linux-kernel - [PATCH AUTOSEL 4.19 3/5] PNP: ACPI: fix fortify warning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Mon, 15 Jan 2024 19:15:23 -0500
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Dmitry Antipov <dmantipov@...dex.ru>,
	Kees Cook <keescook@...omium.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
	Sasha Levin <sashal@...nel.org>,
	rafael@...nel.org,
	linux-acpi@...r.kernel.org,
	linux-hardening@...r.kernel.org
Subject: [PATCH AUTOSEL 4.19 3/5] PNP: ACPI: fix fortify warning

From: Dmitry Antipov <dmantipov@...dex.ru>

[ Upstream commit ba3f5058db437d919f8468db50483dd9028ff688 ]

When compiling with gcc version 14.0.0 20231126 (experimental)
and CONFIG_FORTIFY_SOURCE=y, I've noticed the following:

In file included from ./include/linux/string.h:295,
                 from ./include/linux/bitmap.h:12,
                 from ./include/linux/cpumask.h:12,
                 from ./arch/x86/include/asm/paravirt.h:17,
                 from ./arch/x86/include/asm/cpuid.h:62,
                 from ./arch/x86/include/asm/processor.h:19,
                 from ./arch/x86/include/asm/cpufeature.h:5,
                 from ./arch/x86/include/asm/thread_info.h:53,
                 from ./include/linux/thread_info.h:60,
                 from ./arch/x86/include/asm/preempt.h:9,
                 from ./include/linux/preempt.h:79,
                 from ./include/linux/spinlock.h:56,
                 from ./include/linux/mmzone.h:8,
                 from ./include/linux/gfp.h:7,
                 from ./include/linux/slab.h:16,
                 from ./include/linux/resource_ext.h:11,
                 from ./include/linux/acpi.h:13,
                 from drivers/pnp/pnpacpi/rsparser.c:11:
In function 'fortify_memcpy_chk',
    inlined from 'pnpacpi_parse_allocated_vendor' at drivers/pnp/pnpacpi/rsparser.c:158:3,
    inlined from 'pnpacpi_allocated_resource' at drivers/pnp/pnpacpi/rsparser.c:249:3:
/include/linux/fortify-string.h:588:25: warning: call to '__read_overflow2_field'
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Wattribute-warning]
  588 |                         __read_overflow2_field(q_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

According to the comments in include/linux/fortify-string.h, 'memcpy()',
'memmove()' and 'memset()' must not be used beyond individual struct
members to ensure that the compiler can enforce protection against
buffer overflows, and, IIUC, this also applies to partial copies from
the particular member ('vendor->byte_data' in this case). So it should
be better (and safer) to do both copies at once (and 'byte_data' of
'struct acpi_resource_vendor_typed' seems to be a good candidate for
'__counted_by(byte_length)' as well).

Signed-off-by: Dmitry Antipov <dmantipov@...dex.ru>
Reviewed-by: Kees Cook <keescook@...omium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/pnp/pnpacpi/rsparser.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c
index 43d8ed577e70..d8cee80e8df8 100644
--- a/drivers/pnp/pnpacpi/rsparser.c
+++ b/drivers/pnp/pnpacpi/rsparser.c
@@ -160,13 +160,13 @@ static int vendor_resource_matches(struct pnp_dev *dev,
 static void pnpacpi_parse_allocated_vendor(struct pnp_dev *dev,
 				    struct acpi_resource_vendor_typed *vendor)
 {
-	if (vendor_resource_matches(dev, vendor, &hp_ccsr_uuid, 16)) {
-		u64 start, length;
+	struct { u64 start, length; } range;
 
-		memcpy(&start, vendor->byte_data, sizeof(start));
-		memcpy(&length, vendor->byte_data + 8, sizeof(length));
-
-		pnp_add_mem_resource(dev, start, start + length - 1, 0);
+	if (vendor_resource_matches(dev, vendor, &hp_ccsr_uuid,
+				    sizeof(range))) {
+		memcpy(&range, vendor->byte_data, sizeof(range));
+		pnp_add_mem_resource(dev, range.start, range.start +
+				     range.length - 1, 0);
 	}
 }
 
-- 
2.43.0