[PATCH 4.4 33/45] [media] dvb-usb: dont use stack for firmware load

From: Greg Kroah-Hartman
Date: Wed Apr 19 2017 - 10:58:32 EST

4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>

commit 43fab9793c1f44e665b4f98035a14942edf03ddc upstream.

As reported by Marc Duponcheel <marc@xxxxxxxxxx>, firmware load on
dvb-usb is using the stack, with is not allowed anymore on default
Kernel configurations:

[ 1025.958836] dvb-usb: found a 'WideView WT-220U PenType Receiver (based on ZL353)' in cold state, will try to load a firmware
[ 1025.958853] dvb-usb: downloading firmware from file 'dvb-usb-wt220u-zl0353-01.fw'
[ 1025.958855] dvb-usb: could not stop the USB controller CPU.
[ 1025.958856] dvb-usb: error while transferring firmware (transferred size: -11, block size: 3)
[ 1025.958856] dvb-usb: firmware download failed at 8 with -22
[ 1025.958867] usbcore: registered new interface driver dvb_usb_dtt200u

[ 2.789902] dvb-usb: downloading firmware from file 'dvb-usb-wt220u-zl0353-01.fw'
[ 2.789905] ------------[ cut here ]------------
[ 2.789911] WARNING: CPU: 3 PID: 2196 at drivers/usb/core/hcd.c:1584 usb_hcd_map_urb_for_dma+0x430/0x560 [usbcore]
[ 2.789912] transfer buffer not dma capable
[ 2.789912] Modules linked in: btusb dvb_usb_dtt200u(+) dvb_usb_af9035(+) btrtl btbcm dvb_usb dvb_usb_v2 btintel dvb_core bluetooth rc_core rfkill x86_pkg_temp_thermal intel_powerclamp coretemp crc32_pclmul aesni_intel aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd drm_kms_helper syscopyarea sysfillrect pcspkr i2c_i801 sysimgblt fb_sys_fops drm i2c_smbus i2c_core r8169 lpc_ich mfd_core mii thermal fan rtc_cmos video button acpi_cpufreq processor snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd crc32c_intel ahci libahci libata xhci_pci ehci_pci xhci_hcd ehci_hcd usbcore usb_common dm_mirror dm_region_hash dm_log dm_mod
[ 2.789936] CPU: 3 PID: 2196 Comm: systemd-udevd Not tainted 4.9.0-gentoo #1
[ 2.789937] Hardware name: ASUS All Series/H81I-PLUS, BIOS 0401 07/23/2013
[ 2.789938] ffffc9000339b690 ffffffff812bd397 ffffc9000339b6e0 0000000000000000
[ 2.789939] ffffc9000339b6d0 ffffffff81055c86 000006300339b6a0 ffff880116c0c000
[ 2.789941] 0000000000000000 0000000000000000 0000000000000001 ffff880116c08000
[ 2.789942] Call Trace:
[ 2.789945] [<ffffffff812bd397>] dump_stack+0x4d/0x66
[ 2.789947] [<ffffffff81055c86>] __warn+0xc6/0xe0
[ 2.789948] [<ffffffff81055cea>] warn_slowpath_fmt+0x4a/0x50
[ 2.789952] [<ffffffffa006d460>] usb_hcd_map_urb_for_dma+0x430/0x560 [usbcore]
[ 2.789954] [<ffffffff814ed5a8>] ? io_schedule_timeout+0xd8/0x110
[ 2.789956] [<ffffffffa006e09c>] usb_hcd_submit_urb+0x9c/0x980 [usbcore]
[ 2.789958] [<ffffffff812d0ebf>] ? copy_page_to_iter+0x14f/0x2b0
[ 2.789960] [<ffffffff81126818>] ? pagecache_get_page+0x28/0x240
[ 2.789962] [<ffffffff8118c2a0>] ? touch_atime+0x20/0xa0
[ 2.789964] [<ffffffffa006f7c4>] usb_submit_urb+0x2c4/0x520 [usbcore]
[ 2.789967] [<ffffffffa006feca>] usb_start_wait_urb+0x5a/0xe0 [usbcore]
[ 2.789969] [<ffffffffa007000c>] usb_control_msg+0xbc/0xf0 [usbcore]
[ 2.789970] [<ffffffffa067903d>] usb_cypress_writemem+0x3d/0x40 [dvb_usb]
[ 2.789972] [<ffffffffa06791cf>] usb_cypress_load_firmware+0x4f/0x130 [dvb_usb]
[ 2.789973] [<ffffffff8109dbbe>] ? console_unlock+0x2fe/0x5d0
[ 2.789974] [<ffffffff8109e10c>] ? vprintk_emit+0x27c/0x410
[ 2.789975] [<ffffffff8109e40a>] ? vprintk_default+0x1a/0x20
[ 2.789976] [<ffffffff81124d76>] ? printk+0x43/0x4b
[ 2.789977] [<ffffffffa0679310>] dvb_usb_download_firmware+0x60/0xd0 [dvb_usb]
[ 2.789979] [<ffffffffa0679898>] dvb_usb_device_init+0x3d8/0x610 [dvb_usb]
[ 2.789981] [<ffffffffa069e302>] dtt200u_usb_probe+0x92/0xd0 [dvb_usb_dtt200u]
[ 2.789984] [<ffffffffa007420c>] usb_probe_interface+0xfc/0x270 [usbcore]
[ 2.789985] [<ffffffff8138bf95>] driver_probe_device+0x215/0x2d0
[ 2.789986] [<ffffffff8138c0e6>] __driver_attach+0x96/0xa0
[ 2.789987] [<ffffffff8138c050>] ? driver_probe_device+0x2d0/0x2d0
[ 2.789988] [<ffffffff81389ffb>] bus_for_each_dev+0x5b/0x90
[ 2.789989] [<ffffffff8138b7b9>] driver_attach+0x19/0x20
[ 2.789990] [<ffffffff8138b33c>] bus_add_driver+0x11c/0x220
[ 2.789991] [<ffffffff8138c91b>] driver_register+0x5b/0xd0
[ 2.789994] [<ffffffffa0072f6c>] usb_register_driver+0x7c/0x130 [usbcore]
[ 2.789994] [<ffffffffa06a5000>] ? 0xffffffffa06a5000
[ 2.789996] [<ffffffffa06a501e>] dtt200u_usb_driver_init+0x1e/0x20 [dvb_usb_dtt200u]
[ 2.789997] [<ffffffff81000408>] do_one_initcall+0x38/0x140
[ 2.789998] [<ffffffff8116001c>] ? __vunmap+0x7c/0xc0
[ 2.789999] [<ffffffff81124fb0>] ? do_init_module+0x22/0x1d2
[ 2.790000] [<ffffffff81124fe8>] do_init_module+0x5a/0x1d2
[ 2.790002] [<ffffffff810c96b1>] load_module+0x1e11/0x2580
[ 2.790003] [<ffffffff810c68b0>] ? show_taint+0x30/0x30
[ 2.790004] [<ffffffff81177250>] ? kernel_read_file+0x100/0x190
[ 2.790005] [<ffffffff810c9ffa>] SyS_finit_module+0xba/0xc0
[ 2.790007] [<ffffffff814f13e0>] entry_SYSCALL_64_fastpath+0x13/0x94
[ 2.790008] ---[ end trace c78a74e78baec6fc ]---

So, allocate the structure dynamically.

Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/usb/dvb-usb/dvb-usb-firmware.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

--- a/drivers/media/usb/dvb-usb/dvb-usb-firmware.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-firmware.c
@@ -35,29 +35,34 @@ static int usb_cypress_writemem(struct u

int usb_cypress_load_firmware(struct usb_device *udev, const struct firmware *fw, int type)
{
- struct hexline hx;
+ struct hexline *hx;
u8 reset;
int ret,pos=0;

+ hx = kmalloc(sizeof(*hx), GFP_KERNEL);
+ if (!hx)
+ return -ENOMEM;
+
/* stop the CPU */
reset = 1;
if ((ret = usb_cypress_writemem(udev,cypress[type].cpu_cs_register,&reset,1)) != 1)
err("could not stop the USB controller CPU.");

- while ((ret = dvb_usb_get_hexline(fw,&hx,&pos)) > 0) {
- deb_fw("writing to address 0x%04x (buffer: 0x%02x %02x)\n",hx.addr,hx.len,hx.chk);
- ret = usb_cypress_writemem(udev,hx.addr,hx.data,hx.len);
+ while ((ret = dvb_usb_get_hexline(fw, hx, &pos)) > 0) {
+ deb_fw("writing to address 0x%04x (buffer: 0x%02x %02x)\n", hx->addr, hx->len, hx->chk);
+ ret = usb_cypress_writemem(udev, hx->addr, hx->data, hx->len);

- if (ret != hx.len) {
+ if (ret != hx->len) {
err("error while transferring firmware "
"(transferred size: %d, block size: %d)",
- ret,hx.len);
+ ret, hx->len);
ret = -EINVAL;
break;
}
}
if (ret < 0) {
err("firmware download failed at %d with %d",pos,ret);
+ kfree(hx);
return ret;
}

@@ -71,6 +76,8 @@ int usb_cypress_load_firmware(struct usb
} else
ret = -EIO;

+ kfree(hx);
+
return ret;
}
EXPORT_SYMBOL(usb_cypress_load_firmware);