_sig(SIGTERM, bus->watchdog_tsk, 1); + kthread_stop(bus->watchdog_tsk); + bus->watchdog_tsk = NULL; + } + /* De-register interrupt handler */ brcmf_sdiod_intr_unregister(bus->sdiodev);