From 8c81c24758ffbf17cf06c6835d361ffa57be2f0e Mon Sep 17 00:00:00 2001
From: Tadeusz Struk <tadeusz.struk@intel.com>
Date: Wed, 9 May 2018 11:55:35 -0700
Subject: [PATCH] tpm: fix use after free in tpm2_load_context()
References: bsc#1082555
Patch-mainline: v4.18-rc1
Git-commit: 8c81c24758ffbf17cf06c6835d361ffa57be2f0e
If load context command returns with TPM2_RC_HANDLE or TPM2_RC_REFERENCE_H0
then we have use after free in line 114 and double free in 117.
Fixes: 4d57856a21ed2 ("tpm2: add session handle context saving and restoring to the space code")
Cc: stable@vger.kernel.org
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off--by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
drivers/char/tpm/tpm2-space.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 4e4014eabdb9..6122d3276f72 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -102,8 +102,9 @@ static int tpm2_load_context(struct tpm_chip *chip, u8 *buf,
* TPM_RC_REFERENCE_H0 means the session has been
* flushed outside the space
*/
- rc = -ENOENT;
+ *handle = 0;
tpm_buf_destroy(&tbuf);
+ return -ENOENT;
} else if (rc > 0) {
dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n",
__func__, rc);
--
2.13.7