diff mbox series

[2/2] efi: show error messages only when loading certificates is failed

Message ID 20191213090646.12329-3-jlee@suse.com (mailing list archive)
State New, archived
Headers show
Series efi: cosmetic patches for the error messages when | expand

Commit Message

Lee, Chun-Yi Dec. 13, 2019, 9:06 a.m. UTC
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.

Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
---
 security/integrity/platform_certs/load_uefi.c | 40 ++++++++++++++-------------
 1 file changed, 21 insertions(+), 19 deletions(-)

Comments

Ard Biesheuvel Dec. 13, 2019, 9:10 a.m. UTC | #1
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?

> 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
>
joeyli Dec. 13, 2019, 9:20 a.m. UTC | #2
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
> >
Ard Biesheuvel Dec. 13, 2019, 10:04 a.m. UTC | #3
On Fri, 13 Dec 2019 at 10:21, Joey Lee <JLee@suse.com> wrote:
>
> 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.
>

OK, that works for me.

I take it this will go via the linux-security tree along with 1/2?

Acked-by: Ard Biesheuvel <ardb@kernel.org>



> > > 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
> > >
joeyli Dec. 13, 2019, 10:35 a.m. UTC | #4
Hi Ard,

On Fri, Dec 13, 2019 at 10:04:14AM +0000, Ard Biesheuvel wrote:
> On Fri, 13 Dec 2019 at 10:21, Joey Lee <JLee@suse.com> wrote:
> >
> > 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.
> >
> 
> OK, that works for me.
> 
> I take it this will go via the linux-security tree along with 1/2?
>

Yes, this patch must go with 1/2 patch. 
 
> Acked-by: Ard Biesheuvel <ardb@kernel.org>
> 

Thanks for your review!

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
> > > >
diff mbox series

Patch

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);