Re: [PATCH net] VSOCK: check sk state before receive

From: Hangbin Liu <liuhangbin@gmail.com>
To: "Jorgen S. Hansen" <jhansen@vmware.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH net] VSOCK: check sk state before receive
Date: Sat, 22 Sep 2018 14:27:44 +0800	[thread overview]
Message-ID: <20180922062744.GC24677@leo.usersys.redhat.com> (raw)
In-Reply-To: <MWHPR05MB3376DF7EC1FEC4E9A4112F3BDA120@MWHPR05MB3376.namprd05.prod.outlook.com>

On Fri, Sep 21, 2018 at 07:48:25AM +0000, Jorgen S. Hansen wrote:
> Hi Hangbin,
> 
> I finaly got to the bottom of this - the issue was indeed in the VMCI driver. The patch is posted here:
> 
> https://lkml.org/lkml/2018/9/21/326
> 
> I used your reproduce.log to test the fix. Thanks for discovering this issue.

Hi Jorgen,

Thanks for your patch. I built a test kernel with your fix, run my
reproducer and syzkaller socket vnet test for a while. There is no such
error. So I think your patch fixed this issue.

BTW, with FAULT_INJECTION enabled. I got another call trace:

[  251.166377] FAULT_INJECTION: forcing a failure.
[  251.178736] CPU: 15 PID: 10448 Comm: syz-executor7 Not tainted 4.19.0-rc4.syz.vnet+ #3
[  251.187577] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.1.5 04/11/2016
[  251.187578] Call Trace:
[  251.187586]  dump_stack+0x8c/0xce
[  251.187594]  should_fail+0x5dd/0x6b0
[  251.199932]  ? fault_create_debugfs_attr+0x1d0/0x1d0
[  251.199937]  __should_failslab+0xe8/0x120
[  251.199945]  should_failslab+0xa/0x20
[  251.228430]  kmem_cache_alloc_trace+0x43/0x1f0
[  251.233392]  ? vhost_dev_set_owner+0x366/0x790 [vhost]
[  251.239129]  vhost_dev_set_owner+0x366/0x790 [vhost]
[  251.244672]  ? vhost_poll_wakeup+0xa0/0xa0 [vhost]
[  251.250018]  ? kasan_unpoison_shadow+0x30/0x40
[  251.254978]  ? vhost_worker+0x370/0x370 [vhost]
[  251.260035]  ? kasan_kmalloc_large+0x71/0xe0
[  251.264799]  ? kmalloc_order+0x54/0x60
[  251.268985]  vhost_net_ioctl+0xc2e/0x14c0 [vhost_net]
[  251.274635]  ? avc_ss_reset+0x150/0x150
[  251.278915]  ? kstrtouint_from_user+0xe5/0x140
[  251.283876]  ? handle_tx_kick+0x40/0x40 [vhost_net]
[  251.289320]  ? save_stack+0x89/0xb0
[  251.293213]  ? __kasan_slab_free+0x12e/0x180
[  251.297979]  ? kmem_cache_free+0x7a/0x210
[  251.302452]  ? putname+0xe2/0x120
[  251.306151]  ? get_pid_task+0x6e/0x90
[  251.310238]  ? proc_fail_nth_write+0x91/0x1c0
[  251.315100]  ? map_files_get_link+0x3c0/0x3c0
[  251.319963]  ? exit_robust_list+0x1c0/0x1c0
[  251.324633]  ? __vfs_write+0xf7/0x6a0
[  251.328711]  ? handle_tx_kick+0x40/0x40 [vhost_net]
[  251.334154]  do_vfs_ioctl+0x1a5/0xfb0
[  251.338241]  ? ioctl_preallocate+0x1c0/0x1c0
[  251.343009]  ? selinux_file_ioctl+0x382/0x560
[  251.347872]  ? selinux_capable+0x40/0x40
[  251.352250]  ? __fget+0x211/0x2e0
[  251.355949]  ? iterate_fd+0x1c0/0x1c0
[  251.360038]  ? syscall_trace_enter+0x285/0xaa0
[  251.365011]  ? security_file_ioctl+0x5d/0xb0
[  251.369776]  ? selinux_capable+0x40/0x40
[  251.374153]  ksys_ioctl+0x89/0xa0
[  251.377853]  __x64_sys_ioctl+0x74/0xb0
[  251.382036]  do_syscall_64+0xc3/0x390
[  251.386123]  ? syscall_return_slowpath+0x14c/0x230
[  251.391473]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  251.397111] RIP: 0033:0x451b89
[  251.400519] Code: fc ff 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b 67 fc ff c3 66 2e 0f 1f 84 00 00 00 00
[  251.421476] RSP: 002b:00007fc0d9673c48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[  251.429927] RAX: ffffffffffffffda RBX: 00007fc0d96746b4 RCX: 0000000000451b89
[  251.437889] RDX: 0000000000000000 RSI: 000000000000af01 RDI: 0000000000000003
[  251.445852] RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
[  251.453815] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
[  251.461778] R13: 0000000000006450 R14: 00000000004d3090 R15: 00007fc0d9674700

Thanks
Hangbin