This patch defines a new value for the 'ima_show_type' enumerator (IMA_SHOW_BINARY_NO_FIELD_LEN) to prevent that the field length is transmitted through the 'binary_runtime_measurements' interface for the digest field of the 'ima' template.
Signed-off-by: Roberto Sassu <[email protected]> Signed-off-by: Mimi Zohar <[email protected]> --- security/integrity/ima/ima.h | 3 ++- security/integrity/ima/ima_fs.c | 14 +++++++++++--- security/integrity/ima/ima_template_lib.c | 6 +++++- 3 files changed, 18 insertions(+), 5 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index a21cf70..9636e17 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -26,7 +26,8 @@ #include "../integrity.h" -enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII }; +enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN, + IMA_SHOW_ASCII }; enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 }; /* digest size for IMA, fits SHA1 or MD5 */ diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index d47a7c8..db01125 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -120,6 +120,7 @@ static int ima_measurements_show(struct seq_file *m, void *v) struct ima_template_entry *e; int namelen; u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX; + bool is_ima_template = false; int i; /* get entry */ @@ -145,14 +146,21 @@ static int ima_measurements_show(struct seq_file *m, void *v) ima_putc(m, e->template_desc->name, namelen); /* 5th: template length (except for 'ima' template) */ - if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) + if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) + is_ima_template = true; + + if (!is_ima_template) ima_putc(m, &e->template_data_len, sizeof(e->template_data_len)); /* 6th: template specific data */ for (i = 0; i < e->template_desc->num_fields; i++) { - e->template_desc->fields[i]->field_show(m, IMA_SHOW_BINARY, - &e->template_data[i]); + enum ima_show_type show = IMA_SHOW_BINARY; + struct ima_template_field *field = e->template_desc->fields[i]; + + if (is_ima_template && strcmp(field->field_id, "d") == 0) + show = IMA_SHOW_BINARY_NO_FIELD_LEN; + field->field_show(m, show, &e->template_data[i]); } return 0; } diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index 6d01c69..1683bbf 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -109,9 +109,12 @@ static void ima_show_template_data_binary(struct seq_file *m, enum data_formats datafmt, struct ima_field_data *field_data) { - ima_putc(m, &field_data->len, sizeof(u32)); + if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) + ima_putc(m, &field_data->len, sizeof(u32)); + if (!field_data->len) return; + ima_putc(m, field_data->data, field_data->len); } @@ -125,6 +128,7 @@ static void ima_show_template_field_data(struct seq_file *m, ima_show_template_data_ascii(m, show, datafmt, field_data); break; case IMA_SHOW_BINARY: + case IMA_SHOW_BINARY_NO_FIELD_LEN: ima_show_template_data_binary(m, show, datafmt, field_data); break; default: -- 1.8.1.4
smime.p7s
Description: S/MIME cryptographic signature
