Commit 7dc357d3 authored by Hao Ge's avatar Hao Ge Committed by Jarkko Sakkinen
Browse files

tpm: Use auth only after NULL check in tpm_buf_check_hmac_response() 



Dereference auth after NULL check in tpm_buf_check_hmac_response().
Otherwise, unless tpm2_sessions_init() was called, a call can cause NULL
dereference, when TCG_TPM2_HMAC is enabled.

[jarkko: adjusted the commit message.]
Cc: stable@vger.kernel.org # v6.10+
Fixes: 7ca110f2 ("tpm: Address !chip->auth in tpm_buf_append_hmac_session*()")
Signed-off-by: default avatarHao Ge <gehao@kylinos.cn>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
parent d6797831

drivers/char/tpm/tpm2-sessions.c

+3 −2
Original line number Diff line number Diff line
@@ -746,15 +746,16 @@ int tpm_buf_check_hmac_response(struct tpm_chip *chip, struct tpm_buf *buf, 
	struct tpm2_auth *auth = chip->auth;

	off_t offset_s, offset_p;

	u8 rphash[SHA256_DIGEST_SIZE];

	u32 attrs;

	u32 attrs, cc;

	struct sha256_state sctx;

	u16 tag = be16_to_cpu(head->tag);

	u32 cc = be32_to_cpu(auth->ordinal);

	int parm_len, len, i, handles;



	if (!auth)

		return rc;



	cc = be32_to_cpu(auth->ordinal);



	if (auth->session >= TPM_HEADER_SIZE) {

		WARN(1, "tpm session not filled correctly\n");

		goto out;