From: Stefan Berger stefanb@linux.ibm.com
commit 48cff270b037022e37835d93361646205ca25101 upstream.
When tpm_read_log_efi is called multiple times, which happens when one loads and unloads a TPM2 driver multiple times, then the global variable efi_tpm_final_log_size will at some point become a negative number due to the subtraction of final_events_preboot_size occurring each time. Use a local variable to avoid this integer underflow.
The following issue is now resolved:
Mar 8 15:35:12 hibinst kernel: Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Mar 8 15:35:12 hibinst kernel: Workqueue: tpm-vtpm vtpm_proxy_work [tpm_vtpm_proxy] Mar 8 15:35:12 hibinst kernel: RIP: 0010:__memcpy+0x12/0x20 Mar 8 15:35:12 hibinst kernel: Code: 00 b8 01 00 00 00 85 d2 74 0a c7 05 44 7b ef 00 0f 00 00 00 c3 cc cc cc 66 66 90 66 90 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 Mar 8 15:35:12 hibinst kernel: RSP: 0018:ffff9ac4c0fcfde0 EFLAGS: 00010206 Mar 8 15:35:12 hibinst kernel: RAX: ffff88f878cefed5 RBX: ffff88f878ce9000 RCX: 1ffffffffffffe0f Mar 8 15:35:12 hibinst kernel: RDX: 0000000000000003 RSI: ffff9ac4c003bff9 RDI: ffff88f878cf0e4d Mar 8 15:35:12 hibinst kernel: RBP: ffff9ac4c003b000 R08: 0000000000001000 R09: 000000007e9d6073 Mar 8 15:35:12 hibinst kernel: R10: ffff9ac4c003b000 R11: ffff88f879ad3500 R12: 0000000000000ed5 Mar 8 15:35:12 hibinst kernel: R13: ffff88f878ce9760 R14: 0000000000000002 R15: ffff88f77de7f018 Mar 8 15:35:12 hibinst kernel: FS: 0000000000000000(0000) GS:ffff88f87bd00000(0000) knlGS:0000000000000000 Mar 8 15:35:12 hibinst kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Mar 8 15:35:12 hibinst kernel: CR2: ffff9ac4c003c000 CR3: 00000001785a6004 CR4: 0000000000060ee0 Mar 8 15:35:12 hibinst kernel: Call Trace: Mar 8 15:35:12 hibinst kernel: tpm_read_log_efi+0x152/0x1a7 Mar 8 15:35:12 hibinst kernel: tpm_bios_log_setup+0xc8/0x1c0 Mar 8 15:35:12 hibinst kernel: tpm_chip_register+0x8f/0x260 Mar 8 15:35:12 hibinst kernel: vtpm_proxy_work+0x16/0x60 [tpm_vtpm_proxy] Mar 8 15:35:12 hibinst kernel: process_one_work+0x1b4/0x370 Mar 8 15:35:12 hibinst kernel: worker_thread+0x53/0x3e0 Mar 8 15:35:12 hibinst kernel: ? process_one_work+0x370/0x370
Cc: stable@vger.kernel.org Fixes: 166a2809d65b ("tpm: Don't duplicate events from the final event log in the TCG2 log") Signed-off-by: Stefan Berger stefanb@linux.ibm.com Reviewed-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Jarkko Sakkinen jarkko@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/tpm/eventlog/efi.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-)
--- a/drivers/char/tpm/eventlog/efi.c +++ b/drivers/char/tpm/eventlog/efi.c @@ -17,6 +17,7 @@ int tpm_read_log_efi(struct tpm_chip *ch {
struct efi_tcg2_final_events_table *final_tbl = NULL; + int final_events_log_size = efi_tpm_final_log_size; struct linux_efi_tpm_eventlog *log_tbl; struct tpm_bios_log *log; u32 log_size; @@ -66,12 +67,12 @@ int tpm_read_log_efi(struct tpm_chip *ch ret = tpm_log_version;
if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR || - efi_tpm_final_log_size == 0 || + final_events_log_size == 0 || tpm_log_version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) goto out;
final_tbl = memremap(efi.tpm_final_log, - sizeof(*final_tbl) + efi_tpm_final_log_size, + sizeof(*final_tbl) + final_events_log_size, MEMREMAP_WB); if (!final_tbl) { pr_err("Could not map UEFI TPM final log\n"); @@ -80,10 +81,18 @@ int tpm_read_log_efi(struct tpm_chip *ch goto out; }
- efi_tpm_final_log_size -= log_tbl->final_events_preboot_size; + /* + * The 'final events log' size excludes the 'final events preboot log' + * at its beginning. + */ + final_events_log_size -= log_tbl->final_events_preboot_size;
+ /* + * Allocate memory for the 'combined log' where we will append the + * 'final events log' to. + */ tmp = krealloc(log->bios_event_log, - log_size + efi_tpm_final_log_size, + log_size + final_events_log_size, GFP_KERNEL); if (!tmp) { kfree(log->bios_event_log); @@ -94,15 +103,19 @@ int tpm_read_log_efi(struct tpm_chip *ch log->bios_event_log = tmp;
/* - * Copy any of the final events log that didn't also end up in the - * main log. Events can be logged in both if events are generated + * Append any of the 'final events log' that didn't also end up in the + * 'main log'. Events can be logged in both if events are generated * between GetEventLog() and ExitBootServices(). */ memcpy((void *)log->bios_event_log + log_size, final_tbl->events + log_tbl->final_events_preboot_size, - efi_tpm_final_log_size); + final_events_log_size); + /* + * The size of the 'combined log' is the size of the 'main log' plus + * the size of the 'final events log'. + */ log->bios_event_log_end = log->bios_event_log + - log_size + efi_tpm_final_log_size; + log_size + final_events_log_size;
out: memunmap(final_tbl);