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 3896F196C7C; Tue, 26 Aug 2025 13:13:13 +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=1756213995; cv=none; b=HR0//YwGzwuNh9jDfLRHbVmNwkQRKSMXaYCeZy4DvVeB7gxZ+b8DvyFvNMCnTByIBT8nLtz4WXTt8bD1bmFTzOg3pJvGuFiMdnWHoqnmm3YDC+mb62ch1pkJUqnc/f8nUvqROLidbxTfdehCCvHPX+D+VrkWUPi2Zn8x12tl5Wg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756213995; c=relaxed/simple; bh=yFQvfDsTUq0CHMjirH+5N0IvEXFvwRS7+w7s10iKyzs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ASXSYJlz3dWy4RrlsMxz2g4VjfrULnjJt6j6ARSBgqCxhw6lM+SV+C0eDXe23f+w/Eju0jxEzUqA/D7eBn3B+Ftr3gzENfdvG2NiqtpRjSm5sH43CoI4i/yJu5rbo0pKUZuyHWqjAqc6+OxZIMmGoZMzW81ni9OEGGUxterSd9Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TZDnLYcp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="TZDnLYcp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D2C5C4CEF1; Tue, 26 Aug 2025 13:13:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756213993; bh=yFQvfDsTUq0CHMjirH+5N0IvEXFvwRS7+w7s10iKyzs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TZDnLYcpniVEjDi0phFagj/QZdB3Me06WRmqMAHww5NwzpMoT8JXiUvB5gmwrBnll FQJ1ylFkmY0+cBblc7+1oitx4bFkbWFsrpiD9Knet6LoBfhQqzXpoGvXmGWBQngKY+ PeZGN/UlpfOpQp0+y7SYYbweOHOBU9X5lfsOHq+o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Simcha Kosman , Kees Cook , Ankit Soni , Joerg Roedel , Sasha Levin Subject: [PATCH 6.6 558/587] iommu/amd: Avoid stack buffer overflow from kernel cmdline Date: Tue, 26 Aug 2025 13:11:47 +0200 Message-ID: <20250826111007.220420142@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110952.942403671@linuxfoundation.org> References: <20250826110952.942403671@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kees Cook [ Upstream commit 8503d0fcb1086a7cfe26df67ca4bd9bd9e99bdec ] While the kernel command line is considered trusted in most environments, avoid writing 1 byte past the end of "acpiid" if the "str" argument is maximum length. Reported-by: Simcha Kosman Closes: https://lore.kernel.org/all/AS8P193MB2271C4B24BCEDA31830F37AE84A52@AS8P193MB2271.EURP193.PROD.OUTLOOK.COM Fixes: b6b26d86c61c ("iommu/amd: Add a length limitation for the ivrs_acpihid command-line parameter") Signed-off-by: Kees Cook Reviewed-by: Ankit Soni Link: https://lore.kernel.org/r/20250804154023.work.970-kees@kernel.org Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/amd/init.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 2e7a12f30651..431cea41df2a 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -3625,7 +3625,7 @@ static int __init parse_ivrs_acpihid(char *str) { u32 seg = 0, bus, dev, fn; char *hid, *uid, *p, *addr; - char acpiid[ACPIID_LEN] = {0}; + char acpiid[ACPIID_LEN + 1] = { }; /* size with NULL terminator */ int i; addr = strchr(str, '@'); @@ -3651,7 +3651,7 @@ static int __init parse_ivrs_acpihid(char *str) /* We have the '@', make it the terminator to get just the acpiid */ *addr++ = 0; - if (strlen(str) > ACPIID_LEN + 1) + if (strlen(str) > ACPIID_LEN) goto not_found; if (sscanf(str, "=%s", acpiid) != 1) -- 2.50.1