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@vger.kernel.org # v6.4+ Fixes: 99d464506255 ("tpm: Prevent hwrng from activating during resume") Reported-by: Mike Seo mikeseohyungjin@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219383 Signed-off-by: Jarkko Sakkinen jarkko@kernel.org --- 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;