efivarfs: Ensure VariableName is NUL-terminated

Some buggy firmware implementations update VariableNameSize on success
such that it does not include the final NUL character which results in
garbage in the efivarfs name entries.  Use kzalloc on the efivar_entry
(as is done in efivars.c) to ensure that the name is always
NUL-terminated.

The buggy firmware is:
BIOS Information
        Vendor: Intel Corp.
        Version: S1200RP.86B.02.02.0005.102320140911
        Release Date: 10/23/2014
        BIOS Revision: 4.6
System Information
        Manufacturer: Intel Corporation
        Product Name: S1200RP_SE

Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Acked-by: Matthew Garrett <mjg59@coreos.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index ddbce42548c9fb6c6e496b609c1fb05beb98c944..acf9a67f6770940170889b9bb058e88272396d9f 100644 (file)
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -121,7 +121,7 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
        int len, i;
        int err = -ENOMEM;
 
-       entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+       entry = kzalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry)
                return err;