From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4EAFC31AA87 for ; Thu, 17 Sep 2026 00:23:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789604616; cv=none; b=FulKKEi4/XsoSSZEITR90G6uvBM/Ofn18pFRqYyJxKq/DEwbi0dyGAzoISj1sYQlD58+0MOHp4oUV6zRlx1q7LOk5rmEX2+64LL9tdCTobZwYUsAzqbJXOdVtWuUG766rWFF70a2IFU+1UB+2hsP8BKhpv5vhyih0s83Gm7RV5Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789604616; c=relaxed/simple; bh=QpDdcSnidsU2zeT85ZzQmT7vYMazwTC5RAWGMIhrVIY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=Szk5i73jvBneAdwPAtaLzC12TzCIpUNDc2s/apC5rJALOqHw+/36aSbkekyyTNBmLwnIT1YKkJlSkGJmJjA1SmmKZNjBL/eqlMgBdJC2CbDPc6ZbvL5qKryxEkIubYtZ4pexUkn+GXhfPvEPKfh3POOwSyNAtCiDouLEmLH2gXU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k6JycS3o; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k6JycS3o" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96BCB1F008A2; Thu, 17 Sep 2026 00:23:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789604613; bh=McaKO0yHOxz0y4KcMiZNfILTWJHJOqO2DVoFelFO74s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=k6JycS3of59rxdBiglixB5HNPd6Dn5sh6zdLBA0Xh36pf/UBbkl5Jj9dmgGswxBxJ WnCNiCLj6IXDccT/fv9yOgekTIpVqSP+aZDJiGVTJCuXhDOp1NWY4HfVOHb7CeukNN GpVQks5mFfFESbXc+hEaLf5Gq2ysKEHS+ZgNc6JfsLflpz+tm6XDQqQ/W3SPsHpi1C BsV8ASpurk7btY1td0fXbBWGXIM4kKSt3hbA5N1V43x1CkFCWOhLljdqvbpTRF38C4 eLii2d0P06xYKOkM1NL5zO533NPhayV98Qub2ZtOdmjZWRWOWdOsAaFIlLPTLiLOPO /20AVW4FNymdw== From: Kees Cook To: Bill Wendling Cc: Kees Cook , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Thorsten Blum , Shivaprasad G Bhat , linuxppc-dev@lists.ozlabs.org, Steven Rostedt , Andy Shevchenko , linux-hardening@vger.kernel.org Subject: [PATCH 6/7] powerpc/papr_scm: Return the string length from the sysfs show functions Date: Wed, 16 Sep 2026 17:23:18 -0700 Message-Id: <20260917002333.2306346-6-kees@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260917002312.i.923-kees@kernel.org> References: <20260917002312.i.923-kees@kernel.org> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Developer-Signature: v=1; a=openpgp-sha256; l=1593; i=kees@kernel.org; h=from:subject; bh=QpDdcSnidsU2zeT85ZzQmT7vYMazwTC5RAWGMIhrVIY=; b=owGbwMvMwCVmps19z/KJym7G02pJDFmrjb7xzWJ+eWth43WfdTVuE3LK7j29oPS8L/2ATsD8X 11HnVKPdpSyMIhxMciKKbIE2bnHuXi8bQ93n6sIM4eVCWQIAxenAEzEgZGRYQmToYjh5TNi1p8v Lo5aUbhrcnqf9ePdj0ISGJdm8/p+/s7wz3bxHJ33y6XabPcZNZqWmF+9M/nBPZ7SDRc3n4yav+7 3QjYA X-Developer-Key: i=kees@kernel.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Content-Transfer-Encoding: 8bit perf_stats_show() and flags_show() build their output with a seq_buf and return seq_buf_used(), which may include the trailing NUL byte when the seq_buf has overflowed. Use seq_buf_strlen() instead. Build tested ARCH=powerpc ppc64_defconfig with GCC powerpc64-linux-gnu 16.1.0: arch/powerpc/platforms/pseries/papr_scm.o Assisted-by: LLM Signed-off-by: Kees Cook --- Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Nicholas Piggin Cc: "Christophe Leroy (CS GROUP)" Cc: "Uwe Kleine-König" Cc: Thorsten Blum Cc: Shivaprasad G Bhat Cc: --- arch/powerpc/platforms/pseries/papr_scm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index 75da96c08cdd..6c87c8b4de8e 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/arch/powerpc/platforms/pseries/papr_scm.c @@ -1108,7 +1108,7 @@ static ssize_t perf_stats_show(struct device *dev, free_stats: kfree(stats); - return rc ? rc : (ssize_t)seq_buf_used(&s); + return rc ? rc : (ssize_t)seq_buf_strlen(&s); } static DEVICE_ATTR_ADMIN_RO(perf_stats); @@ -1150,7 +1150,7 @@ static ssize_t flags_show(struct device *dev, if (seq_buf_used(&s)) seq_buf_printf(&s, "\n"); - return seq_buf_used(&s); + return seq_buf_strlen(&s); } DEVICE_ATTR_RO(flags); -- 2.34.1