If __calc_tpm2_event_size fails to parse an event it will return 0,
resulting tpm2_calc_event_log_size returning -1. Currently there is
no check of this return value, and efi_tpm_final_log_size can end up
being set to this negative value resulting in a panic like the
the one given below.
Also __calc_tpm2_event_size returns a size of 0 when it fails
to parse an event, so update function documentation to reflect this.
[ 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 ]---
The root cause of the issue that caused the failure of event parsing
in this case is resolved by Peter Jone's patchset dealing with large
event logs where crossing over a page boundary causes the page with
the event count to be unmapped.
Fixes: c46f3405692de ("tpm: Reserve the TPM final events table")
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Matthew Garrett <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jerry Snitselaar <[email protected]>
---
v3: rebase on top of Peter Jone's patchset
v2: added FW_BUG to pr_err, and renamed label to out_calc.
Updated doc comment for __calc_tpm2_event_size.
drivers/firmware/efi/tpm.c | 9 ++++++++-
include/linux/tpm_eventlog.h | 2 +-
2 files changed, 9 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
index b9ae5c6f9b9c..703469c1ab8e 100644
--- a/drivers/firmware/efi/tpm.c
+++ b/drivers/firmware/efi/tpm.c
@@ -85,11 +85,18 @@ int __init efi_tpm_eventlog_init(void)
final_tbl->nr_events,
log_tbl->log);
}
+
+ if (tbl_size < 0) {
+ pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n");
+ goto out_calc;
+ }
+
memblock_reserve((unsigned long)final_tbl,
tbl_size + sizeof(*final_tbl));
- early_memunmap(final_tbl, sizeof(*final_tbl));
efi_tpm_final_log_size = tbl_size;
+out_calc:
+ early_memunmap(final_tbl, sizeof(*final_tbl));
out:
early_memunmap(log_tbl, sizeof(*log_tbl));
return ret;
diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h
index 12584b69a3f3..2dfdd63ac034 100644
--- a/include/linux/tpm_eventlog.h
+++ b/include/linux/tpm_eventlog.h
@@ -152,7 +152,7 @@ struct tcg_algorithm_info {
* total. Once we've done this we know the offset of the data length field,
* and can calculate the total size of the event.
*
- * Return: size of the event on success, <0 on failure
+ * Return: size of the event on success, 0 on failure
*/
static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
--
2.23.0
On Wed, 25 Sep 2019 at 19:27, Jerry Snitselaar <[email protected]> wrote:
>
> If __calc_tpm2_event_size fails to parse an event it will return 0,
> resulting tpm2_calc_event_log_size returning -1. Currently there is
> no check of this return value, and efi_tpm_final_log_size can end up
> being set to this negative value resulting in a panic like the
> the one given below.
>
> Also __calc_tpm2_event_size returns a size of 0 when it fails
> to parse an event, so update function documentation to reflect this.
>
...
>
> The root cause of the issue that caused the failure of event parsing
> in this case is resolved by Peter Jone's patchset dealing with large
> event logs where crossing over a page boundary causes the page with
> the event count to be unmapped.
>
> Fixes: c46f3405692de ("tpm: Reserve the TPM final events table")
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: Matthew Garrett <[email protected]>
> Cc: Ard Biesheuvel <[email protected]>
> Cc: Jarkko Sakkinen <[email protected]>
> Signed-off-by: Jerry Snitselaar <[email protected]>
Thanks Jerry, I have queued this in the efi/urgent branch.
> ---
> v3: rebase on top of Peter Jone's patchset
> v2: added FW_BUG to pr_err, and renamed label to out_calc.
> Updated doc comment for __calc_tpm2_event_size.
>
> drivers/firmware/efi/tpm.c | 9 ++++++++-
> include/linux/tpm_eventlog.h | 2 +-
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c
> index b9ae5c6f9b9c..703469c1ab8e 100644
> --- a/drivers/firmware/efi/tpm.c
> +++ b/drivers/firmware/efi/tpm.c
> @@ -85,11 +85,18 @@ int __init efi_tpm_eventlog_init(void)
> final_tbl->nr_events,
> log_tbl->log);
> }
> +
> + if (tbl_size < 0) {
> + pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n");
> + goto out_calc;
> + }
> +
> memblock_reserve((unsigned long)final_tbl,
> tbl_size + sizeof(*final_tbl));
> - early_memunmap(final_tbl, sizeof(*final_tbl));
> efi_tpm_final_log_size = tbl_size;
>
> +out_calc:
> + early_memunmap(final_tbl, sizeof(*final_tbl));
> out:
> early_memunmap(log_tbl, sizeof(*log_tbl));
> return ret;
> diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h
> index 12584b69a3f3..2dfdd63ac034 100644
> --- a/include/linux/tpm_eventlog.h
> +++ b/include/linux/tpm_eventlog.h
> @@ -152,7 +152,7 @@ struct tcg_algorithm_info {
> * total. Once we've done this we know the offset of the data length field,
> * and can calculate the total size of the event.
> *
> - * Return: size of the event on success, <0 on failure
> + * Return: size of the event on success, 0 on failure
> */
>
> static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
> --
> 2.23.0
>
On Wed, Sep 25, 2019 at 10:27:05AM -0700, Jerry Snitselaar wrote:
> If __calc_tpm2_event_size fails to parse an event it will return 0,
> resulting tpm2_calc_event_log_size returning -1. Currently there is
> no check of this return value, and efi_tpm_final_log_size can end up
> being set to this negative value resulting in a panic like the
> the one given below.
>
> Also __calc_tpm2_event_size returns a size of 0 when it fails
> to parse an event, so update function documentation to reflect this.
>
> [ 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 ]---
>
> The root cause of the issue that caused the failure of event parsing
> in this case is resolved by Peter Jone's patchset dealing with large
> event logs where crossing over a page boundary causes the page with
> the event count to be unmapped.
>
> Fixes: c46f3405692de ("tpm: Reserve the TPM final events table")
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: Matthew Garrett <[email protected]>
> Cc: Ard Biesheuvel <[email protected]>
> Cc: Jarkko Sakkinen <[email protected]>
> Signed-off-by: Jerry Snitselaar <[email protected]>
Reviewed-by: <[email protected]>
/Jarkko