From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bedivere.hansenpartnership.com (bedivere.hansenpartnership.com [96.44.175.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6AD941A3A9C; Tue, 24 Sep 2024 13:33:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.44.175.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727184817; cv=none; b=ChFqNckVqQ9eiPzJGVXk9jC+DJ3Tqi051eS66Lz9ELzYnq2cwW0Bgw58thKdCpPri0w7o0w08twbJRQfk53LM2Wf+pGrQqnIBhC4QR8T4HI7GQ4VxcfAVBKwtNtim7kCVvb1Vcm9RcAhl5DnvvKBG4BAxER5av5N1OYzqjlOEkI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727184817; c=relaxed/simple; bh=mbGoAUpUUbUuilJ7AHRgBLUhYKSQwMRi4QXDEsoCvWE=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=DvtsIJ8pD4A4OoJA5p9lwgcU0ANxPDH1fbRPk8qK8TKlFZTJoBAVJ5Ln4ebf5MTp4Fl6veUCRiPlyFojGY4nd5CdfX/WM90OXYfhZcdLgBhj6Ip5tF5VOjJxsrsQKn6vL5Dba8ISHPxJ6HydQ5CPtTOCG61vPhwU2Xin6IYRYtc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=YXq4bgsf; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=YXq4bgsf; arc=none smtp.client-ip=96.44.175.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="YXq4bgsf"; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="YXq4bgsf" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1727184814; bh=mbGoAUpUUbUuilJ7AHRgBLUhYKSQwMRi4QXDEsoCvWE=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References:From; b=YXq4bgsfhiTv/+ZDRCzpsvzBc8wrG08EWnvUwJjnorIY5EJlvt+caHDGpAK4L2YB0 ZBYk4lIGHPSZIJDGLM/xrA6pqkDSFO/OxilWunN2XcWxlUlseFGCrbdhIGLlaZ127D SWUJ1Z4qgyKp69mun4HqVklP/TWFmg4Z1DNRgqLM= Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id 59D611287B39; Tue, 24 Sep 2024 09:33:34 -0400 (EDT) Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavis, port 10024) with ESMTP id 3yan6ws8wMA7; Tue, 24 Sep 2024 09:33:34 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1727184814; bh=mbGoAUpUUbUuilJ7AHRgBLUhYKSQwMRi4QXDEsoCvWE=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References:From; b=YXq4bgsfhiTv/+ZDRCzpsvzBc8wrG08EWnvUwJjnorIY5EJlvt+caHDGpAK4L2YB0 ZBYk4lIGHPSZIJDGLM/xrA6pqkDSFO/OxilWunN2XcWxlUlseFGCrbdhIGLlaZ127D SWUJ1Z4qgyKp69mun4HqVklP/TWFmg4Z1DNRgqLM= Received: from lingrow.int.hansenpartnership.com (unknown [IPv6:2601:5c4:4302:c21::a774]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id D45051285D46; Tue, 24 Sep 2024 09:33:32 -0400 (EDT) Message-ID: <12e17497239dd9b47059b03a0273e2d995371278.camel@HansenPartnership.com> Subject: Re: [PATCH v5 4/5] tpm: Allocate chip->auth in tpm2_start_auth_session() From: James Bottomley To: Jarkko Sakkinen , linux-integrity@vger.kernel.org Cc: roberto.sassu@huawei.com, mapengyu@gmail.com, stable@vger.kernel.org, Mimi Zohar , David Howells , Paul Moore , James Morris , "Serge E. Hallyn" , Peter Huewe , Jason Gunthorpe , keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 24 Sep 2024 09:33:30 -0400 In-Reply-To: <20240921120811.1264985-5-jarkko@kernel.org> References: <20240921120811.1264985-1-jarkko@kernel.org> <20240921120811.1264985-5-jarkko@kernel.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.42.4 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Sat, 2024-09-21 at 15:08 +0300, Jarkko Sakkinen wrote: > Move allocation of chip->auth to tpm2_start_auth_session() so that > the field can be used as flag to tell whether auth session is active > or not. > > Cc: stable@vger.kernel.org # v6.10+ > Fixes: 699e3efd6c64 ("tpm: Add HMAC session start and end functions") > Signed-off-by: Jarkko Sakkinen > --- > v5: > - No changes. > v4: > - Change to bug. > v3: > - No changes. > v2: > - A new patch. > --- >  drivers/char/tpm/tpm2-sessions.c | 43 +++++++++++++++++++----------- > -- >  1 file changed, 25 insertions(+), 18 deletions(-) > > diff --git a/drivers/char/tpm/tpm2-sessions.c > b/drivers/char/tpm/tpm2-sessions.c > index 1aef5b1f9c90..a8d3d5d52178 100644 > --- a/drivers/char/tpm/tpm2-sessions.c > +++ b/drivers/char/tpm/tpm2-sessions.c > @@ -484,7 +484,8 @@ static void tpm2_KDFe(u8 z[EC_PT_SZ], const char > *str, u8 *pt_u, u8 *pt_v, >         sha256_final(&sctx, out); >  } >   > -static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip > *chip) > +static void tpm_buf_append_salt(struct tpm_buf *buf, struct tpm_chip > *chip, > +                               struct tpm2_auth *auth) This addition of auth as an argument is a bit unnecessary. You can set chip->auth before calling this and it will all function. Since there's no error leg in tpm2_start_auth_session unless the session creation itself fails and the guarantee of the ops lock is single threading this chip->auth can be nulled again in that error leg. If you want to keep the flow proposed in the patch, the change from how it works now to how it works with this patch needs documenting in the change log >  { >         struct crypto_kpp *kpp; >         struct kpp_request *req; > @@ -543,7 +544,7 @@ static void tpm_buf_append_salt(struct tpm_buf > *buf, struct tpm_chip *chip) >         sg_set_buf(&s[0], chip->null_ec_key_x, EC_PT_SZ); >         sg_set_buf(&s[1], chip->null_ec_key_y, EC_PT_SZ); >         kpp_request_set_input(req, s, EC_PT_SZ*2); > -       sg_init_one(d, chip->auth->salt, EC_PT_SZ); > +       sg_init_one(d, auth->salt, EC_PT_SZ); >         kpp_request_set_output(req, d, EC_PT_SZ); >         crypto_kpp_compute_shared_secret(req); >         kpp_request_free(req); > @@ -554,8 +555,7 @@ static void tpm_buf_append_salt(struct tpm_buf > *buf, struct tpm_chip *chip) >          * This works because KDFe fully consumes the secret before > it >          * writes the salt >          */ > -       tpm2_KDFe(chip->auth->salt, "SECRET", x, chip->null_ec_key_x, > -                 chip->auth->salt); > +       tpm2_KDFe(auth->salt, "SECRET", x, chip->null_ec_key_x, auth- > >salt); >   >   out: >         crypto_free_kpp(kpp); > @@ -854,6 +854,8 @@ int tpm_buf_check_hmac_response(struct tpm_chip > *chip, struct tpm_buf *buf, >                         /* manually close the session if it wasn't > consumed */ >                         tpm2_flush_context(chip, auth->handle); >                 memzero_explicit(auth, sizeof(*auth)); > +               kfree(auth); > +               chip->auth = NULL; >         } else { >                 /* reset for next use  */ >                 auth->session = TPM_HEADER_SIZE; > @@ -882,6 +884,8 @@ void tpm2_end_auth_session(struct tpm_chip *chip) >   >         tpm2_flush_context(chip, auth->handle); >         memzero_explicit(auth, sizeof(*auth)); > +       kfree(auth); > +       chip->auth = NULL; >  } >  EXPORT_SYMBOL(tpm2_end_auth_session); >   > @@ -970,25 +974,29 @@ static int tpm2_load_null(struct tpm_chip > *chip, u32 *null_key) >   */ >  int tpm2_start_auth_session(struct tpm_chip *chip) >  { > +       struct tpm2_auth *auth; >         struct tpm_buf buf; > -       struct tpm2_auth *auth = chip->auth; > -       int rc; >         u32 null_key; > +       int rc; >   > -       if (!auth) { > -               dev_warn_once(&chip->dev, "auth session is not > active\n"); > +       if (chip->auth) { > +               dev_warn_once(&chip->dev, "auth session is > active\n"); >                 return 0; >         } >   > +       auth = kzalloc(sizeof(*auth), GFP_KERNEL); > +       if (!auth) > +               return -ENOMEM; > + >         rc = tpm2_load_null(chip, &null_key); >         if (rc) > -               goto out; > +               goto err; >   >         auth->session = TPM_HEADER_SIZE; >   >         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, > TPM2_CC_START_AUTH_SESS); >         if (rc) > -               goto out; > +               goto err; >   >         /* salt key handle */ >         tpm_buf_append_u32(&buf, null_key); > @@ -1000,7 +1008,7 @@ int tpm2_start_auth_session(struct tpm_chip > *chip) >         tpm_buf_append(&buf, auth->our_nonce, sizeof(auth- > >our_nonce)); >   >         /* append encrypted salt and squirrel away unencrypted in > auth */ > -       tpm_buf_append_salt(&buf, chip); > +       tpm_buf_append_salt(&buf, chip, auth); >         /* session type (HMAC, audit or policy) */ >         tpm_buf_append_u8(&buf, TPM2_SE_HMAC); >   > @@ -1021,10 +1029,13 @@ int tpm2_start_auth_session(struct tpm_chip > *chip) >   >         tpm_buf_destroy(&buf); >   > -       if (rc) > -               goto out; > +       if (rc == TPM2_RC_SUCCESS) { > +               chip->auth = auth; > +               return 0; > +       } >   > - out: > +err: > +       kfree(auth); >         return rc; >  } >  EXPORT_SYMBOL(tpm2_start_auth_session); > @@ -1371,10 +1382,6 @@ int tpm2_sessions_init(struct tpm_chip *chip) >         if (rc) >                 return rc; >   > -       chip->auth = kmalloc(sizeof(*chip->auth), GFP_KERNEL); > -       if (!chip->auth) > -               return -ENOMEM; > - >         return rc; >  } >  #endif /* CONFIG_TCG_TPM2_HMAC */ Other than the comment above Reviewed-by: James Bottomley