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| author | Jarkko Sakkinen <jarkko@kernel.org> | 2023-04-26 20:29:28 +0300 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko@kernel.org> | 2023-05-16 02:43:12 +0300 |
| commit | 99d46450625590d410f86fe4660a5eff7d3b8343 (patch) | |
| tree | 446c3d6a59c7a4a8762954ee3e527ff0b257d686 /drivers/char/tpm/tpm-chip.c | |
| parent | 1398aa803f198b7a386fdd8404666043e95f4c16 (diff) | |
| download | linux-99d46450625590d410f86fe4660a5eff7d3b8343.tar.xz | |
tpm: Prevent hwrng from activating during resume
Set TPM_CHIP_FLAG_SUSPENDED in tpm_pm_suspend() and reset in
tpm_pm_resume(). While the flag is set, tpm_hwrng() gives back zero
bytes. This prevents hwrng from racing during resume.
Cc: stable@vger.kernel.org
Fixes: 6e592a065d51 ("tpm: Move Linux RNG connection to hwrng")
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Diffstat (limited to 'drivers/char/tpm/tpm-chip.c')
| -rw-r--r-- | drivers/char/tpm/tpm-chip.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index c10a4aa97373..cd48033b804a 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -571,6 +571,10 @@ static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait) { struct tpm_chip *chip = container_of(rng, struct tpm_chip, hwrng); + /* Give back zero bytes, as TPM chip has not yet fully resumed: */ + if (chip->flags & TPM_CHIP_FLAG_SUSPENDED) + return 0; + return tpm_get_random(chip, data, max); } |