From: Roberto Sassu <roberto.sassu@huawei.com>
To: Prakhar Srivastava <prsriva02@gmail.com>,
<linux-integrity@vger.kernel.org>,
<inux-security-module@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Cc: <zohar@linux.ibm.com>, <ebiederm@xmission.com>,
<vgoyal@redhat.com>, <prsriva@microsoft.com>
Subject: Re: [PATCH 2/3 v5] add a new template field buf to contain the buffer
Date: Mon, 13 May 2019 15:48:49 +0200 [thread overview]
Message-ID: <45344b2f-d9ea-f7df-e45f-18037e2ba5ca@huawei.com> (raw)
In-Reply-To: <20190510223744.10154-3-prsriva02@gmail.com>
On 5/11/2019 12:37 AM, Prakhar Srivastava wrote:
> From: Prakhar Srivastava <prsriva02@gmail.com>
>
> The buffer(cmdline args) added to the ima log cannot be attested
> without having the actual buffer. Thus to make the measured buffer
> available to stroe/read a new ima temaplate (buf) is added.
Hi Prakhar
please fix the typos. More comments below.
> The cmdline args used for soft reboot can then be read and attested
> later.
>
> The patch adds a new template field buf to store/read the buffer
> used while measuring kexec_cmdline args in the
> [PATCH 1/2 v5]: "add a new ima hook and policy to measure the cmdline".
> Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
> ---
> security/integrity/ima/ima_main.c | 23 +++++++++++++++++++++++
> security/integrity/ima/ima_template.c | 2 ++
> security/integrity/ima/ima_template_lib.c | 21 +++++++++++++++++++++
> security/integrity/ima/ima_template_lib.h | 4 ++++
> security/integrity/integrity.h | 1 +
> 5 files changed, 51 insertions(+)
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 1d186bda25fe..ca12885ca241 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -605,10 +605,32 @@ static int process_buffer_measurement(const void *buf, int size,
> int pcr = CONFIG_IMA_MEASURE_PCR_IDX;
> int action = 0;
>
> + struct buffer_xattr {
> + enum evm_ima_xattr_type type;
> + u16 buf_length;
> + unsigned char buf[0];
> + };
> + struct buffer_xattr *buffer_event_data = NULL;
> + int alloc_length = 0;
> +
> action = ima_get_action(NULL, cred, secid, 0, KEXEC_CMDLINE, &pcr);
> if (!(action & IMA_AUDIT) && !(action & IMA_MEASURE))
> goto out;
>
> + alloc_length = sizeof(struct buffer_xattr) + size;
> + buffer_event_data = kzalloc(alloc_length, GFP_KERNEL);
> + if (!buffer_event_data) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + buffer_event_data->type = IMA_XATTR_BUFFER;
> + buffer_event_data->buf_length = size;
> + memcpy(buffer_event_data->buf, buf, size);
> +
> + event_data.xattr_value = (struct evm_ima_xattr_data *)buffer_event_data;
> + event_data.xattr_len = alloc_length;
I would prefer that you introduce two new fields in the ima_event_data
structure. You can initialize them directly with the parameters of
process_buffer_measurement(). ima_write_template_field_data() will make
a copy.
> +
> memset(iint, 0, sizeof(*iint));
> memset(&hash, 0, sizeof(hash));
>
> @@ -638,6 +660,7 @@ static int process_buffer_measurement(const void *buf, int size,
> }
>
> out:
> + kfree(buffer_event_data);
> return ret;
> }
>
> diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
> index b631b8bc7624..a76d1c04162a 100644
> --- a/security/integrity/ima/ima_template.c
> +++ b/security/integrity/ima/ima_template.c
> @@ -43,6 +43,8 @@ static const struct ima_template_field supported_fields[] = {
> .field_show = ima_show_template_string},
> {.field_id = "sig", .field_init = ima_eventsig_init,
> .field_show = ima_show_template_sig},
> + {.field_id = "buf", .field_init = ima_eventbuf_init,
> + .field_show = ima_show_template_buf},
Please update Documentation/security/IMA-templates.rst
Thanks
Roberto
> };
> #define MAX_TEMPLATE_NAME_LEN 15
>
> diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
> index 513b457ae900..95a827f42c18 100644
> --- a/security/integrity/ima/ima_template_lib.c
> +++ b/security/integrity/ima/ima_template_lib.c
> @@ -162,6 +162,11 @@ void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
> ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
> }
>
> +void ima_show_template_buf(struct seq_file *m, enum ima_show_type show,
> + struct ima_field_data *field_data)
> +{
> + ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
> +}
> /**
> * ima_parse_buf() - Parses lengths and data from an input buffer
> * @bufstartp: Buffer start address.
> @@ -389,3 +394,19 @@ int ima_eventsig_init(struct ima_event_data *event_data,
> return ima_write_template_field_data(xattr_value, event_data->xattr_len,
> DATA_FMT_HEX, field_data);
> }
> +
> +/*
> + * ima_eventbuf_init - include the buffer(kexec-cmldine) as part of the
> + * template data.
> + */
> +int ima_eventbuf_init(struct ima_event_data *event_data,
> + struct ima_field_data *field_data)
> +{
> + struct evm_ima_xattr_data *xattr_value = event_data->xattr_value;
> +
> + if ((!xattr_value) || (xattr_value->type != IMA_XATTR_BUFFER))
> + return 0;
> +
> + return ima_write_template_field_data(xattr_value, event_data->xattr_len,
> + DATA_FMT_HEX, field_data);
> +}
> diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
> index 6a3d8b831deb..12f1a8578b31 100644
> --- a/security/integrity/ima/ima_template_lib.h
> +++ b/security/integrity/ima/ima_template_lib.h
> @@ -29,6 +29,8 @@ void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
> struct ima_field_data *field_data);
> void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
> struct ima_field_data *field_data);
> +void ima_show_template_buf(struct seq_file *m, enum ima_show_type show,
> + struct ima_field_data *field_data);
> int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp,
> int maxfields, struct ima_field_data *fields, int *curfields,
> unsigned long *len_mask, int enforce_mask, char *bufname);
> @@ -42,4 +44,6 @@ int ima_eventname_ng_init(struct ima_event_data *event_data,
> struct ima_field_data *field_data);
> int ima_eventsig_init(struct ima_event_data *event_data,
> struct ima_field_data *field_data);
> +int ima_eventbuf_init(struct ima_event_data *event_data,
> + struct ima_field_data *field_data);
> #endif /* __LINUX_IMA_TEMPLATE_LIB_H */
> diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
> index 7de59f44cba3..14ef904f091d 100644
> --- a/security/integrity/integrity.h
> +++ b/security/integrity/integrity.h
> @@ -74,6 +74,7 @@ enum evm_ima_xattr_type {
> EVM_IMA_XATTR_DIGSIG,
> IMA_XATTR_DIGEST_NG,
> EVM_XATTR_PORTABLE_DIGSIG,
> + IMA_XATTR_BUFFER,
> IMA_XATTR_LAST
> };
>
>
--
HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063
Managing Director: Bo PENG, Jian LI, Yanli SHI
next prev parent reply other threads:[~2019-05-13 13:48 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-10 22:37 [PATCH 0/3 v5] Kexec cmdline bufffer measure Prakhar Srivastava
2019-05-10 22:37 ` [PATCH 1/3 v5] add a new ima hook and policy to measure the cmdline Prakhar Srivastava
2019-05-13 16:56 ` Mimi Zohar
2019-05-14 4:53 ` prakhar srivastava
2019-05-14 14:36 ` Mimi Zohar
2019-05-10 22:37 ` [PATCH 2/3 v5] add a new template field buf to contain the buffer Prakhar Srivastava
2019-05-13 13:48 ` Roberto Sassu [this message]
2019-05-14 5:07 ` prakhar srivastava
2019-05-14 13:22 ` Roberto Sassu
2019-05-17 23:32 ` prakhar srivastava
2019-05-20 12:18 ` Roberto Sassu
2019-05-10 22:37 ` [PATCH 3/3 v5] call ima_kexec_cmdline from kexec_file_load path Prakhar Srivastava
2019-05-14 14:46 ` Mimi Zohar
-- strict thread matches above, loose matches on Subject: below --
2019-05-10 22:32 [PATCH 0/3 v5] Kexec cmdline bufffer measure Prakhar Srivastava
2019-05-10 22:32 ` [PATCH 2/3 v5] add a new template field buf to contain the buffer Prakhar Srivastava
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=45344b2f-d9ea-f7df-e45f-18037e2ba5ca@huawei.com \
--to=roberto.sassu@huawei.com \
--cc=ebiederm@xmission.com \
--cc=inux-security-module@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=prsriva02@gmail.com \
--cc=prsriva@microsoft.com \
--cc=vgoyal@redhat.com \
--cc=zohar@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).