linux-stable.git/drivers/firmware/efi, branch linux-3.14.y

efi: Fix out-of-bounds read in variable_matches()

2016-05-04T21:51:24+00:00

commit 630ba0cc7a6dbafbdee43795617c872b35cde1b4 upstream.

The variable_matches() function can currently read "var_name[len]", for
example when:

 - var_name[0] == 'a',
 - len == 1
 - match_name points to the NUL-terminated string "ab".

This function is supposed to accept "var_name" inputs that are not
NUL-terminated (hence the "len" parameter"). Document the function, and
access "var_name[*match]" only if "*match" is smaller than "len".

Reported-by: Chris Wilson 
Signed-off-by: Laszlo Ersek 
Cc: Peter Jones 
Cc: Matthew Garrett 
Cc: Jason Andryuk 
Cc: Jani Nikula 
Link: http://thread.gmane.org/gmane.comp.freedesktop.xorg.drivers.intel/86906
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Add pstore variables to the deletion whitelist

2016-03-16T15:42:21+00:00

commit e246eb568bc4cbbdd8a30a3c11151ff9b7ca7312 upstream.

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 
Acked-by: Peter Jones 
Tested-by: Peter Jones 
Cc: Matthew Garrett 
Cc: "Lee, Chun-Yi" 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Make efivarfs entries immutable by default

2016-03-16T15:42:21+00:00

commit ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879 upstream.

"rm -rf" is bricking some peoples' laptops because of variables being
used to store non-reinitializable firmware driver data that's required
to POST the hardware.

These are 100% bugs, and they need to be fixed, but in the mean time it
shouldn't be easy to *accidentally* brick machines.

We have to have delete working, and picking which variables do and don't
work for deletion is quite intractable, so instead make everything
immutable by default (except for a whitelist), and make tools that
aren't quite so broad-spectrum unset the immutable flag.

Signed-off-by: Peter Jones 
Tested-by: Lee, Chun-Yi 
Acked-by: Matthew Garrett 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Make our variable validation list include the guid

2016-03-16T15:42:21+00:00

commit 8282f5d9c17fe15a9e658c06e3f343efae1a2a2f upstream.

All the variables in this list so far are defined to be in the global
namespace in the UEFI spec, so this just further ensures we're
validating the variables we think we are.

Including the guid for entries will become more important in future
patches when we decide whether or not to allow deletion of variables
based on presence in this list.

Signed-off-by: Peter Jones 
Tested-by: Lee, Chun-Yi 
Acked-by: Matthew Garrett 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Do variable name validation tests in utf8

2016-03-16T15:42:20+00:00

commit 3dcb1f55dfc7631695e69df4a0d589ce5274bd07 upstream.

Actually translate from ucs2 to utf8 before doing the test, and then
test against our other utf8 data, instead of fudging it.

Signed-off-by: Peter Jones 
Acked-by: Matthew Garrett 
Tested-by: Lee, Chun-Yi 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version

2016-03-16T15:42:20+00:00

commit e0d64e6a880e64545ad7d55786aa84ab76bac475 upstream.

Translate EFI's UCS-2 variable names to UTF-8 instead of just assuming
all variable names fit in ASCII.

Signed-off-by: Peter Jones 
Acked-by: Matthew Garrett 
Tested-by: Lee, Chun-Yi 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Small leak on error in runtime map code

2015-03-18T12:31:33+00:00

commit 86d68a58d00db3770735b5919ef2c6b12d7f06f3 upstream.

The "> 0" here should ">= 0" so we free map_entries[0].

Fixes: 926172d46038 ('efi: Export EFI runtime memory mapping to sysfs')
Signed-off-by: Dan Carpenter 
Acked-by: Dave Young 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

firmware: Do not use WARN_ON(!spin_is_locked())

2014-09-17T16:19:08+00:00

commit aee530cfecf4f3ec83b78406bac618cec35853f8 upstream.

spin_is_locked() always returns false for uniprocessor configurations
in several architectures, so do not use WARN_ON with it.
Use lockdep_assert_held() instead to also reduce overhead in
non-debug kernels.

Signed-off-by: Guenter Roeck 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi-pstore: Fix an overflow on 32-bit builds

2014-07-01T03:12:02+00:00

commit 783ee43118dc773bc8b0342c5b230e017d5a04d0 upstream.

In generic_id the long int timestamp is multiplied by 100000 and needs
an explicit cast to u64.

Without that the id in the resulting pstore filename is wrong and
userspace may have problems parsing it, but more importantly files in
pstore can never be deleted and may fill the EFI flash (brick device?).
This happens because when generic pstore code wants to delete a file,
it passes the id to the EFI backend which reinterpretes it and a wrong
variable name is attempted to be deleted.  There's no error message but
after remounting pstore, deleted files would reappear.

Signed-off-by: Andrew Zaborowski 
Acked-by: David Rientjes 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman

efi: Pass correct file handle to efi_file_{read,close}

2014-05-06T14:59:29+00:00

commit 47514c996fac5e6f13ef3a4c5e23f1c5cffabb7b upstream.

We're currently passing the file handle for the root file system to
efi_file_read() and efi_file_close(), instead of the file handle for the
file we wish to read/close.

While this has worked up until now, it seems that it has only been by
pure luck. Olivier explains,

 "The issue is the UEFI Fat driver might return the same function for
  'fh->read()' and 'h->read()'. While in our case it does not work with
  a different implementation of EFI_SIMPLE_FILE_SYSTEM_PROTOCOL. In our
  case, we return a different pointer when reading a directory and
  reading a file."

Fixing this actually clears up the two functions because we can drop one
of the arguments, and instead only pass a file 'handle' argument.

Reported-by: Olivier Martin 
Reviewed-by: Olivier Martin 
Reviewed-by: Mark Rutland 
Cc: Leif Lindholm 
Signed-off-by: Matt Fleming 
Signed-off-by: Greg Kroah-Hartman