Subject: Re: vhost && kernel BUG at /build/linux/mm/slub.c:3352!

From: "Michael S. Tsirkin" <[email-masked]>
Date: Wed, 5 Jun 2013 14:54:08 +0300

On Tue, Jun 04, 2013 at 09:50:59PM +0300, Tommi Rantala wrote:
> Hello,
> 
> Hit this right after killing trinity with Ctrl-C. Was fuzzing
> v3.10-rc4-0-gd683b96 in a qemu virtual machine as the root user.
> 
> Tommi

Thanks a lot for the report. If found some bugs when looking
at this: I think they were introduced by
2839400f8fe28ce216eeeba3fb97bdf90977f7ad
though I don't exactly see how ctrl-c can trigger this.
I'll work on patches - is this reproducible at all?

> [29175] Random reseed: 3970521611
> [29175] Random reseed: 202886419
> [29175] Random reseed: 2930978521
> [179904.099501] binder: 29175:2539 ioctl 4010630e fff returned -22
> [29175] Random reseed: 2776471322
> [29175] Random reseed: 3086119361
> child 2606 exiting
> [29175] Bailing main loop. Exit reason: ctrl-c
> [179906.393060] ------------[ cut here ]------------
> [179906.396341] kernel BUG at /build/linux/mm/slub.c:3352!
> [179906.399693] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
> [179906.403272] CPU: 0 PID: 29175 Comm: trinity-main Not tainted 3.10.0-rc4 #1
> [179906.407692] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
> [179906.411475] task: ffff8800b69e47c0 ti: ffff880092f2e000 task.ti:
> ffff880092f2e000
> [179906.416305] RIP: 0010:[<ffffffff81225255>]  [<ffffffff81225255>]
> kfree+0x155/0x2c0
> [179906.421462] RSP: 0000:ffff880092f2fdb0  EFLAGS: 00010246
> [179906.424983] RAX: 0100000000000000 RBX: ffff88009e588000 RCX:
> 0000000000000000
> [179906.429746] RDX: ffff8800b69e47c0 RSI: 00000000000a0004 RDI:
> ffff88009e588000
> [179906.434499] RBP: ffff880092f2fdd8 R08: 0000000000000001 R09:
> 0000000000000000
> [179906.439226] R10: 0000000000000000 R11: 0000000000000001 R12:
> 0000000000000000
> [179906.443835] R13: ffffea0002796200 R14: ffff8800b9a960f8 R15:
> ffff8800ba06f6a0
> [179906.448470] FS:  00007f04cd25c700(0000) GS:ffff8800bf600000(0000)
> knlGS:0000000000000000
> [179906.453857] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [179906.456956] CR2: 00007f98e29d8f50 CR3: 000000009294a000 CR4:
> 00000000000006f0
> [179906.460558] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> 0000000000000000
> [179906.464059] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
> 0000000000000400
> [179906.467617] Stack:
> [179906.468704]  ffff88001a7c0000 0000000000000000 0000000000000000
> ffff8800b9a960f8
> [179906.472638]  ffff8800ba06f6a0 ffff880092f2fdf0 ffffffff81c1c6df
> ffff88001a7c0000
> [179906.476583]  ffff880092f2fe18 ffffffff81c1c771 ffff8800b69718c0
> 0000000000000008
> [179906.480377] Call Trace:
> [179906.481636]  [<ffffffff81c1c6df>] vhost_net_vq_reset+0x7f/0xb0
> [179906.484611]  [<ffffffff81c1c771>] vhost_net_release+0x61/0xb0
> [179906.487481]  [<ffffffff8123237a>] __fput+0x12a/0x230
> [179906.489968]  [<ffffffff81232489>] ____fput+0x9/0x10
> [179906.492422]  [<ffffffff8113a79e>] task_work_run+0xae/0xf0
> [179906.495169]  [<ffffffff811172bc>] do_exit+0x44c/0xb40
> [179906.497789]  [<ffffffff822a24d8>] ? retint_swapgs+0x13/0x1b
> [179906.500652]  [<ffffffff81117a74>] do_group_exit+0x84/0xd0
> [179906.503348]  [<ffffffff81117ad2>] SyS_exit_group+0x12/0x20
> [179906.506146]  [<ffffffff822a2e29>] system_call_fastpath+0x16/0x1b
> [179906.509147] Code: 49 c1 ed 0c 49 c1 e5 06 49 01 c5 49 8b 45 00 f6
> c4 80 74 0a 4d 8b 6d 30 66 0f 1f 44 00 00 49 8b 45 00 a8 80 75 28 f6
> c4 c0 75 02 <0f> 0b 49 8b 45 00 31 f6 f6 c4 40 74 04 41 8b 75 68 4c 89
> ef e8
> [179906.522213] RIP  [<ffffffff81225255>] kfree+0x155/0x2c0
> [179906.524937]  RSP <ffff880092f2fdb0>
> [179906.575627] ---[ end trace 3d4ce10faaa29990 ]---
> [179906.577103] Fixing recursive fault but reboot is needed!
> [29174] Watchdog exiting