提交 123abd76 编写于 作者: M Matt Fleming

efivars: efivarfs_valid_name() should handle pstore syntax

Stricter validation was introduced with commit da27a243
("efivarfs: guid part of filenames are case-insensitive") and commit
47f531e8 ("efivarfs: Validate filenames much more aggressively"),
which is necessary for the guid portion of efivarfs filenames, but we
don't need to be so strict with the first part, the variable name. The
UEFI specification doesn't impose any constraints on variable names
other than they be a NULL-terminated string.

The above commits caused a regression that resulted in users seeing
the following message,

  $ sudo mount -v /sys/firmware/efi/efivars mount: Cannot allocate memory

whenever pstore EFI variables were present in the variable store,
since their variable names failed to pass the following check,

    /* GUID should be right after the first '-' */
    if (s - 1 != strchr(str, '-'))

as a typical pstore filename is of the form, dump-type0-10-1-<guid>.
The fix is trivial since the guid portion of the filename is GUID_LEN
bytes, we can use (len - GUID_LEN) to ensure the '-' character is
where we expect it to be.

(The bogus ENOMEM error value will be fixed in a separate patch.)
Reported-by: NJoseph Yasi <joe.yasi@gmail.com>
Tested-by: NJoseph Yasi <joe.yasi@gmail.com>
Reported-by: NLingzhu Xiang <lxiang@redhat.com>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: <stable@vger.kernel.org> # v3.8
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
上级 68d92986
......@@ -974,8 +974,8 @@ static bool efivarfs_valid_name(const char *str, int len)
if (len < GUID_LEN + 2)
return false;
/* GUID should be right after the first '-' */
if (s - 1 != strchr(str, '-'))
/* GUID must be preceded by a '-' */
if (*(s - 1) != '-')
return false;
/*
......
......@@ -125,6 +125,63 @@ test_open_unlink()
./open-unlink $file
}
# test that we can create a range of filenames
test_valid_filenames()
{
local attrs='\x07\x00\x00\x00'
local ret=0
local file_list="abc dump-type0-11-1-1362436005 1234 -"
for f in $file_list; do
local file=$efivarfs_mount/$f-$test_guid
printf "$attrs\x00" > $file
if [ ! -e $file ]; then
echo "$file could not be created" >&2
ret=1
else
rm $file
fi
done
exit $ret
}
test_invalid_filenames()
{
local attrs='\x07\x00\x00\x00'
local ret=0
local file_list="
-1234-1234-1234-123456789abc
foo
foo-bar
-foo-
foo-barbazba-foob-foob-foob-foobarbazfoo
foo-------------------------------------
-12345678-1234-1234-1234-123456789abc
a-12345678=1234-1234-1234-123456789abc
a-12345678-1234=1234-1234-123456789abc
a-12345678-1234-1234=1234-123456789abc
a-12345678-1234-1234-1234=123456789abc
1112345678-1234-1234-1234-123456789abc"
for f in $file_list; do
local file=$efivarfs_mount/$f
printf "$attrs\x00" 2>/dev/null > $file
if [ -e $file ]; then
echo "Creating $file should have failed" >&2
rm $file
ret=1
fi
done
exit $ret
}
check_prereqs
rc=0
......@@ -135,5 +192,7 @@ run_test test_create_read
run_test test_delete
run_test test_zero_size_delete
run_test test_open_unlink
run_test test_valid_filenames
run_test test_invalid_filenames
exit $rc
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