Re: [syzbot] WARNING in __vmalloc_node_range

[Uladzislau Rezki <urezki@gmail.com>]

> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    d665ea6e Merge tag 'for-linus-5.13-rc1' of git://git.kerne..
> git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> console output: https://syzkaller.appspot.com/x/log.txt?x=148bff43d00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=f635d6ce17da8a68
> dashboard link: https://syzkaller.appspot.com/bug?extid=7336195c02c1bd2f64e1
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16e963e1d00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=116eec2dd00000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+7336195c02c1bd2f64e1@syzkaller.appspotmail.com
> 
> usb 1-1: media controller created
> dvbdev: dvb_create_media_entity: media entity 'dvb-demux' registered.
> cxusb: set interface failed
> dvb-usb: bulk message failed: -22 (1/0)
> DVB: Unable to find symbol mt352_attach()
> dvb-usb: no frontend was attached by 'DViCO FusionHDTV DVB-T USB (LGZ201)'
> dvbdev: DVB: registering new adapter (DViCO FusionHDTV DVB-T USB (LGZ201))
> usb 1-1: media controller created
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 7 at mm/vmalloc.c:2873 __vmalloc_node_range+0x769/0x970 mm/vmalloc.c:2873
> Modules linked in:
> CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.12.0-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: usb_hub_wq hub_event
> RIP: 0010:__vmalloc_node_range+0x769/0x970 mm/vmalloc.c:2873
> Code: c7 04 24 00 00 00 00 eb 93 e8 93 b7 d9 ff 44 89 fa 44 89 f6 4c 89 ef e8 75 20 07 00 48 89 04 24 e9 be fb ff ff e8 77 b7 d9 ff <0f> 0b 48 c7 04 24 00 00 00 00 e9 63 ff ff ff e8 63 b7 d9 ff 8b 7c
> RSP: 0018:ffffc9000007ee30 EFLAGS: 00010293
> RAX: 0000000000000000 RBX: ffffffff8403d464 RCX: 0000000000000000
> RDX: ffff888100283680 RSI: ffffffff81673599 RDI: 0000000000000003
> RBP: 0000000000000001 R08: 0000000000000000 R09: 8000000000000163
> R10: ffffffff81672ed2 R11: 0000000000000000 R12: 0000000000000000
> R13: ffffc90000000000 R14: dffffc0000000000 R15: 00000000ffffffff
> FS:  0000000000000000(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fffeb9f7c40 CR3: 00000001033f2000 CR4: 00000000001506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  __vmalloc_node mm/vmalloc.c:2963 [inline]
>  vmalloc+0x67/0x80 mm/vmalloc.c:2996
>  dvb_dmx_init+0xe4/0xb90 drivers/media/dvb-core/dvb_demux.c:1251
>  dvb_usb_adapter_dvb_init+0x564/0x860 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:184
>  dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:86 [inline]
>  dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:184 [inline]
>  dvb_usb_device_init.cold+0xc94/0x146e drivers/media/usb/dvb-usb/dvb-usb-init.c:308
>  cxusb_probe+0x159/0x5e0 drivers/media/usb/dvb-usb/cxusb.c:1634
>  usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396
>  really_probe+0x291/0xf60 drivers/base/dd.c:576
>  driver_probe_device+0x298/0x410 drivers/base/dd.c:763
>  __device_attach_driver+0x203/0x2c0 drivers/base/dd.c:870
>  bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431
>  __device_attach+0x228/0x4b0 drivers/base/dd.c:938
>  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
>  device_add+0xbe0/0x2100 drivers/base/core.c:3319
>  usb_set_configuration+0x113f/0x1910 drivers/usb/core/message.c:2164
>  usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238
>  usb_probe_device+0xd9/0x2c0 drivers/usb/core/driver.c:293
>  really_probe+0x291/0xf60 drivers/base/dd.c:576
>  driver_probe_device+0x298/0x410 drivers/base/dd.c:763
>  __device_attach_driver+0x203/0x2c0 drivers/base/dd.c:870
>  bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:431
>  __device_attach+0x228/0x4b0 drivers/base/dd.c:938
>  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
>  device_add+0xbe0/0x2100 drivers/base/core.c:3319
>  usb_new_device.cold+0x721/0x1058 drivers/usb/core/hub.c:2556
>  hub_port_connect drivers/usb/core/hub.c:5276 [inline]
>  hub_port_connect_change drivers/usb/core/hub.c:5416 [inline]
>  port_event drivers/usb/core/hub.c:5562 [inline]
>  hub_event+0x2357/0x4320 drivers/usb/core/hub.c:5644
>  process_one_work+0x98d/0x1580 kernel/workqueue.c:2275
>  worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
>  kthread+0x38c/0x460 kernel/kthread.c:313
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
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> 
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> syzbot can test patches for this issue, for details see:
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Seems like vmalloc() is called with zero size passed:

<snip>
void *__vmalloc_node_range(unsigned long size, unsigned long align,
			unsigned long start, unsigned long end, gfp_t gfp_mask,
			pgprot_t prot, unsigned long vm_flags, int node,
			const void *caller)
{
	struct vm_struct *area;
	void *addr;
	unsigned long real_size = size;
	unsigned long real_align = align;
	unsigned int shift = PAGE_SHIFT;

2873	if (WARN_ON_ONCE(!size))
		return NULL;
<snip>

from the dvb_dmx_init() driver:

<snip>
int dvb_dmx_init(struct dvb_demux *dvbdemux)
{
	int i;
	struct dmx_demux *dmx = &dvbdemux->dmx;

	dvbdemux->cnt_storage = NULL;
	dvbdemux->users = 0;
1251	dvbdemux->filter = vmalloc(array_size(sizeof(struct dvb_demux_filter),
<snip>					      dvbdemux->filternum));

--
Vlad Rezki