Setting TPM_CHIP_FLAG_SUSPENDED in the end of tpm_pm_suspend() can be racy
according to the bug report, as this leaves window for tpm_hwrng_read() to
be called while the operation is in progress. Move setting of the flag
into the beginning.
Cc: stable@xxxxxxxxxxxxxxx # v6.4+
Fixes: 99d464506255 ("tpm: Prevent hwrng from activating during resume")
Reported-by: Mike Seo <mikeseohyungjin@xxxxxxxxx>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219383
Signed-off-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
---
drivers/char/tpm/tpm-interface.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 8134f002b121..3f96bc8b95df 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -370,6 +370,8 @@ int tpm_pm_suspend(struct device *dev)
if (!chip)
return -ENODEV;
+ chip->flags |= TPM_CHIP_FLAG_SUSPENDED;
+
if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
goto suspended;
@@ -390,8 +392,6 @@ int tpm_pm_suspend(struct device *dev)
}
suspended:
- chip->flags |= TPM_CHIP_FLAG_SUSPENDED;
-
if (rc)
dev_err(dev, "Ignoring error %d while suspending\n", rc);
return 0;
--
2.47.0
