On Wed Sep 18 19, Patrick Uiterwijk wrote:
On Wed, 18 Sep 2019 at 09:25, Jerry Snitselaar <jsnitsel@xxxxxxxxxx> wrote:
On Tue Sep 17 19, Jerry Snitselaar wrote:
>On Tue Sep 17 19, Jerry Snitselaar wrote:
>>On Thu Aug 01 19, Jerry Snitselaar wrote:
>>>Hi Matthew, cc'ing as this might have something to do with the recent
>>>changes to tpm_read_log_efi.
>>>
>>>On Thu Aug 01 19, Jerry Snitselaar wrote:
>>>>I've had a couple reports emailed to me with a trace like the following
>>>>for 5.3-rc1 and 5.3-rc2. I'm just starting to dig into and look at recent
>>>>commits and mailing list, but is this already known?
>>>>
>>>>It's been reported on a couple different Lenovo laptop models (T470s and X1 carbon I believe).
>>>>
>>>>Full panic message:
>>>>[ 0.774340] BUG: unable to handle page fault for address: ffffbc8fc00866ad
>>>>[ 0.774788] #PF: supervisor read access in kernel mode
>>>>[ 0.774788] #PF: error_code(0x0000) - not-present page
>>>>[ 0.774788] PGD 107d36067 P4D 107d36067 PUD 107d37067 PMD 107d38067 PTE 0
>>>>[ 0.774788] Oops: 0000 [#1] SMP PTI
>>>>[ 0.774788] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.3.0-0.rc2.1.elrdy.x86_64 #1
>>>>[ 0.774788] Hardware name: LENOVO 20HGS22D0W/20HGS22D0W, BIOS N1WET51W (1.30 ) 09/14/2018
>>>>[ 0.774788] RIP: 0010:memcpy_erms+0x6/0x10
>>>>[ 0.774788] Code: 90 90 90 90 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe
>>>>[ 0.774788] RSP: 0000:ffffbc8fc0073b30 EFLAGS: 00010286
>>>>[ 0.774788] RAX: ffff9b1fc7c5b367 RBX: ffff9b1fc8390000 RCX: ffffffffffffe962
>>>>[ 0.774788] RDX: ffffffffffffe962 RSI: ffffbc8fc00866ad RDI: ffff9b1fc7c5b367
>>>>[ 0.774788] RBP: ffff9b1c10ca7018 R08: ffffbc8fc0085fff R09: 8000000000000063
>>>>[ 0.774788] R10: 0000000000001000 R11: 000fffffffe00000 R12: 0000000000003367
>>>>[ 0.774788] R13: ffff9b1fcc47c010 R14: ffffbc8fc0085000 R15: 0000000000000002
>>>>[ 0.774788] FS: 0000000000000000(0000) GS:ffff9b1fce200000(0000) knlGS:0000000000000000
>>>>[ 0.774788] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>>[ 0.774788] CR2: ffffbc8fc00866ad CR3: 000000029f60a001 CR4: 00000000003606f0
>>>>[ 0.774788] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>>>[ 0.774788] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>>>>[ 0.774788] Call Trace:
>>>>[ 0.774788] tpm_read_log_efi+0x156/0x1a0
>>>>[ 0.774788] tpm_bios_log_setup+0xc8/0x190
>>>>[ 0.774788] tpm_chip_register+0x50/0x1c0
>>>>[ 0.774788] tpm_tis_core_init.cold.9+0x28c/0x466
>>>>[ 0.774788] tpm_tis_plat_probe+0xcc/0xea
>>>>[ 0.774788] platform_drv_probe+0x35/0x80
>>>>[ 0.774788] really_probe+0xef/0x390
>>>>[ 0.774788] driver_probe_device+0xb4/0x100
>>>>[ 0.774788] device_driver_attach+0x4f/0x60
>>>>[ 0.774788] __driver_attach+0x86/0x140
>>>>[ 0.774788] ? device_driver_attach+0x60/0x60
>>>>[ 0.774788] bus_for_each_dev+0x76/0xc0
>>>>[ 0.774788] ? klist_add_tail+0x3b/0x70
>>>>[ 0.774788] bus_add_driver+0x14a/0x1e0
>>>>[ 0.774788] ? tpm_init+0xea/0xea
>>>>[ 0.774788] ? do_early_param+0x8e/0x8e
>>>>[ 0.774788] driver_register+0x6b/0xb0
>>>>[ 0.774788] ? tpm_init+0xea/0xea
>>>>[ 0.774788] init_tis+0x86/0xd8
>>>>[ 0.774788] ? do_early_param+0x8e/0x8e
>>>>[ 0.774788] ? driver_register+0x94/0xb0
>>>>[ 0.774788] do_one_initcall+0x46/0x1e4
>>>>[ 0.774788] ? do_early_param+0x8e/0x8e
>>>>[ 0.774788] kernel_init_freeable+0x199/0x242
>>>>[ 0.774788] ? rest_init+0xaa/0xaa
>>>>[ 0.774788] kernel_init+0xa/0x106
>>>>[ 0.774788] ret_from_fork+0x35/0x40
>>>>[ 0.774788] Modules linked in:
>>>>[ 0.774788] CR2: ffffbc8fc00866ad
>>>>[ 0.774788] ---[ end trace 42930799f8d6eaea ]---
>>>>[ 0.774788] RIP: 0010:memcpy_erms+0x6/0x10
>>>>[ 0.774788] Code: 90 90 90 90 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe
>>>>[ 0.774788] RSP: 0000:ffffbc8fc0073b30 EFLAGS: 00010286
>>>>[ 0.774788] RAX: ffff9b1fc7c5b367 RBX: ffff9b1fc8390000 RCX: ffffffffffffe962
>>>>[ 0.774788] RDX: ffffffffffffe962 RSI: ffffbc8fc00866ad RDI: ffff9b1fc7c5b367
>>>>[ 0.774788] RBP: ffff9b1c10ca7018 R08: ffffbc8fc0085fff R09: 8000000000000063
>>>>[ 0.774788] R10: 0000000000001000 R11: 000fffffffe00000 R12: 0000000000003367
>>>>[ 0.774788] R13: ffff9b1fcc47c010 R14: ffffbc8fc0085000 R15: 0000000000000002
>>>>[ 0.774788] FS: 0000000000000000(0000) GS:ffff9b1fce200000(0000) knlGS:0000000000000000
>>>>[ 0.774788] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>>>[ 0.774788] CR2: ffffbc8fc00866ad CR3: 000000029f60a001 CR4: 00000000003606f0
>>>>[ 0.774788] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>>>>[ 0.774788] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>>>>[ 0.774788] Kernel panic - not syncing: Fatal exception
>>>>[ 0.774788] Kernel Offset: 0x1d000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
>>>>[ 0.774788] ---[ end Kernel panic - not syncing: Fatal exception ]---
>>
>>I finally was able to get a laptop model where this is being seen. efi_tpm_final_log_size is -1, which I'm guessing is coming from
>>tpm2_calc_event_log_size, and the sanity check in tpm_read_log_efi is checking if efi_tpm_final_log_size == 0. Building a test
>>kernel really quick to verify that tpm2_calc_event_log_size is where it originates, but I imagine there should be a check of tbl_size
>>after tpm2_calc_event_log_size call in efi_tpm_eventlog_init?
>
>Continuing to investigate, it is getting -1 back from tpm2_calc_event_log_size:
>
>[ 0.000000] efi_tpm_eventlog_init: final_tbl->nr_events = 52
>[ 0.000000] tpm2_calc_event_log_size: count: 52 event_size: 113
>[ 0.000000] tpm2_calc_event_log_size: count: 51 event_size: 93
>[ 0.000000] tpm2_calc_event_log_size: count: 50 event_size: 118
>[ 0.000000] tpm2_calc_event_log_size: count: 49 event_size: 123
>[ 0.000000] tpm2_calc_event_log_size: count: 48 event_size: 86
>[ 0.000000] tpm2_calc_event_log_size: count: 47 event_size: 161
>[ 0.000000] tpm2_calc_event_log_size: count: 46 event_size: 93
>[ 0.000000] tpm2_calc_event_log_size: count: 45 event_size: 106
>[ 0.000000] tpm2_calc_event_log_size: count: 44 event_size: 108
>[ 0.000000] tpm2_calc_event_log_size: count: 43 event_size: 86
>[ 0.000000] tpm2_calc_event_log_size: count: 42 event_size: 105
>[ 0.000000] tpm2_calc_event_log_size: count: 41 event_size: 93
>[ 0.000000] tpm2_calc_event_log_size: count: 40 event_size: 104
>[ 0.000000] tpm2_calc_event_log_size: count: 39 event_size: 95
>[ 0.000000] tpm2_calc_event_log_size: count: 38 event_size: 99
>[ 0.000000] tpm2_calc_event_log_size: count: 37 event_size: 99
>[ 0.000000] tpm2_calc_event_log_size: count: 36 event_size: 100
>[ 0.000000] tpm2_calc_event_log_size: count: 35 event_size: 100
>[ 0.000000] tpm2_calc_event_log_size: count: 34 event_size: 91
>[ 0.000000] tpm2_calc_event_log_size: count: 33 event_size: 91
>[ 0.000000] tpm2_calc_event_log_size: count: 32 event_size: 100
>[ 0.000000] tpm2_calc_event_log_size: count: 31 event_size: 122
>[ 0.000000] tpm2_calc_event_log_size: count: 30 event_size: 93
>[ 0.000000] tpm2_calc_event_log_size: count: 29 event_size: 86
>[ 0.000000] tpm2_calc_event_log_size: count: 28 event_size: 95
>[ 0.000000] tpm2_calc_event_log_size: count: 27 event_size: 119
>[ 0.000000] tpm2_calc_event_log_size: count: 26 event_size: 97
>[ 0.000000] tpm2_calc_event_log_size: count: 25 event_size: 92
>[ 0.000000] tpm2_calc_event_log_size: count: 24 event_size: 93
>[ 0.000000] tpm2_calc_event_log_size: count: 23 event_size: 158
>[ 0.000000] tpm2_calc_event_log_size: count: 22 event_size: 97
>[ 0.000000] tpm2_calc_event_log_size: count: 21 event_size: 92
>[ 0.000000] tpm2_calc_event_log_size: count: 20 event_size: 93
>[ 0.000000] tpm2_calc_event_log_size: count: 19 event_size: 131
>[ 0.000000] tpm2_calc_event_log_size: count: 18 event_size: 95
>[ 0.000000] tpm2_calc_event_log_size: count: 17 event_size: 88
>[ 0.000000] tpm2_calc_event_log_size: count: 16 event_size: 118
>[ 0.000000] tpm2_calc_event_log_size: count: 15 event_size: 90
>[ 0.000000] tpm2_calc_event_log_size: count: 14 event_size: 136
>[ 0.000000] tpm2_calc_event_log_size: count: 13 event_size: 0
>[ 0.000000] efi_tpm_eventlog_init: tpm2_calc_event_log_size returned: -1
>...
>[ 1.282313] tpm_read_log_efi: efi_tpm_final_log_size is negative value: -1 (ffffffff)
>
>Then it will also subtract log_tbl->final_events_preboot_size, and
>this value gets passed to memcpy as the number of bytes to copy.
>
>Is this comment correct for __calc_tpm2_event_size?
>
>"Return: size of the event on success, <0 on failure"
>
>There are a number of spots where it will set size to 0. It looks like the
>only way it could potentially be less than 0 is where it does:
>
>size = marker - marker_start;
Am I reading the spec correctly that the event types should have values in the range 0x80000000-0x800000ff?
If that is the case it looks like only the first event has a valid type, all the rest have 0xd.
The TPM specifications list many valid event values, but 0xd was
EV_IPL in the TPM1.2 specification[0].
This has been deprecated in the PC Client Platform Firmware Profile
Specification for TPM2.0[1].
Shim and grub at this moment do indeed log values under this event ID.
[0]: https://trustedcomputinggroup.org/wp-content/uploads/PC-Client-Implementation-for-BIOS.pdf
[1]: https://trustedcomputinggroup.org/wp-content/uploads/TCG_PCClientSpecPlat_TPM_2p0_1p04_pub.pdf
Looking at it some more this afternoon it fails to parse the event
because it can't find the hash algorithm id from the event in the
TCG_EfiSpecIdEventAlgorithmSize array.
