>From 47fdaac830354fdf1775cd6e41a545148557e6e7 Mon Sep 17 00:00:00 2001 From: Vandana BN Date: Wed, 17 Jul 2019 02:48:06 +0530 Subject: [PATCH] media:dvb-frontends:Remove dvb_pll_devcount and id module parameters. Syzbot reported global-out-of-bounds Read in dvb_pll_attach, while accessing id[dvb_pll_devcount], because dvb_pll_devcount was 65, that is more than size of 'id' which is DVB_PLL_MAX(64). Fix would be to check if DVB_PLL_MAX devices are attached and if so return NULL from dvb_pll_attach(). But this will put a limit on the number of devices that can be attached. Also dvb_pll_devcount and "id" module parameter are used for debugging purpose to override/force PLL type. So this patch removes these module parameters. Reported-by: syz...@syzkaller.appspotmail.com usb 1-1: dvb_usb_v2: will pass the complete MPEG2 transport stream to the software demuxer dvbdev: DVB: registering new adapter (774 Friio White ISDB-T USB2.0) usb 1-1: media controller created dvbdev: dvb_create_media_entity: media entity 'dvb-demux' registered. tc90522 0-0018: Toshiba TC90522 attached. usb 1-1: DVB: registering adapter 0 frontend 0 (Toshiba TC90522 ISDB-T module)... dvbdev: dvb_create_media_entity: media entity 'Toshiba TC90522 ISDB-T module' registered. ================================================================== BUG: KASAN: global-out-of-bounds in dvb_pll_attach+0x6c5/0x830 drivers/media/dvb-frontends/dvb-pll.c:798 Read of size 4 at addr ffffffff89c9e5e0 by task kworker/0:1/12 CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.2.0-rc6+ #13 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xca/0x13e lib/dump_stack.c:113 print_address_description+0x67/0x231 mm/kasan/report.c:188 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:317 kasan_report+0xe/0x20 mm/kasan/common.c:614 dvb_pll_attach+0x6c5/0x830 drivers/media/dvb-frontends/dvb-pll.c:798 dvb_pll_probe+0xfe/0x174 drivers/media/dvb-frontends/dvb-pll.c:877 i2c_device_probe+0x790/0xaa0 drivers/i2c/i2c-core-base.c:389 really_probe+0x281/0x660 drivers/base/dd.c:509 driver_probe_device+0x104/0x210 drivers/base/dd.c:670 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:843 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2111 i2c_new_client_device+0x5b3/0xc40 drivers/i2c/i2c-core-base.c:778 i2c_new_device+0x19/0x50 drivers/i2c/i2c-core-base.c:821 dvb_module_probe+0xf9/0x220 drivers/media/dvb-core/dvbdev.c:985 friio_tuner_attach+0x125/0x1d0 drivers/media/usb/dvb-usb-v2/gl861.c:536 dvb_usbv2_adapter_frontend_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:675 [inline] dvb_usbv2_adapter_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:804 [inline] dvb_usbv2_init drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:865 [inline] dvb_usbv2_probe.cold+0x24dc/0x255d drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:980 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 really_probe+0x281/0x660 drivers/base/dd.c:509 driver_probe_device+0x104/0x210 drivers/base/dd.c:670 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:843 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2111 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266 really_probe+0x281/0x660 drivers/base/dd.c:509 driver_probe_device+0x104/0x210 drivers/base/dd.c:670 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454 __device_attach+0x217/0x360 drivers/base/dd.c:843 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514 device_add+0xae6/0x16f0 drivers/base/core.c:2111 usb_new_device.cold+0x8c1/0x1016 drivers/usb/core/hub.c:2534 hub_port_connect drivers/usb/core/hub.c:5089 [inline] hub_port_connect_change drivers/usb/core/hub.c:5204 [inline] port_event drivers/usb/core/hub.c:5350 [inline] hub_event+0x1ada/0x3590 drivers/usb/core/hub.c:5432 process_one_work+0x905/0x1570 kernel/workqueue.c:2269 process_scheduled_works kernel/workqueue.c:2331 [inline] worker_thread+0x7ab/0xe20 kernel/workqueue.c:2417 kthread+0x30b/0x410 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the variable: id+0x100/0x120 Memory state around the buggy address: ffffffff89c9e480: fa fa fa fa 00 00 fa fa fa fa fa fa 00 00 00 00 ffffffff89c9e500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffffffff89c9e580: 00 00 00 00 00 00 00 00 00 00 00 00 fa fa fa fa ^ ffffffff89c9e600: 04 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa ffffffff89c9e680: 04 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa ================================================================== Signed-off-by: Vandana BN --- drivers/media/dvb-frontends/dvb-pll.c | 19 +++---------------- 1 file changed, 3 insertions(+), 16 deletions(-) diff --git a/drivers/media/dvb-frontends/dvb-pll.c b/drivers/media/dvb-frontends/dvb-pll.c index ba0c49107bd2..c3a04751e9cf 100644 --- a/drivers/media/dvb-frontends/dvb-pll.c +++ b/drivers/media/dvb-frontends/dvb-pll.c @@ -33,19 +33,11 @@ struct dvb_pll_priv { u32 bandwidth; }; -#define DVB_PLL_MAX 64 - -static unsigned int dvb_pll_devcount; static int debug; module_param(debug, int, 0644); MODULE_PARM_DESC(debug, "enable verbose debug messages"); -static unsigned int id[DVB_PLL_MAX] = - { [ 0 ... (DVB_PLL_MAX-1) ] = DVB_PLL_UNDEFINED }; -module_param_array(id, int, NULL, 0644); -MODULE_PARM_DESC(id, "force pll id to use (DEBUG ONLY)"); - /* ----------------------------------------------------------- */ struct dvb_pll_desc { @@ -795,10 +787,6 @@ struct dvb_frontend *dvb_pll_attach(struct dvb_frontend *fe, int pll_addr, b1[0] = 0; msg.buf = b1; - if ((id[dvb_pll_devcount] > DVB_PLL_UNDEFINED) && - (id[dvb_pll_devcount] < ARRAY_SIZE(pll_list))) - pll_desc_id = id[dvb_pll_devcount]; - BUG_ON(pll_desc_id < 1 || pll_desc_id >= ARRAY_SIZE(pll_list)); desc = pll_list[pll_desc_id]; @@ -825,7 +813,7 @@ struct dvb_frontend *dvb_pll_attach(struct dvb_frontend *fe, int pll_addr, priv->pll_i2c_address = pll_addr; priv->i2c = i2c; priv->pll_desc = desc; - priv->nr = dvb_pll_devcount++; + priv->nr = pll_desc_id; memcpy(&fe->ops.tuner_ops, &dvb_pll_tuner_ops, sizeof(struct dvb_tuner_ops)); @@ -846,13 +834,12 @@ struct dvb_frontend *dvb_pll_attach(struct dvb_frontend *fe, int pll_addr, fe->tuner_priv = priv; - if ((debug) || (id[priv->nr] == pll_desc_id)) { + if (debug) { dprintk("dvb-pll[%d]", priv->nr); if (i2c != NULL) pr_cont(" %d-%04x", i2c_adapter_id(i2c), pll_addr); pr_cont(": id# %d (%s) attached, %s\n", pll_desc_id, desc->name, - id[priv->nr] == pll_desc_id ? - "insmod option" : "autodetected"); + "insmod option"); } kfree(b1); -- 2.17.1