A a potential race condition reported by one of my customers that leads to a NULL pointer dereference, where the call to efi.get_variable should be guarded with efi_rt_services_supported() to ensure that function exists.

Fixes: 4fe238513407 ("ALSA: hda/tas2781: Move and unified the calibrated-data getting function for SPI and I2C into the tas2781_hda lib") Signed-off-by: Shenghao Ding shenghao-ding@ti.com --- sound/hda/codecs/side-codecs/tas2781_hda.c | 5 +++++ sound/hda/codecs/side-codecs/tas2781_hda_i2c.c | 5 +++++ 2 files changed, 10 insertions(+)

diff --git a/sound/hda/codecs/side-codecs/tas2781_hda.c b/sound/hda/codecs/side-codecs/tas2781_hda.c index 536940c78f00..96e6d82dc69e 100644 --- a/sound/hda/codecs/side-codecs/tas2781_hda.c +++ b/sound/hda/codecs/side-codecs/tas2781_hda.c @@ -193,6 +193,11 @@ int tas2781_save_calibration(struct tas2781_hda *hda) efi_status_t status; int i;

+ if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) { + dev_err(p->dev, "%s: NO EFI FOUND!\n", __func__); + return -EINVAL; + } + if (hda->catlog_id < LENOVO) efi_guid = tasdev_fct_efi_guid[hda->catlog_id];

diff --git a/sound/hda/codecs/side-codecs/tas2781_hda_i2c.c b/sound/hda/codecs/side-codecs/tas2781_hda_i2c.c index 008dbe1490a7..4dea442d8c30 100644 --- a/sound/hda/codecs/side-codecs/tas2781_hda_i2c.c +++ b/sound/hda/codecs/side-codecs/tas2781_hda_i2c.c @@ -317,6 +317,11 @@ static int tas2563_save_calibration(struct tas2781_hda *h) unsigned int attr; int ret, i, j, k;

+ if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) { + dev_err(p->dev, "%s: NO EFI FOUND!\n", __func__); + return -EINVAL; + } + cd->cali_dat_sz_per_dev = TAS2563_CAL_DATA_SIZE * TASDEV_CALIB_N;

/* extra byte for each device is the device number */