| Message ID | 20190503222523.6294-1-prsriva02@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Kexec cmdline bufffer measure | expand |
On Fri, 2019-05-03 at 15:25 -0700, Prakhar Srivastava wrote: > From: Prakhar Srivastava <prsriva02@gmail.com> > > For Kexec scenario(kexec_file_load) cmdline args are passed to the > next kerenel. These cmldine args used to load the next kernel can > have undesired/unwanted configs. To guard against any unwanted cmdline > args being passed to the next kernel. The current kernel should measure > the cmdline args to the next kernel, the same takes place in the EFI > bootloader. Thus on kexec the boot_aggregate does not change. The boot command line is calculated and added to the current running kernel's measurement list. On a soft reboot like kexec, the PCRs are not reset to zero. Refer to commit 94c3aac567a9 ("ima: on soft reboot, restore the measurement list") patch description. > Currently the cmdline args are not measured, this changeset adds a new > ima and LSM hook for buffer measure and calls into the same to measure > the cmdline args passed to the next kernel.The cdmline args meassured > can then be used as an attestation criteria. Please update this paragraph to reflect the current patch set. > > The ima logs need to injected into the next kernel, which will be followed > up by other patchsets. The log isn't "injected" into the next kernel, but needs to be carried over, as described in the above referenced commit. Mimi
From: Prakhar Srivastava <prsriva02@gmail.com> For Kexec scenario(kexec_file_load) cmdline args are passed to the next kerenel. These cmldine args used to load the next kernel can have undesired/unwanted configs. To guard against any unwanted cmdline args being passed to the next kernel. The current kernel should measure the cmdline args to the next kernel, the same takes place in the EFI bootloader. Thus on kexec the boot_aggregate does not change. Currently the cmdline args are not measured, this changeset adds a new ima and LSM hook for buffer measure and calls into the same to measure the cmdline args passed to the next kernel.The cdmline args meassured can then be used as an attestation criteria. The ima logs need to injected into the next kernel, which will be followed up by other patchsets. Changelog: v4: - per feedback from LSM community, removed the LSM hook and renamed the IMA policy to KEXEC_CMDLINE[Suggested by: Mimi Zohar] v3: (rebase changes to next-general) - Add policy checks for buffer[suggested by Mimi Zohar] - use the IMA_XATTR to add buffer - Add kexec_cmdline used for kexec file load - Add an LSM hook to allow usage by other LSM.[suggestd by Mimi Zohar] v2: - Add policy checks for buffer[suggested by Mimi Zohar] - Add an LSM hook to allow usage by other LSM.[suggestd by Mimi Zohar] - use the IMA_XATTR to add buffer instead of sig template v1: -Add kconfigs to control the ima_buffer_check -measure the cmdline args suffixed with the kernel file name -add the buffer to the template sig field. Prakhar Srivastava (5): added a new ima policy func buffer_check, and ima hook to measure the buffer hash into ima add the buffer to the xattr add kexec_cmdline used to ima added LSM hook to call ima_buffer_check removed the LSM hook made available, and renamed the ima_policy to be KEXEC_CMDLINE Documentation/ABI/testing/ima_policy | 1 + include/linux/ima.h | 3 + include/linux/security.h | 2 + kernel/kexec_core.c | 2 +- kernel/kexec_file.c | 4 + kernel/kexec_internal.h | 4 +- security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_api.c | 1 + security/integrity/ima/ima_main.c | 115 ++++++++++++++++++++++ security/integrity/ima/ima_policy.c | 8 ++ security/integrity/ima/ima_template_lib.c | 3 +- security/integrity/integrity.h | 1 + 12 files changed, 142 insertions(+), 3 deletions(-)