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path: root/drivers/char/tpm/eventlog/efi.c
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2023-02-13tpm: Use managed allocation for bios event logEddie James1-6/+7
Since the bios event log is freed in the device release function, let devres handle the deallocation. This will allow other memory allocation/mapping functions to be used for the bios event log. Signed-off-by: Eddie James <eajames@linux.ibm.com> Tested-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2021-04-14tpm: efi: Use local variable for calculating final log sizeStefan Berger1-8/+21
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>
2020-11-06tpm: efi: Don't create binary_bios_measurements file for an empty logTyler Hicks1-0/+5
Mimic the pre-existing ACPI and Device Tree event log behavior by not creating the binary_bios_measurements file when the EFI TPM event log is empty. This fixes the following NULL pointer dereference that can occur when reading /sys/kernel/security/tpm0/binary_bios_measurements after the kernel received an empty event log from the firmware: BUG: kernel NULL pointer dereference, address: 000000000000002c #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 2 PID: 3932 Comm: fwupdtpmevlog Not tainted 5.9.0-00003-g629990edad62 #17 Hardware name: LENOVO 20LCS03L00/20LCS03L00, BIOS N27ET38W (1.24 ) 11/28/2019 RIP: 0010:tpm2_bios_measurements_start+0x3a/0x550 Code: 54 53 48 83 ec 68 48 8b 57 70 48 8b 1e 65 48 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 48 8b 82 c0 06 00 00 48 8b 8a c8 06 00 00 <44> 8b 60 1c 48 89 4d a0 4c 89 e2 49 83 c4 20 48 83 fb 00 75 2a 49 RSP: 0018:ffffa9c901203db0 EFLAGS: 00010246 RAX: 0000000000000010 RBX: 0000000000000000 RCX: 0000000000000010 RDX: ffff8ba1eb99c000 RSI: ffff8ba1e4ce8280 RDI: ffff8ba1e4ce8258 RBP: ffffa9c901203e40 R08: ffffa9c901203dd8 R09: ffff8ba1ec443300 R10: ffffa9c901203e50 R11: 0000000000000000 R12: ffff8ba1e4ce8280 R13: ffffa9c901203ef0 R14: ffffa9c901203ef0 R15: ffff8ba1e4ce8258 FS: 00007f6595460880(0000) GS:ffff8ba1ef880000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000002c CR3: 00000007d8d18003 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? __kmalloc_node+0x113/0x320 ? kvmalloc_node+0x31/0x80 seq_read+0x94/0x420 vfs_read+0xa7/0x190 ksys_read+0xa7/0xe0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x37/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9 In this situation, the bios_event_log pointer in the tpm_bios_log struct was not NULL but was equal to the ZERO_SIZE_PTR (0x10) value. This was due to the following kmemdup() in tpm_read_log_efi(): int tpm_read_log_efi(struct tpm_chip *chip) { ... /* malloc EventLog space */ log->bios_event_log = kmemdup(log_tbl->log, log_size, GFP_KERNEL); if (!log->bios_event_log) { ret = -ENOMEM; goto out; } ... } When log_size is zero, due to an empty event log from firmware, ZERO_SIZE_PTR is returned from kmemdup(). Upon a read of the binary_bios_measurements file, the tpm2_bios_measurements_start() function does not perform a ZERO_OR_NULL_PTR() check on the bios_event_log pointer before dereferencing it. Rather than add a ZERO_OR_NULL_PTR() check in functions that make use of the bios_event_log pointer, simply avoid creating the binary_bios_measurements_file as is done in other event log retrieval backends. Explicitly ignore all of the events in the final event log when the main event log is empty. The list of events in the final event log cannot be accurately parsed without referring to the first event in the main event log (the event log header) so the final event log is useless in such a situation. Fixes: 58cc1e4faf10 ("tpm: parse TPM event logs based on EFI table") Link: https://lore.kernel.org/linux-integrity/E1FDCCCB-CA51-4AEE-AC83-9CDE995EAE52@canonical.com/ Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Reported-by: Kenneth R. Crudup <kenny@panix.com> Reported-by: Mimi Zohar <zohar@linux.ibm.com> Cc: ThiƩbaud Weksteen <tweek@google.com> Cc: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2019-06-24tpm: Don't duplicate events from the final event log in the TCG2 logMatthew Garrett1-1/+10
After the first call to GetEventLog() on UEFI systems using the TCG2 crypto agile log format, any further log events (other than those triggered by ExitBootServices()) will be logged in both the main log and also in the Final Events Log. While the kernel only calls GetEventLog() immediately before ExitBootServices(), we can't control whether earlier parts of the boot process have done so. This will result in log entries that exist in both logs, and so the current approach of simply appending the Final Event Log to the main log will result in events being duplicated. We can avoid this problem by looking at the size of the Final Event Log just before we call ExitBootServices() and exporting this to the main kernel. The kernel can then skip over all events that occured before ExitBootServices() and only append events that were not also logged to the main log. Signed-off-by: Matthew Garrett <mjg59@google.com> Reported-by: Joe Richey <joerichey@google.com> Suggested-by: Joe Richey <joerichey@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2019-06-24tpm: Append the final event log to the TPM event logMatthew Garrett1-7/+43
Any events that are logged after GetEventsLog() is called are logged to the EFI Final Events table. These events are defined as being in the crypto agile log format, so we can just append them directly to the existing log if it's in the same format. In theory we can also construct old-style SHA1 log entries for devices that only return logs in that format, but EDK2 doesn't generate the final event log in that case so it doesn't seem worth it at the moment. Signed-off-by: Matthew Garrett <mjg59@google.com> Reviewed-by: Bartosz Szczepanek <bsz@semihalf.com> Tested-by: Bartosz Szczepanek <bsz@semihalf.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner1-6/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-14tpm: replace kmalloc() + memcpy() with kmemdup()Ji-Hun Kim1-2/+1
Use kmemdup rather than duplicating its implementation. Signed-off-by: Ji-Hun Kim <ji_hun.kim@samsung.com> Reviewed-by: James Morris <james.morris@microsoft.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkine@linux.intel.com>
2018-05-09tpm: Move eventlog declarations to its own headerThiebaud Weksteen1-0/+1
Reduce the size of tpm.h by moving eventlog declarations to a separate header. Signed-off-by: Thiebaud Weksteen <tweek@google.com> Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-05-09tpm: Move eventlog files to a subdirectoryThiebaud Weksteen1-0/+66
Signed-off-by: Thiebaud Weksteen <tweek@google.com> Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>