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authorMilan Broz <gmazyland@gmail.com>2019-07-04 09:26:15 +0200
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2019-08-05 00:55:00 +0300
commit1e5ac6300a07ceecfc70a893ebef3352be21e6f8 (patch)
tree2c28562eb49605b7f9bb035235451289808ce1ef
parent4b6f23161b4e888e72671e377c32eabe9a8e62fc (diff)
tpm: Fix null pointer dereference on chip register error path
If clk_enable is not defined and chip initialization is canceled code hits null dereference. Easily reproducible with vTPM init fail: swtpm chardev --tpmstate dir=nonexistent_dir --tpm2 --vtpm-proxy BUG: kernel NULL pointer dereference, address: 00000000 ... Call Trace: tpm_chip_start+0x9d/0xa0 [tpm] tpm_chip_register+0x10/0x1a0 [tpm] vtpm_proxy_work+0x11/0x30 [tpm_vtpm_proxy] process_one_work+0x214/0x5a0 worker_thread+0x134/0x3e0 ? process_one_work+0x5a0/0x5a0 kthread+0xd4/0x100 ? process_one_work+0x5a0/0x5a0 ? kthread_park+0x90/0x90 ret_from_fork+0x19/0x24 Fixes: 719b7d81f204 ("tpm: introduce tpm_chip_start() and tpm_chip_stop()") Cc: stable@vger.kernel.org # v5.1+ Signed-off-by: Milan Broz <gmazyland@gmail.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
-rw-r--r--drivers/char/tpm/tpm-chip.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
index d47ad10a35fe..bf868260f435 100644
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -77,6 +77,18 @@ static int tpm_go_idle(struct tpm_chip *chip)
return chip->ops->go_idle(chip);
}
+static void tpm_clk_enable(struct tpm_chip *chip)
+{
+ if (chip->ops->clk_enable)
+ chip->ops->clk_enable(chip, true);
+}
+
+static void tpm_clk_disable(struct tpm_chip *chip)
+{
+ if (chip->ops->clk_enable)
+ chip->ops->clk_enable(chip, false);
+}
+
/**
* tpm_chip_start() - power on the TPM
* @chip: a TPM chip to use
@@ -89,13 +101,12 @@ int tpm_chip_start(struct tpm_chip *chip)
{
int ret;
- if (chip->ops->clk_enable)
- chip->ops->clk_enable(chip, true);
+ tpm_clk_enable(chip);
if (chip->locality == -1) {
ret = tpm_request_locality(chip);
if (ret) {
- chip->ops->clk_enable(chip, false);
+ tpm_clk_disable(chip);
return ret;
}
}
@@ -103,8 +114,7 @@ int tpm_chip_start(struct tpm_chip *chip)
ret = tpm_cmd_ready(chip);
if (ret) {
tpm_relinquish_locality(chip);
- if (chip->ops->clk_enable)
- chip->ops->clk_enable(chip, false);
+ tpm_clk_disable(chip);
return ret;
}
@@ -124,8 +134,7 @@ void tpm_chip_stop(struct tpm_chip *chip)
{
tpm_go_idle(chip);
tpm_relinquish_locality(chip);
- if (chip->ops->clk_enable)
- chip->ops->clk_enable(chip, false);
+ tpm_clk_disable(chip);
}
EXPORT_SYMBOL_GPL(tpm_chip_stop);