Commit e66effaf authored by Nayna Jain's avatar Nayna Jain Committed by Michael Ellerman
Browse files

security/integrity: fix pointer to ESL data and its size on pseries 



On PowerVM guest, variable data is prefixed with 8 bytes of timestamp.
Extract ESL by stripping off the timestamp before passing to ESL parser.

Fixes: 4b3e71e9 ("integrity/powerpc: Support loading keys from PLPKS")
Cc: stable@vger.kenrnel.org # v6.3
Signed-off-by: default avatarNayna Jain <nayna@linux.ibm.com>
Tested-by: default avatarNageswara R Sastry <rnsastry@linux.ibm.com>
Acked-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230608120444.382527-1-nayna@linux.ibm.com
parent c8eebc4a

security/integrity/platform_certs/load_powerpc.c

+26 −14
Original line number Diff line number Diff line
@@ -15,6 +15,9 @@ 
#include "keyring_handler.h"

#include "../integrity.h"



#define extract_esl(db, data, size, offset)	\

	do { db = data + offset; size = size - offset; } while (0)



/*

 * Get a certificate list blob from the named secure variable.

 *
@@ -55,8 +58,9 @@ static __init void *get_cert_list(u8 *key, unsigned long keylen, u64 *size) 
 */

static int __init load_powerpc_certs(void)

{

	void *db = NULL, *dbx = NULL;

	u64 dbsize = 0, dbxsize = 0;

	void *db = NULL, *dbx = NULL, *data = NULL;

	u64 dsize = 0;

	u64 offset = 0;

	int rc = 0;

	ssize_t len;

	char buf[32];
@@ -74,38 +78,46 @@ static int __init load_powerpc_certs(void) 
		return -ENODEV;

	}



	if (strcmp("ibm,plpks-sb-v1", buf) == 0)

		/* PLPKS authenticated variables ESL data is prefixed with 8 bytes of timestamp */

		offset = 8;



	/*

	 * Get db, and dbx. They might not exist, so it isn't an error if we

	 * can't get them.

	 */

	db = get_cert_list("db", 3, &dbsize);

	if (!db) {

	data = get_cert_list("db", 3, &dsize);

	if (!data) {

		pr_info("Couldn't get db list from firmware\n");

	} else if (IS_ERR(db)) {

		rc = PTR_ERR(db);

	} else if (IS_ERR(data)) {

		rc = PTR_ERR(data);

		pr_err("Error reading db from firmware: %d\n", rc);

		return rc;

	} else {

		rc = parse_efi_signature_list("powerpc:db", db, dbsize,

		extract_esl(db, data, dsize, offset);



		rc = parse_efi_signature_list("powerpc:db", db, dsize,

					      get_handler_for_db);

		if (rc)

			pr_err("Couldn't parse db signatures: %d\n", rc);

		kfree(db);

		kfree(data);

	}



	dbx = get_cert_list("dbx", 4,  &dbxsize);

	if (!dbx) {

	data = get_cert_list("dbx", 4,  &dsize);

	if (!data) {

		pr_info("Couldn't get dbx list from firmware\n");

	} else if (IS_ERR(dbx)) {

		rc = PTR_ERR(dbx);

	} else if (IS_ERR(data)) {

		rc = PTR_ERR(data);

		pr_err("Error reading dbx from firmware: %d\n", rc);

		return rc;

	} else {

		rc = parse_efi_signature_list("powerpc:dbx", dbx, dbxsize,

		extract_esl(dbx, data, dsize, offset);



		rc = parse_efi_signature_list("powerpc:dbx", dbx, dsize,

					      get_handler_for_dbx);

		if (rc)

			pr_err("Couldn't parse dbx signatures: %d\n", rc);

		kfree(dbx);

		kfree(data);

	}



	return rc;