From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 449091DDC0F; Thu, 10 Apr 2025 12:37:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744288666; cv=none; b=g+0l3QZMv0RLiS3PDQNCkpvjv+h+A4xmshnVvvp17lgiU2PrfSiy3nse1qXdnaT2dFiLtF1RYFOqcMCqVknKLJR6WbV+TYdW23apsjrd2rDJLpFV6HUW8r9ChFMvCcwRawQK0YZPPVOCnGpOqVXJbgPrWU/WJTY6w1HJg279IOg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744288666; c=relaxed/simple; bh=sPKm1/Nz6ZhOYtb/EBIrtiQ37Zx68yFWZK7cGLk4dIM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XFbKLjHDFYfqq6T8jbKr1sOsj8HwsnP/gx6auULloVn69Zpx0u/0pg1lW0LxRxA1XVijT2LqpmjkprLNq9zUjsHpczJEFhaaAB86dH/Wget9zuoA4X4yPlW4SIJehLKPss+Wj4cnA4VpohsbAUZ+y8sXUBL8/mzzXocfX532voE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bPe4nNb8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bPe4nNb8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E857C4CEDD; Thu, 10 Apr 2025 12:37:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744288664; bh=sPKm1/Nz6ZhOYtb/EBIrtiQ37Zx68yFWZK7cGLk4dIM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bPe4nNb8Rj61smw7NSryO5eHHvcfvGZXPo7sfzrPFef+EufqQdBpgcc10lb7/l7Hv 2OTZlHzAMbjjYiKnPGX2X77h4lH8D7qyRBToXyX64l8+Z9/ykI0bS+4owY1ZSM1Y+9 D/qayDHpmxXH9a1dUkAREFQmMtPV7OI494avInjBqwRnxr1qksHuaBmhbhjUfc+DgG ukWlCK5lnFU2a5AJifYQlEkn9hcd+5wnzGe2Ba/fMwn/RP1/+FbcTnizxxzQ7KMrDK aRtgNjMoA5tUORBscXVM56MfHNUstljCEHfUDH73q+iRawMJWv8fGNuARKuf6ApNtX mrIaCBhFtKxyQ== Date: Thu, 10 Apr 2025 15:37:40 +0300 From: Jarkko Sakkinen To: Purva Yeshi Cc: peterhuewe@gmx.de, jgg@ziepe.ca, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] char: tpm: tpm-buf: Add sanity check fallback in read helpers Message-ID: References: <20250410103442.17746-1-purvayeshi550@gmail.com> Precedence: bulk X-Mailing-List: linux-integrity@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250410103442.17746-1-purvayeshi550@gmail.com> On Thu, Apr 10, 2025 at 04:04:42PM +0530, Purva Yeshi wrote: > Fix Smatch-detected issue: > > drivers/char/tpm/tpm-buf.c:208 tpm_buf_read_u8() error: > uninitialized symbol 'value'. > drivers/char/tpm/tpm-buf.c:225 tpm_buf_read_u16() error: > uninitialized symbol 'value'. > drivers/char/tpm/tpm-buf.c:242 tpm_buf_read_u32() error: > uninitialized symbol 'value'. > > Zero-initialize the return values in tpm_buf_read_u8(), > tpm_buf_read_u16(), and tpm_buf_read_u32() to guard against > uninitialized data in case of a boundary overflow. > > Add defensive initialization ensures the return values are > always defined, preventing undefined behavior if the unexpected > happens. > > Signed-off-by: Purva Yeshi > --- > V1 - https://lore.kernel.org/all/20250409205536.210202-1-purvayeshi550@gmail.com/ > V2 - Update commit message to clarify patch adds a sanity check > > drivers/char/tpm/tpm-buf.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/char/tpm/tpm-buf.c b/drivers/char/tpm/tpm-buf.c > index e49a19fea3bd..dc882fc9fa9e 100644 > --- a/drivers/char/tpm/tpm-buf.c > +++ b/drivers/char/tpm/tpm-buf.c > @@ -201,7 +201,7 @@ static void tpm_buf_read(struct tpm_buf *buf, off_t *offset, size_t count, void > */ > u8 tpm_buf_read_u8(struct tpm_buf *buf, off_t *offset) > { > - u8 value; > + u8 value = 0; > > tpm_buf_read(buf, offset, sizeof(value), &value); > > @@ -218,7 +218,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u8); > */ > u16 tpm_buf_read_u16(struct tpm_buf *buf, off_t *offset) > { > - u16 value; > + u16 value = 0; > > tpm_buf_read(buf, offset, sizeof(value), &value); > > @@ -235,7 +235,7 @@ EXPORT_SYMBOL_GPL(tpm_buf_read_u16); > */ > u32 tpm_buf_read_u32(struct tpm_buf *buf, off_t *offset) > { > - u32 value; > + u32 value = 0; > > tpm_buf_read(buf, offset, sizeof(value), &value); > > -- > 2.34.1 > > It's good and I think this change is appropriate overall! Reviewed-by: Jarkko Sakkinen BR, Jarkko