remarkable-linux/drivers/char/tpm/tpm_of.c
Christophe JAILLET eb8ed1eb9a TPM: Avoid reference to potentially freed memory
Reference to the 'np' node is dropped before dereferencing the 'sizep' and
'basep' pointers, which could by then point to junk if the node has been
freed.

Refactor code to call 'of_node_put' later.

Fixes: c5df39262d ("drivers/char/tpm: Add securityfs support for event log")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Peter Huewe <PeterHuewe@gmx.de>
2015-11-09 17:52:55 +02:00

75 lines
1.7 KiB
C

/*
* Copyright 2012 IBM Corporation
*
* Author: Ashley Lai <ashleydlai@gmail.com>
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* Read the event log created by the firmware on PPC64
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/slab.h>
#include <linux/of.h>
#include "tpm.h"
#include "tpm_eventlog.h"
int read_log(struct tpm_bios_log *log)
{
struct device_node *np;
const u32 *sizep;
const u64 *basep;
if (log->bios_event_log != NULL) {
pr_err("%s: ERROR - Eventlog already initialized\n", __func__);
return -EFAULT;
}
np = of_find_node_by_name(NULL, "vtpm");
if (!np) {
pr_err("%s: ERROR - IBMVTPM not supported\n", __func__);
return -ENODEV;
}
sizep = of_get_property(np, "linux,sml-size", NULL);
if (sizep == NULL) {
pr_err("%s: ERROR - SML size not found\n", __func__);
goto cleanup_eio;
}
if (*sizep == 0) {
pr_err("%s: ERROR - event log area empty\n", __func__);
goto cleanup_eio;
}
basep = of_get_property(np, "linux,sml-base", NULL);
if (basep == NULL) {
pr_err("%s: ERROR - SML not found\n", __func__);
goto cleanup_eio;
}
log->bios_event_log = kmalloc(*sizep, GFP_KERNEL);
if (!log->bios_event_log) {
pr_err("%s: ERROR - Not enough memory for BIOS measurements\n",
__func__);
of_node_put(np);
return -ENOMEM;
}
log->bios_event_log_end = log->bios_event_log + *sizep;
memcpy(log->bios_event_log, __va(*basep), *sizep);
of_node_put(np);
return 0;
cleanup_eio:
of_node_put(np);
return -EIO;
}