From: Joey Lee <JLee@suse.com>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Chun-Yi Lee <joeyli.kernel@gmail.com>,
Josh Boyer <jwboyer@fedoraproject.org>,
"Serge E . Hallyn" <serge@hallyn.com>,
"Nayna Jain" <nayna@linux.ibm.com>,
Mimi Zohar <zohar@linux.ibm.com>,
James Morris <jmorris@namei.org>,
David Howells <dhowells@redhat.com>,
linux-efi <linux-efi@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-security-module <linux-security-module@vger.kernel.org>
Subject: Re: [PATCH 2/2] efi: show error messages only when loading certificates is failed
Date: Fri, 13 Dec 2019 09:20:58 +0000 [thread overview]
Message-ID: <20191213092049.GW22409@linux-l9pv.suse> (raw)
In-Reply-To: <CAKv+Gu_2GTqKJNVpMEg4ic_3ACb5GJKAkgfFWoEdWqMN7pmwiA@mail.gmail.com>
Hi Ard,
On Fri, Dec 13, 2019 at 09:10:12AM +0000, Ard Biesheuvel wrote:
> On Fri, 13 Dec 2019 at 10:07, Lee, Chun-Yi <joeyli.kernel@gmail.com> wrote:
> >
> > When loading certificates list from EFI variables, the error
> > message and efi status code always be emitted to dmesg. It looks
> > ugly:
> >
> > [ 2.335031] Couldn't get size: 0x800000000000000e
> > [ 2.335032] Couldn't get UEFI MokListRT
> > [ 2.339985] Couldn't get size: 0x800000000000000e
> > [ 2.339987] Couldn't get UEFI dbx list
> >
> > This cosmetic patch moved the messages to the error handling code
> > path. And, it also shows the corresponding status string of status
> > code.
> >
>
> So what output do we get after applying this patch when those
> variables don't exist?
>
A "UEFI:xxxx list was not found" message will be exposed in dmesg
when kernel loglevel be set to debug. Otherwise there have no messages.
Thanks
Joey Lee
> > Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
> > ---
> > security/integrity/platform_certs/load_uefi.c | 40 ++++++++++++++-------------
> > 1 file changed, 21 insertions(+), 19 deletions(-)
> >
> > diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
> > index 81b19c52832b..b6c60fb3fb6c 100644
> > --- a/security/integrity/platform_certs/load_uefi.c
> > +++ b/security/integrity/platform_certs/load_uefi.c
> > @@ -1,4 +1,5 @@
> > // SPDX-License-Identifier: GPL-2.0
> > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> >
> > #include <linux/kernel.h>
> > #include <linux/sched.h>
> > @@ -39,7 +40,7 @@ static __init bool uefi_check_ignore_db(void)
> > * Get a certificate list blob from the named EFI variable.
> > */
> > static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
> > - unsigned long *size)
> > + unsigned long *size, const char *source)
> > {
> > efi_status_t status;
> > unsigned long lsize = 4;
> > @@ -48,23 +49,30 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
> >
> > status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
> > if (status != EFI_BUFFER_TOO_SMALL) {
> > - pr_err("Couldn't get size: 0x%lx\n", status);
> > - return NULL;
> > + if (status == EFI_NOT_FOUND) {
> > + pr_debug("%s list was not found\n", source);
> > + return NULL;
> > + }
> > + goto err;
> > }
> >
> > db = kmalloc(lsize, GFP_KERNEL);
> > - if (!db)
> > - return NULL;
> > + if (!db) {
> > + status = EFI_OUT_OF_RESOURCES;
> > + goto err;
> > + }
> >
> > status = efi.get_variable(name, guid, NULL, &lsize, db);
> > if (status != EFI_SUCCESS) {
> > kfree(db);
> > - pr_err("Error reading db var: 0x%lx\n", status);
> > - return NULL;
> > + goto err;
> > }
> >
> > *size = lsize;
> > return db;
> > +err:
> > + pr_err("Couldn't get %s list: %s\n", source, efi_status_to_str(status));
> > + return NULL;
> > }
> >
> > /*
> > @@ -153,10 +161,8 @@ static int __init load_uefi_certs(void)
> > * an error if we can't get them.
> > */
> > if (!uefi_check_ignore_db()) {
> > - db = get_cert_list(L"db", &secure_var, &dbsize);
> > - if (!db) {
> > - pr_err("MODSIGN: Couldn't get UEFI db list\n");
> > - } else {
> > + db = get_cert_list(L"db", &secure_var, &dbsize, "UEFI:db");
> > + if (db) {
> > rc = parse_efi_signature_list("UEFI:db",
> > db, dbsize, get_handler_for_db);
> > if (rc)
> > @@ -166,10 +172,8 @@ static int __init load_uefi_certs(void)
> > }
> > }
> >
> > - mok = get_cert_list(L"MokListRT", &mok_var, &moksize);
> > - if (!mok) {
> > - pr_info("Couldn't get UEFI MokListRT\n");
> > - } else {
> > + mok = get_cert_list(L"MokListRT", &mok_var, &moksize, "UEFI:MokListRT");
> > + if (mok) {
> > rc = parse_efi_signature_list("UEFI:MokListRT",
> > mok, moksize, get_handler_for_db);
> > if (rc)
> > @@ -177,10 +181,8 @@ static int __init load_uefi_certs(void)
> > kfree(mok);
> > }
> >
> > - dbx = get_cert_list(L"dbx", &secure_var, &dbxsize);
> > - if (!dbx) {
> > - pr_info("Couldn't get UEFI dbx list\n");
> > - } else {
> > + dbx = get_cert_list(L"dbx", &secure_var, &dbxsize, "UEFI:dbx");
> > + if (dbx) {
> > rc = parse_efi_signature_list("UEFI:dbx",
> > dbx, dbxsize,
> > get_handler_for_dbx);
> > --
> > 2.16.4
> >
next prev parent reply other threads:[~2019-12-13 9:38 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-13 9:06 [PATCH 0/2 v2] efi: cosmetic patches for the error messages when Lee, Chun-Yi
2019-12-13 9:06 ` [PATCH 1/2 v2] efi: add a function to convert the status code to a string Lee, Chun-Yi
2019-12-13 10:03 ` Ard Biesheuvel
2019-12-13 10:33 ` Joey Lee
2019-12-13 9:06 ` [PATCH 2/2] efi: show error messages only when loading certificates is failed Lee, Chun-Yi
2019-12-13 9:10 ` Ard Biesheuvel
2019-12-13 9:20 ` Joey Lee [this message]
2019-12-13 10:04 ` Ard Biesheuvel
2019-12-13 10:35 ` Joey Lee
-- strict thread matches above, loose matches on Subject: below --
2019-12-12 9:38 [PATCH 0/2] efi: cosmetic patches for the error messages when loading certificates Lee, Chun-Yi
2019-12-12 9:38 ` [PATCH 2/2] efi: show error messages only when loading certificates is failed Lee, Chun-Yi
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=20191213092049.GW22409@linux-l9pv.suse \
--to=jlee@suse.com \
--cc=ard.biesheuvel@linaro.org \
--cc=dhowells@redhat.com \
--cc=jmorris@namei.org \
--cc=joeyli.kernel@gmail.com \
--cc=jwboyer@fedoraproject.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=nayna@linux.ibm.com \
--cc=serge@hallyn.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).