[GIT PULL 0/2] EFI urgent fixes

[GIT PULL 0/2] EFI urgent fixes

[Matt Fleming]

Folks, here are some bug fixes that missed the previous pull request
but that are related to those patches.

The following changes since commit 4682c211a80ee93214b72d95f861b0f6e90e5445:

  Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent (2016-02-16 13:14:57 +0100)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git tags/efi-urgent

for you to fetch changes up to a68075908a37850918ad96b056acc9ac4ce1bd90:

  lib/ucs2_string: Correct ucs2 -> utf8 conversion (2016-02-16 12:49:05 +0000)

----------------------------------------------------------------
 * Fix bugs in our code that converts ucs2 strings to utf8 where we
   unintentionally drop bits from the original string - Jason Andryuk

 * Add the efi-pstore variables to the variable whitelist so that
   users can continue to delete them via efivarfs without needing to
   manipulate the immutable flag - Matt Fleming

----------------------------------------------------------------
Jason Andryuk (1):
      lib/ucs2_string: Correct ucs2 -> utf8 conversion

Matt Fleming (1):
      efi: Add pstore variables to the deletion whitelist

 drivers/firmware/efi/vars.c |  1 +
 lib/ucs2_string.c           | 14 +++++++-------
 2 files changed, 8 insertions(+), 7 deletions(-)

[PATCH 1/2] efi: Add pstore variables to the deletion whitelist

[Matt Fleming]

Laszlo explains why this is a good idea,

 'This is because the pstore filesystem can be backed by UEFI variables,
  and (for example) a crash might dump the last kilobytes of the dmesg
  into a number of pstore entries, each entry backed by a separate UEFI
  variable in the above GUID namespace, and with a variable name
  according to the above pattern.

  Please see "drivers/firmware/efi/efi-pstore.c".

  While this patch series will not prevent the user from deleting those
  UEFI variables via the pstore filesystem (i.e., deleting a pstore fs
  entry will continue to delete the backing UEFI variable), I think it
  would be nice to preserve the possibility for the sysadmin to delete
  Linux-created UEFI variables that carry portions of the crash log,
  *without* having to mount the pstore filesystem.'

There's also no chance of causing machines to become bricked by
deleting these variables, which is the whole purpose of excluding
things from the whitelist.

Use the LINUX_EFI_CRASH_GUID guid and a wildcard '*' for the match so
that we don't have to update the string in the future if new variable
name formats are created for crash dump variables.

Reported-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Peter Jones <pjones@redhat.com>
Tested-by: Peter Jones <pjones@redhat.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: "Lee, Chun-Yi" <jlee@suse.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
 drivers/firmware/efi/vars.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 50f10bad2604..7f2ea21c730d 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -198,6 +198,7 @@ static const struct variable_validate variable_validate[] = {
 	{ EFI_GLOBAL_VARIABLE_GUID, "OsIndications", NULL },
 	{ EFI_GLOBAL_VARIABLE_GUID, "PlatformLang", validate_ascii_string },
 	{ EFI_GLOBAL_VARIABLE_GUID, "Timeout", validate_uint16 },
+	{ LINUX_EFI_CRASH_GUID, "*", NULL },
 	{ NULL_GUID, "", NULL },
 };
 
-- 
2.6.2

[PATCH 2/2] lib/ucs2_string: Correct ucs2 -> utf8 conversion

[Matt Fleming]

From: Jason Andryuk <jandryuk@gmail.com>

The comparisons should be >= since 0x800 and 0x80 require an additional bit
to store.

For the 3 byte case, the existing shift would drop off 2 more bits than
intended.

For the 2 byte case, there should be 5 bits bits in byte 1, and 6 bits in
byte 2.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Matthew Garrett <mjg59@coreos.com>
Cc: "Lee, Chun-Yi" <jlee@suse.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
 lib/ucs2_string.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib/ucs2_string.c b/lib/ucs2_string.c
index 17dd74e21ef9..f0b323abb4c6 100644
--- a/lib/ucs2_string.c
+++ b/lib/ucs2_string.c
@@ -59,9 +59,9 @@ ucs2_utf8size(const ucs2_char_t *src)
 	for (i = 0; i < ucs2_strlen(src); i++) {
 		u16 c = src[i];
 
-		if (c > 0x800)
+		if (c >= 0x800)
 			j += 3;
-		else if (c > 0x80)
+		else if (c >= 0x80)
 			j += 2;
 		else
 			j += 1;
@@ -88,19 +88,19 @@ ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength)
 	for (i = 0; maxlength && i < limit; i++) {
 		u16 c = src[i];
 
-		if (c > 0x800) {
+		if (c >= 0x800) {
 			if (maxlength < 3)
 				break;
 			maxlength -= 3;
 			dest[j++] = 0xe0 | (c & 0xf000) >> 12;
-			dest[j++] = 0x80 | (c & 0x0fc0) >> 8;
+			dest[j++] = 0x80 | (c & 0x0fc0) >> 6;
 			dest[j++] = 0x80 | (c & 0x003f);
-		} else if (c > 0x80) {
+		} else if (c >= 0x80) {
 			if (maxlength < 2)
 				break;
 			maxlength -= 2;
-			dest[j++] = 0xc0 | (c & 0xfe0) >> 5;
-			dest[j++] = 0x80 | (c & 0x01f);
+			dest[j++] = 0xc0 | (c & 0x7c0) >> 6;
+			dest[j++] = 0x80 | (c & 0x03f);
 		} else {
 			maxlength -= 1;
 			dest[j++] = c & 0x7f;
-- 
2.6.2

Re: [GIT PULL 0/2] EFI urgent fixes

[Ingo Molnar]

* Matt Fleming <matt@codeblueprint.co.uk> wrote:

> Folks, here are some bug fixes that missed the previous pull request
> but that are related to those patches.
> 
> The following changes since commit 4682c211a80ee93214b72d95f861b0f6e90e5445:
> 
>   Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent (2016-02-16 13:14:57 +0100)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git tags/efi-urgent
> 
> for you to fetch changes up to a68075908a37850918ad96b056acc9ac4ce1bd90:
> 
>   lib/ucs2_string: Correct ucs2 -> utf8 conversion (2016-02-16 12:49:05 +0000)
> 
> ----------------------------------------------------------------
>  * Fix bugs in our code that converts ucs2 strings to utf8 where we
>    unintentionally drop bits from the original string - Jason Andryuk
> 
>  * Add the efi-pstore variables to the variable whitelist so that
>    users can continue to delete them via efivarfs without needing to
>    manipulate the immutable flag - Matt Fleming
> 
> ----------------------------------------------------------------
> Jason Andryuk (1):
>       lib/ucs2_string: Correct ucs2 -> utf8 conversion
> 
> Matt Fleming (1):
>       efi: Add pstore variables to the deletion whitelist
> 
>  drivers/firmware/efi/vars.c |  1 +
>  lib/ucs2_string.c           | 14 +++++++-------
>  2 files changed, 8 insertions(+), 7 deletions(-)

Pulled, thanks Matt!

	Ingo