Messages in this thread | | | Subject | Re: [PATCH v6] tpm: Check size of response before accessing data | From | Stefan Berger <> | Date | Tue, 17 Jan 2017 17:27:47 -0500 |
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On 01/17/2017 09:49 AM, Jarkko Sakkinen wrote: > On Mon, Jan 16, 2017 at 04:41:11PM -0500, Stefan Berger wrote: > >> + * @min_rx_length: minimum expected length of response > Please, rename as min_rsp_body_len and change the description > accordingly. > >> * @flags: tpm transmit flags - bitmap >> * @desc: command description used in the error message >> * >> @@ -434,25 +435,34 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz, >> * A positive number for a TPM error. >> */ >> ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd, >> - int len, unsigned int flags, const char *desc) >> + size_t cmd_length, size_t min_rx_length, >> + unsigned int flags, const char *desc) >> { >> const struct tpm_output_header *header; >> int err; >> + ssize_t len; >> >> - len = tpm_transmit(chip, (const u8 *)cmd, len, flags); >> + len = tpm_transmit(chip, (const u8 *)cmd, cmd_length, flags); >> if (len < 0) >> return len; >> else if (len < TPM_HEADER_SIZE) >> return -EFAULT; >> >> header = cmd; >> + if (len < be32_to_cpu(header->length)) >> + return -EFAULT; >> >> err = be32_to_cpu(header->return_code); >> if (err != 0 && desc) >> dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err, >> desc); >> + if (err) >> + return err; >> >> - return err; >> + if (be32_to_cpu(header->length) < min_rx_length) >> + return -EFAULT; >> + >> + return 0; >> } >> >> #define TPM_DIGEST_SIZE 20 >> @@ -468,7 +478,7 @@ static const struct tpm_input_header tpm_getcap_header = { >> }; >> >> ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, >> - const char *desc) >> + const char *desc, size_t min_cap_length) > tpm_getcap update should be its own commit.
tpm_getcap needs to pass something as min_rsp_body_length to tpm_transmit_cmd. What would it pass?
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