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From:   Hanjun Guo <guohanjun@huawei.com>
To:     Jarkko Sakkinen <jarkko@kernel.org>,
        Peter Huewe <peterhuewe@gmx.de>
CC:     <linux-integrity@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        "Hanjun Guo" <guohanjun@huawei.com>
Subject: [PATCH v2 1/3] tpm: acpi: Call acpi_put_table() to fix memory leak
Date:   Thu, 17 Nov 2022 19:23:40 +0800
Message-ID: <1668684222-38457-2-git-send-email-guohanjun@huawei.com>
In-Reply-To: <1668684222-38457-1-git-send-email-guohanjun@huawei.com>
References: <1668684222-38457-1-git-send-email-guohanjun@huawei.com>
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The start and length of the event log area are obtained from
TPM2 or TCPA table, so we call acpi_get_table() to get the
ACPI information, but the acpi_get_table() should be coupled with
acpi_put_table() to release the ACPI memory, add the acpi_put_table()
properly to fix the memory leak.

While we are at it, remove the redundant empty line at the
end of the tpm_read_log_acpi().

Fixes: 0bfb23746052 ("tpm: Move eventlog files to a subdirectory")
Fixes: 85467f63a05c ("tpm: Add support for event log pointer found in TPM2 ACPI table")
Cc: stable@vger.kernel.org
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
---
 drivers/char/tpm/eventlog/acpi.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c
index 1b18ce5..0913d3eb 100644
--- a/drivers/char/tpm/eventlog/acpi.c
+++ b/drivers/char/tpm/eventlog/acpi.c
@@ -90,16 +90,21 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
 			return -ENODEV;
 
 		if (tbl->header.length <
-				sizeof(*tbl) + sizeof(struct acpi_tpm2_phy))
+				sizeof(*tbl) + sizeof(struct acpi_tpm2_phy)) {
+			acpi_put_table((struct acpi_table_header *)tbl);
 			return -ENODEV;
+		}
 
 		tpm2_phy = (void *)tbl + sizeof(*tbl);
 		len = tpm2_phy->log_area_minimum_length;
 
 		start = tpm2_phy->log_area_start_address;
-		if (!start || !len)
+		if (!start || !len) {
+			acpi_put_table((struct acpi_table_header *)tbl);
 			return -ENODEV;
+		}
 
+		acpi_put_table((struct acpi_table_header *)tbl);
 		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2;
 	} else {
 		/* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
@@ -120,8 +125,10 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
 			break;
 		}
 
+		acpi_put_table((struct acpi_table_header *)buff);
 		format = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2;
 	}
+
 	if (!len) {
 		dev_warn(&chip->dev, "%s: TCPA log area empty\n", __func__);
 		return -EIO;
@@ -156,5 +163,4 @@ int tpm_read_log_acpi(struct tpm_chip *chip)
 	kfree(log->bios_event_log);
 	log->bios_event_log = NULL;
 	return ret;
-
 }
-- 
1.7.12.4