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path: root/drivers/char/tpm/eventlog/tpm2.c
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* tpm: eventlog: Replace zero-length array with flexible-array memberGustavo A. R. Silva2020-05-221-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. Also, the following issue shows up due to the flexible-array member having incomplete type[4]: drivers/char/tpm/eventlog/tpm2.c: In function ‘tpm2_bios_measurements_start’: drivers/char/tpm/eventlog/tpm2.c:54:46: error: invalid application of ‘sizeof’ to incomplete type ‘u8[]’ {aka ‘unsigned char[]’} 54 | size = sizeof(struct tcg_pcr_event) - sizeof(event_header->event) | ^ drivers/char/tpm/eventlog/tpm2.c: In function ‘tpm2_bios_measurements_next’: drivers/char/tpm/eventlog/tpm2.c:102:10: error: invalid application of ‘sizeof’ to incomplete type ‘u8[]’ {aka ‘unsigned char[]’} 102 | sizeof(event_header->event) + event_header->event_size; | ^ drivers/char/tpm/eventlog/tpm2.c: In function ‘tpm2_binary_bios_measurements_show’: drivers/char/tpm/eventlog/tpm2.c:140:10: error: invalid application of ‘sizeof’ to incomplete type ‘u8[]’ {aka ‘unsigned char[]’} 140 | sizeof(event_header->event) + event_header->event_size; | ^ scripts/Makefile.build:266: recipe for target 'drivers/char/tpm/eventlog/tpm2.o' failed make[3]: *** [drivers/char/tpm/eventlog/tpm2.o] Error 1 As mentioned above: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] As in "sizeof(event_header->event) always evaluated to 0, so removing it has no effect". Lastly, make use of the struct_size() helper to deal with the flexible array member and its host structure. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") [4] https://github.com/KSPP/linux/issues/43 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
* tpm: tpm2_bios_measurements_next should increase position indexVasily Averin2020-03-131-1/+1
| | | | | | | | | | | | | | | | | | If .next function does not change position index, following .show function will repeat output related to current position index. For /sys/kernel/security/tpm0/binary_bios_measurements: 1) read after lseek beyound end of file generates whole last line. 2) read after lseek to middle of last line generates expected end of last line and unexpected whole last line once again. Cc: stable@vger.kernel.org # 4.19.x Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...") Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
* tpm: Reserve the TPM final events tableMatthew Garrett2019-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | UEFI systems provide a boot services protocol for obtaining the TPM event log, but this is unusable after ExitBootServices() is called. Unfortunately ExitBootServices() itself triggers additional TPM events that then can't be obtained using this protocol. The platform provides a mechanism for the OS to obtain these events by recording them to a separate UEFI configuration table which the OS can then map. Unfortunately this table isn't self describing in terms of providing its length, so we need to parse the events inside it to figure out how long it is. Since the table isn't mapped at this point, we need to extend the length calculation function to be able to map the event as it goes along. (Fixes by Bartosz Szczepanek <bsz@semihalf.com>) Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> 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>
* tpm: Abstract crypto agile event size calculationsMatthew Garrett2019-06-241-46/+1
| | | | | | | | | | | | | | We need to calculate the size of crypto agile events in multiple locations, including in the EFI boot stub. The easiest way to do this is to put it in a header file as an inline and leave a wrapper to ensure we don't end up with multiple copies of it embedded in the existing code. 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>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152Thomas Gleixner2019-05-301-5/+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>
* tpm: Fix the type of the return value in calc_tpm2_event_size()Yue Haibing2019-04-081-2/+2
| | | | | | | | | | | | | | calc_tpm2_event_size() has an invalid signature because it returns a 'size_t' where as its signature says that it returns 'int'. Cc: <stable@vger.kernel.org> Fixes: 4d23cc323cdb ("tpm: add securityfs support for TPM 2.0 firmware event log") Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: James Morris <james.morris@microsoft.com>
* tpm: add _head suffix to tcg_efi_specid_event and tcg_pcr_event2Roberto Sassu2019-02-131-6/+6
| | | | | | | | | | | | | | | | | | | | TCG defines two structures, TCG_EfiSpecIDEventStruct and TCG_PCR_EVENT2, which contain variable-sized arrays in the middle of the definition. Since these structures are not suitable for type casting, this patch removes structure members after the variable-sized arrays and adds the _head suffix to the structure name, to indicate that the renamed structures do not contain all fields defined by TCG. Lastly, given that variable-sized arrays are now in the last position, and given that the size of the arrays cannot be determined in advance, this patch also sets the size of those arrays to zero and removes the definition of TPM2_ACTIVE_PCR_BANKS. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Tested-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
* tpm: Move eventlog declarations to its own headerThiebaud Weksteen2018-05-091-0/+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>
* tpm: Move eventlog files to a subdirectoryThiebaud Weksteen2018-05-091-0/+209
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>