WARNING at drivers/gpu/drm/drm_gem_vram_helper.c:284 drm_gem_vram_offset
From: 慕冬亮
Date: Sun Nov 22 2020 - 22:29:49 EST
Hi all,
When I leveraged syzkaller to fuzz this kernel image, the VMs is
always broken with the following WARNING report:
```
[ 18.093341][ T1] ------------[ cut here ]------------
[ 18.093419][ T1] WARNING: CPU: 1 PID: 1 at
drivers/gpu/drm/drm_gem_vram_helper.c:284
drm_gem_vram_offset+0x128/0x140
[ 18.093431][ T1] Modules linked in:
[ 18.093472][ T1] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc1 #2
[ 18.093489][ T1] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS 1.13.0-1ubuntu1 04/01/2014
[ 18.093532][ T1] RIP: 0010:drm_gem_vram_offset+0x128/0x140
[ 18.093574][ T1] Code: 48 c7 c3 ed ff ff ff 31 c0 31 c9 eb b4 8b
7d d4 e8 bd 78 1e fc e9 56 ff ff ff 8b 3a e8 b1 78 1e fc 4d 85 ff 0f
85 6e ff ff ff <0f> 0b 31 c0 31 c9 31 db eb 8d 8b 7d d4 e8 96 78 1e fc
e9 67 ff ff
[ 18.093594][ T1] RSP: 0000:ffff8880125a6718 EFLAGS: 00010246
[ 18.093622][ T1] RAX: 0000000000000000 RBX: ffff8880155efd80
RCX: 00000000151efd80
[ 18.093645][ T1] RDX: ffff8880151efd80 RSI: 0000000000000040
RDI: ffff8880155efd80
[ 18.093669][ T1] RBP: ffff8880125a6748 R08: ffffea000000000f
R09: ffff8880bffd2000
[ 18.093691][ T1] R10: 0000000000000004 R11: 00000000ffffffff
R12: ffff8880155efc00
[ 18.093711][ T1] R13: 0000000000000000 R14: ffff8880125b0a10
R15: 0000000000000000
[ 18.093736][ T1] FS: 0000000000000000(0000)
GS:ffff8880bfd00000(0000) knlGS:0000000000000000
[ 18.093757][ T1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 18.093777][ T1] CR2: 0000000000000000 CR3: 0000000010229001
CR4: 0000000000770ee0
[ 18.093797][ T1] DR0: 0000000000000000 DR1: 0000000000000000
DR2: 0000000000000000
[ 18.093816][ T1] DR3: 0000000000000000 DR6: 00000000fffe0ff0
DR7: 0000000000000400
[ 18.093828][ T1] PKRU: 55555554
[ 18.093839][ T1] Call Trace:
[ 18.093886][ T1] bochs_pipe_enable+0x16f/0x3f0
[ 18.093935][ T1] drm_simple_kms_crtc_enable+0x12e/0x1a0
[ 18.093973][ T1] ? bochs_connector_get_modes+0x1e0/0x1e0
[ 18.094011][ T1] ? drm_simple_kms_crtc_check+0x210/0x210
[ 18.094049][ T1] drm_atomic_helper_commit_modeset_enables+0x362/0x1000
[ 18.094095][ T1] drm_atomic_helper_commit_tail+0xd3/0x860
[ 18.094135][ T1] ? kmsan_get_metadata+0x116/0x180
[ 18.094171][ T1] commit_tail+0x61c/0x7d0
[ 18.094205][ T1] ? kmsan_internal_set_origin+0x85/0xc0
[ 18.094246][ T1] drm_atomic_helper_commit+0xbfe/0xcb0
[ 18.094284][ T1] ? kmsan_get_metadata+0x116/0x180
[ 18.094322][ T1] ? drm_atomic_helper_async_commit+0x780/0x780
[ 18.094361][ T1] drm_atomic_commit+0x192/0x210
[ 18.094400][ T1] drm_client_modeset_commit_atomic+0x700/0xbe0
[ 18.094444][ T1] drm_client_modeset_commit_locked+0x147/0x860
[ 18.094481][ T1] ? drm_master_internal_acquire+0x4a/0xd0
[ 18.094513][ T1] drm_client_modeset_commit+0x98/0x110
[ 18.094551][ T1] __drm_fb_helper_restore_fbdev_mode_unlocked+0x1a7/0x2a0
[ 18.094586][ T1] drm_fb_helper_set_par+0x12a/0x220
[ 18.094620][ T1] ? drm_fb_helper_fill_pixel_fmt+0x780/0x780
[ 18.094646][ T1] fbcon_init+0x1959/0x2910
[ 18.094685][ T1] ? validate_slab+0x30/0x730
[ 18.094714][ T1] ? fbcon_startup+0x1590/0x1590
[ 18.094746][ T1] visual_init+0x3bb/0x7b0
[ 18.094786][ T1] do_bind_con_driver+0x136e/0x1c90
[ 18.094834][ T1] do_take_over_console+0xe0a/0xef0
[ 18.094875][ T1] ? kmsan_get_shadow_origin_ptr+0x84/0xb0
[ 18.094907][ T1] fbcon_fb_registered+0x51c/0xae0
[ 18.094954][ T1] register_framebuffer+0xb68/0xfc0
[ 18.094999][ T1] __drm_fb_helper_initial_config_and_unlock+0x17d2/0x2030
[ 18.095047][ T1] drm_fbdev_client_hotplug+0x7a3/0xe80
[ 18.095085][ T1] drm_fbdev_generic_setup+0x2b9/0x890
[ 18.095124][ T1] bochs_pci_probe+0x7de/0x800
[ 18.095161][ T1] ? qxl_gem_prime_mmap+0x30/0x30
[ 18.095193][ T1] pci_device_probe+0x95f/0xc70
[ 18.095227][ T1] ? pci_uevent+0x7b0/0x7b0
[ 18.095259][ T1] really_probe+0x9af/0x20d0
[ 18.095298][ T1] driver_probe_device+0x234/0x330
[ 18.095334][ T1] device_driver_attach+0x1e8/0x3c0
[ 18.095370][ T1] __driver_attach+0x30d/0x780
[ 18.095399][ T1] ? klist_devices_get+0x10/0x60
[ 18.095431][ T1] ? kmsan_get_metadata+0x116/0x180
[ 18.095463][ T1] bus_for_each_dev+0x252/0x360
[ 18.095493][ T1] ? driver_attach+0xa0/0xa0
[ 18.095527][ T1] driver_attach+0x84/0xa0
[ 18.095558][ T1] bus_add_driver+0x5d6/0xb00
[ 18.095596][ T1] driver_register+0x30c/0x830
[ 18.095632][ T1] __pci_register_driver+0x1fa/0x350
[ 18.095669][ T1] bochs_init+0xd6/0x115
[ 18.095703][ T1] do_one_initcall+0x246/0x7a0
[ 18.095734][ T1] ? qxl_init+0x165/0x165
[ 18.095779][ T1] ? kmsan_get_metadata+0x116/0x180
[ 18.095815][ T1] ? kmsan_get_shadow_origin_ptr+0x84/0xb0
[ 18.095844][ T1] ? qxl_init+0x165/0x165
[ 18.095878][ T1] do_initcall_level+0x2b4/0x34a
[ 18.095913][ T1] do_initcalls+0x123/0x1ba
[ 18.095947][ T1] ? cpu_init_udelay+0xcf/0xcf
[ 18.095978][ T1] do_basic_setup+0x2e/0x31
[ 18.096011][ T1] kernel_init_freeable+0x23f/0x35f
[ 18.096049][ T1] ? rest_init+0x1f0/0x1f0
[ 18.096080][ T1] kernel_init+0x1a/0x670
[ 18.096111][ T1] ? rest_init+0x1f0/0x1f0
[ 18.096141][ T1] ret_from_fork+0x1f/0x30
[ 18.096166][ T1] Kernel panic - not syncing: panic_on_warn set ...
[ 18.096192][ T1] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.10.0-rc1 #2
[ 18.096208][ T1] Hardware name: QEMU Standard PC (i440FX + PIIX,
1996), BIOS 1.13.0-1ubuntu1 04/01/2014
[ 18.096219][ T1] Call Trace:
[ 18.096254][ T1] dump_stack+0x189/0x218
[ 18.096287][ T1] panic+0x38e/0xae4
[ 18.096335][ T1] ? kmsan_get_shadow_origin_ptr+0x84/0xb0
[ 18.096364][ T1] __warn+0x433/0x5c0
[ 18.096402][ T1] ? drm_gem_vram_offset+0x128/0x140
[ 18.096434][ T1] report_bug+0x669/0x880
[ 18.096474][ T1] ? drm_gem_vram_offset+0x128/0x140
[ 18.096506][ T1] handle_bug+0x6f/0xd0
[ 18.096537][ T1] __exc_invalid_op+0x34/0x80
[ 18.096566][ T1] exc_invalid_op+0x30/0x40
[ 18.096603][ T1] asm_exc_invalid_op+0x12/0x20
[ 18.096640][ T1] RIP: 0010:drm_gem_vram_offset+0x128/0x140
[ 18.096674][ T1] Code: 48 c7 c3 ed ff ff ff 31 c0 31 c9 eb b4 8b
7d d4 e8 bd 78 1e fc e9 56 ff ff ff 8b 3a e8 b1 78 1e fc 4d 85 ff 0f
85 6e ff ff ff <0f> 0b 31 c0 31 c9 31 db eb 8d 8b 7d d4 e8 96 78 1e fc
e9 67 ff ff
[ 18.096693][ T1] RSP: 0000:ffff8880125a6718 EFLAGS: 00010246
[ 18.096721][ T1] RAX: 0000000000000000 RBX: ffff8880155efd80
RCX: 00000000151efd80
[ 18.096743][ T1] RDX: ffff8880151efd80 RSI: 0000000000000040
RDI: ffff8880155efd80
[ 18.096767][ T1] RBP: ffff8880125a6748 R08: ffffea000000000f
R09: ffff8880bffd2000
[ 18.096787][ T1] R10: 0000000000000004 R11: 00000000ffffffff
R12: ffff8880155efc00
[ 18.096807][ T1] R13: 0000000000000000 R14: ffff8880125b0a10
R15: 0000000000000000
[ 18.096849][ T1] ? drm_gem_vram_offset+0x79/0x140
[ 18.096884][ T1] bochs_pipe_enable+0x16f/0x3f0
[ 18.096927][ T1] drm_simple_kms_crtc_enable+0x12e/0x1a0
[ 18.096964][ T1] ? bochs_connector_get_modes+0x1e0/0x1e0
[ 18.097001][ T1] ? drm_simple_kms_crtc_check+0x210/0x210
[ 18.097039][ T1] drm_atomic_helper_commit_modeset_enables+0x362/0x1000
[ 18.097083][ T1] drm_atomic_helper_commit_tail+0xd3/0x860
[ 18.097120][ T1] ? kmsan_get_metadata+0x116/0x180
[ 18.097156][ T1] commit_tail+0x61c/0x7d0
[ 18.097190][ T1] ? kmsan_internal_set_origin+0x85/0xc0
[ 18.097230][ T1] drm_atomic_helper_commit+0xbfe/0xcb0
[ 18.097267][ T1] ? kmsan_get_metadata+0x116/0x180
[ 18.097305][ T1] ? drm_atomic_helper_async_commit+0x780/0x780
[ 18.097341][ T1] drm_atomic_commit+0x192/0x210
[ 18.097378][ T1] drm_client_modeset_commit_atomic+0x700/0xbe0
[ 18.097422][ T1] drm_client_modeset_commit_locked+0x147/0x860
[ 18.097459][ T1] ? drm_master_internal_acquire+0x4a/0xd0
[ 18.097491][ T1] drm_client_modeset_commit+0x98/0x110
[ 18.097528][ T1] __drm_fb_helper_restore_fbdev_mode_unlocked+0x1a7/0x2a0
[ 18.097562][ T1] drm_fb_helper_set_par+0x12a/0x220
[ 18.097596][ T1] ? drm_fb_helper_fill_pixel_fmt+0x780/0x780
[ 18.097621][ T1] fbcon_init+0x1959/0x2910
[ 18.097660][ T1] ? validate_slab+0x30/0x730
[ 18.097688][ T1] ? fbcon_startup+0x1590/0x1590
[ 18.097719][ T1] visual_init+0x3bb/0x7b0
[ 18.097758][ T1] do_bind_con_driver+0x136e/0x1c90
[ 18.097807][ T1] do_take_over_console+0xe0a/0xef0
[ 18.097848][ T1] ? kmsan_get_shadow_origin_ptr+0x84/0xb0
[ 18.097879][ T1] fbcon_fb_registered+0x51c/0xae0
[ 18.097917][ T1] register_framebuffer+0xb68/0xfc0
[ 18.097961][ T1] __drm_fb_helper_initial_config_and_unlock+0x17d2/0x2030
[ 18.098009][ T1] drm_fbdev_client_hotplug+0x7a3/0xe80
[ 18.098047][ T1] drm_fbdev_generic_setup+0x2b9/0x890
[ 18.098085][ T1] bochs_pci_probe+0x7de/0x800
[ 18.098123][ T1] ? qxl_gem_prime_mmap+0x30/0x30
[ 18.098152][ T1] pci_device_probe+0x95f/0xc70
[ 18.098187][ T1] ? pci_uevent+0x7b0/0x7b0
[ 18.098217][ T1] really_probe+0x9af/0x20d0
[ 18.098255][ T1] driver_probe_device+0x234/0x330
[ 18.098291][ T1] device_driver_attach+0x1e8/0x3c0
[ 18.098326][ T1] __driver_attach+0x30d/0x780
[ 18.098355][ T1] ? klist_devices_get+0x10/0x60
[ 18.098388][ T1] ? kmsan_get_metadata+0x116/0x180
[ 18.098419][ T1] bus_for_each_dev+0x252/0x360
[ 18.098448][ T1] ? driver_attach+0xa0/0xa0
[ 18.098482][ T1] driver_attach+0x84/0xa0
[ 18.098512][ T1] bus_add_driver+0x5d6/0xb00
[ 18.098550][ T1] driver_register+0x30c/0x830
[ 18.098585][ T1] __pci_register_driver+0x1fa/0x350
[ 18.098620][ T1] bochs_init+0xd6/0x115
[ 18.098651][ T1] do_one_initcall+0x246/0x7a0
[ 18.098680][ T1] ? qxl_init+0x165/0x165
[ 18.098727][ T1] ? kmsan_get_metadata+0x116/0x180
[ 18.098763][ T1] ? kmsan_get_shadow_origin_ptr+0x84/0xb0
[ 18.098791][ T1] ? qxl_init+0x165/0x165
[ 18.098824][ T1] do_initcall_level+0x2b4/0x34a
[ 18.098859][ T1] do_initcalls+0x123/0x1ba
[ 18.098890][ T1] ? cpu_init_udelay+0xcf/0xcf
[ 18.098921][ T1] do_basic_setup+0x2e/0x31
[ 18.098958][ T1] kernel_init_freeable+0x23f/0x35f
[ 18.098993][ T1] ? rest_init+0x1f0/0x1f0
[ 18.099024][ T1] kernel_init+0x1a/0x670
[ 18.099054][ T1] ? rest_init+0x1f0/0x1f0
[ 18.099085][ T1] ret_from_fork+0x1f/0x30
[ 18.099240][ T1] Dumping ftrace buffer:
[ 18.099250][ T1] (ftrace buffer empty)
[ 18.099250][ T1] Kernel Offset: disabled
[ 18.099250][ T1] Rebooting in 1 seconds..
--
My best regards to you.
No System Is Safe!
Dongliang Mu