Is: virtio_gpu_object_shmem_init issues? Was:Re: upstream boot error: general protection fault in swiotlb_map
From: Konrad Rzeszutek Wilk
Date: Mon Aug 24 2020 - 11:10:52 EST
On Thu, Aug 06, 2020 at 03:46:23AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 47ec5303 Merge git://git.kernel.org/pub/scm/linux/kernel/g..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16fe1dea900000
> kernel config: https://syzkaller.appspot.com/x/.config?x=7c06047f622c5724
> dashboard link: https://syzkaller.appspot.com/bug?extid=3f86afd0b1e4bf1cb64c
> compiler: gcc (GCC) 10.1.0-syz 20200507
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+3f86afd0b1e4bf1cb64c@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ceph: loaded (mds proto 32)
> NET: Registered protocol family 38
> async_tx: api initialized (async)
> Key type asymmetric registered
> Asymmetric key parser 'x509' registered
> Asymmetric key parser 'pkcs8' registered
> Key type pkcs7_test registered
> Asymmetric key parser 'tpm_parser' registered
> Block layer SCSI generic (bsg) driver version 0.4 loaded (major 243)
> io scheduler mq-deadline registered
> io scheduler kyber registered
> io scheduler bfq registered
> hgafb: HGA card not detected.
> hgafb: probe of hgafb.0 failed with error -22
> usbcore: registered new interface driver udlfb
> uvesafb: failed to execute /sbin/v86d
> uvesafb: make sure that the v86d helper is installed and executable
> uvesafb: Getting VBE info block failed (eax=0x4f00, err=-2)
> uvesafb: vbe_init() failed with -22
> uvesafb: probe of uvesafb.0 failed with error -22
> vga16fb: mapped to 0x000000008aac772d
> Console: switching to colour frame buffer device 80x30
> fb0: VGA16 VGA frame buffer device
> input: Power Button as /devices/LNXSYSTM:00/LNXPWRBN:00/input/input0
> ACPI: Power Button [PWRF]
> ioatdma: Intel(R) QuickData Technology Driver 5.00
> PCI Interrupt Link [GSIF] enabled at IRQ 21
> PCI Interrupt Link [GSIG] enabled at IRQ 22
> PCI Interrupt Link [GSIH] enabled at IRQ 23
> N_HDLC line discipline registered with maxframe=4096
> Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
> 00:05: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
> Cyclades driver 2.6
> Initializing Nozomi driver 2.1d
> RocketPort device driver module, version 2.09, 12-June-2003
> No rocketport ports found; unloading driver
> Non-volatile memory driver v1.3
> Linux agpgart interface v0.103
> [drm] Initialized vgem 1.0.0 20120112 for vgem on minor 0
> [drm] Initialized vkms 1.0.0 20180514 for vkms on minor 1
> usbcore: registered new interface driver udl
> [drm] pci: virtio-vga detected at 0000:00:01.0
> fb0: switching to virtiodrmfb from VGA16 VGA
> Console: switching to colour VGA+ 80x25
> virtio-pci 0000:00:01.0: vgaarb: deactivate vga console
> Console: switching to colour dummy device 80x25
> [drm] features: -virgl +edid
> [drm] number of scanouts: 1
> [drm] number of cap sets: 0
> [drm] Initialized virtio_gpu 0.1.0 0 for virtio0 on minor 2
> general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-syzkaller #0
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
> RIP: 0010:swiotlb_map+0x5ac/0x700 kernel/dma/swiotlb.c:683
> Code: 28 04 00 00 48 c1 ea 03 80 3c 02 00 0f 85 4d 01 00 00 4c 8b a5 18 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 1e 01 00 00 48 8d 7d 50 4d 8b 24 24 48 b8 00 00
> RSP: 0000:ffffc9000034f3e0 EFLAGS: 00010246
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8162cc1d
> RDX: 0000000000000000 RSI: ffffffff8162cc98 RDI: ffff88802971a470
> RBP: ffff88802971a048 R08: 0000000000000001 R09: ffffffff8c5dba77
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 000000007ac00000 R14: dffffc0000000000 R15: 0000000000001000
> FS: 0000000000000000(0000) GS:ffff88802ce00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00000000ffffffff CR3: 0000000009a8d000 CR4: 0000000000350ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> dma_direct_map_page include/linux/dma-direct.h:170 [inline]
> dma_direct_map_sg+0x3bb/0x670 kernel/dma/direct.c:368
> dma_map_sg_attrs+0xd0/0x160 kernel/dma/mapping.c:183
> drm_gem_shmem_get_pages_sgt drivers/gpu/drm/drm_gem_shmem_helper.c:700 [inline]
> drm_gem_shmem_get_pages_sgt+0x1fc/0x310 drivers/gpu/drm/drm_gem_shmem_helper.c:679
> virtio_gpu_object_shmem_init drivers/gpu/drm/virtio/virtgpu_object.c:153 [inline]
> virtio_gpu_object_create+0x2fd/0xa70 drivers/gpu/drm/virtio/virtgpu_object.c:232
> virtio_gpu_gem_create drivers/gpu/drm/virtio/virtgpu_gem.c:45 [inline]
> virtio_gpu_mode_dumb_create+0x298/0x530 drivers/gpu/drm/virtio/virtgpu_gem.c:85
> drm_mode_create_dumb+0x27c/0x300 drivers/gpu/drm/drm_dumb_buffers.c:94
> drm_client_buffer_create drivers/gpu/drm/drm_client.c:267 [inline]
> drm_client_framebuffer_create+0x1b7/0x770 drivers/gpu/drm/drm_client.c:412
> drm_fb_helper_generic_probe+0x1e5/0x810 drivers/gpu/drm/drm_fb_helper.c:2086
> drm_fb_helper_single_fb_probe drivers/gpu/drm/drm_fb_helper.c:1635 [inline]
> __drm_fb_helper_initial_config_and_unlock+0xbc6/0x12d0 drivers/gpu/drm/drm_fb_helper.c:1793
> drm_fb_helper_initial_config drivers/gpu/drm/drm_fb_helper.c:1888 [inline]
> drm_fb_helper_initial_config drivers/gpu/drm/drm_fb_helper.c:1880 [inline]
> drm_fbdev_client_hotplug+0x2d4/0x580 drivers/gpu/drm/drm_fb_helper.c:2180
> drm_fbdev_generic_setup+0x1c8/0x450 drivers/gpu/drm/drm_fb_helper.c:2262
> virtio_gpu_probe+0x28f/0x2e0 drivers/gpu/drm/virtio/virtgpu_drv.c:127
> virtio_dev_probe+0x445/0x6f0 drivers/virtio/virtio.c:248
> really_probe+0x282/0x9f0 drivers/base/dd.c:553
> driver_probe_device+0xfe/0x1d0 drivers/base/dd.c:738
> device_driver_attach+0x228/0x290 drivers/base/dd.c:1013
> __driver_attach drivers/base/dd.c:1090 [inline]
> __driver_attach+0xda/0x240 drivers/base/dd.c:1044
> bus_for_each_dev+0x147/0x1d0 drivers/base/bus.c:305
> bus_add_driver+0x348/0x5a0 drivers/base/bus.c:622
> driver_register+0x220/0x3a0 drivers/base/driver.c:171
> do_one_initcall+0x10a/0x7b0 init/main.c:1201
> do_initcall_level init/main.c:1274 [inline]
> do_initcalls init/main.c:1290 [inline]
> do_basic_setup init/main.c:1310 [inline]
> kernel_init_freeable+0x589/0x638 init/main.c:1505
> kernel_init+0xd/0x1c0 init/main.c:1399
> ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
> Modules linked in:
> ---[ end trace 11a290451cfd19ed ]---
> RIP: 0010:swiotlb_map+0x5ac/0x700 kernel/dma/swiotlb.c:683
> Code: 28 04 00 00 48 c1 ea 03 80 3c 02 00 0f 85 4d 01 00 00 4c 8b a5 18 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 1e 01 00 00 48 8d 7d 50 4d 8b 24 24 48 b8 00 00
> RSP: 0000:ffffc9000034f3e0 EFLAGS: 00010246
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8162cc1d
> RDX: 0000000000000000 RSI: ffffffff8162cc98 RDI: ffff88802971a470
> RBP: ffff88802971a048 R08: 0000000000000001 R09: ffffffff8c5dba77
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 000000007ac00000 R14: dffffc0000000000 R15: 0000000000001000
> FS: 0000000000000000(0000) GS:ffff88802ce00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00000000ffffffff CR3: 0000000009a8d000 CR4: 0000000000350ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
So it fails at
683 dev_WARN_ONCE(dev, 1,
684 "swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
685 &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
which makes no sense to me as `dev` surely exists. I can see in the console log:
virtio-pci 0000:00:01.0: vgaarb: deactivate vga console
So what gives?
Code: 28 04 00 00 48 c1 ea 03 80 3c 02 00 0f 85 4d 01 00 00 4c 8b a5 18 04 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 1e 01 00 00 48 8d 7d 50 4d 8b 24 24 48 b8 00 00
is
All code
========
0: 28 04 00 sub %al,(%rax,%rax,1)
3: 00 48 c1 add %cl,-0x3f(%rax)
6: ea (bad)
7: 03 80 3c 02 00 0f add 0xf00023c(%rax),%eax
d: 85 4d 01 test %ecx,0x1(%rbp)
10: 00 00 add %al,(%rax)
12: 4c 8b a5 18 04 00 00 mov 0x418(%rbp),%r12
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 4c 89 e2 mov %r12,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
2a:* 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
2e: 0f 85 1e 01 00 00 jne 0x152
34: 48 8d 7d 50 lea 0x50(%rbp),%rdi
38: 4d 8b 24 24 mov (%r12),%r12
3c: 48 rex.W
3d: b8 .byte 0xb8
So %r12 was expected to have something valid, put in %rdx, and shifted by three (line 26). Then
we fetch from
base = 0000000000000000 (%rdx) + 0xdffffc0000000000(%rax)* scale 1.
and compare against 0 (if I am reading this right).
No clue here.
I tried compiling the upstream kernel with the .config mentioned at the top
but sadly I can't find anything that similar to this code to figure out
what exactly it is trying to access and crash.
CC-ing a fellow engineer who is debugging this, but it looks to be related to VirtIO DRM.
>
>
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