| Message ID | 20180406160541.8188-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Apr 06, 2018 at 05:05:41PM +0100, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > Currently chip is being dereferenced by the call to dev_get_drvdata > before it is being null checked, hence we have a potential null > pointer dereference bug. Fix this by only dereferencing it after the > null check. > > Detected by CoverityScan, CID#1357806 ("Dereference before null check") > > Fixes: 9e0d39d8a6a0 ("tpm: Remove useless priv field in struct tpm_vendor_specific") > Signed-off-by: Colin Ian King <colin.king@canonical.com> > drivers/char/tpm/st33zp24/st33zp24.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c > index f95b9c75175b..476865d66a0e 100644 > +++ b/drivers/char/tpm/st33zp24/st33zp24.c > @@ -367,7 +367,7 @@ static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id) > static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf, > size_t len) > { > - struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); > + struct st33zp24_dev *tpm_dev; > u32 status, i, size, ordinal; > int burstcnt = 0; > int ret; Chip can't be NULL here, so I would prefer to see the NULL test deleted. Thanks, Jason
diff --git a/drivers/char/tpm/st33zp24/st33zp24.c b/drivers/char/tpm/st33zp24/st33zp24.c index f95b9c75175b..476865d66a0e 100644 --- a/drivers/char/tpm/st33zp24/st33zp24.c +++ b/drivers/char/tpm/st33zp24/st33zp24.c @@ -367,7 +367,7 @@ static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id) static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf, size_t len) { - struct st33zp24_dev *tpm_dev = dev_get_drvdata(&chip->dev); + struct st33zp24_dev *tpm_dev; u32 status, i, size, ordinal; int burstcnt = 0; int ret; @@ -378,6 +378,7 @@ static int st33zp24_send(struct tpm_chip *chip, unsigned char *buf, if (len < TPM_HEADER_SIZE) return -EBUSY; + tpm_dev = dev_get_drvdata(&chip->dev); ret = request_locality(chip); if (ret < 0) return ret;