linux-kernel - [PATCH v2 4/5] x86/uapi: Stop leaking kconfig references to userspace

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20260112-headers_install-config-leak-v2-4-4d8084444603@linutronix.de>
Date: Mon, 12 Jan 2026 08:58:32 +0100
From: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
To: Vineet Gupta <vgupta@...nel.org>, Russell King <linux@...linux.org.uk>, 
 Dinh Nguyen <dinguyen@...nel.org>, Thomas Gleixner <tglx@...utronix.de>, 
 Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, 
 Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org, 
 "H. Peter Anvin" <hpa@...or.com>
Cc: linux-snps-arc@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 linux-arm-kernel@...ts.infradead.org, Arnd Bergmann <arnd@...db.de>, 
 Thomas Weißschuh <thomas.weissschuh@...utronix.de>
Subject: [PATCH v2 4/5] x86/uapi: Stop leaking kconfig references to
 userspace

UAPI headers are not supposed to leak references to kconfig symbols.
These won't be set when building userspace. Hide the kconfig reference
behind 'if defined(__KERNEL__)', so it will be stripped by
headers_install.sh. The result for userspace will be the same, but the
exceptions in headers_install.sh can also be removed.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@...utronix.de>

---
There is no point in exposing AT_VECTOR_SIZE_ARCH in the UAPI in any
case and I have another series in the works to get rid of it completely.
---
 arch/x86/include/uapi/asm/auxvec.h | 2 +-
 scripts/headers_install.sh         | 2 --
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/include/uapi/asm/auxvec.h b/arch/x86/include/uapi/asm/auxvec.h
index 6beb55bbefa4..bdde9e18f94e 100644
--- a/arch/x86/include/uapi/asm/auxvec.h
+++ b/arch/x86/include/uapi/asm/auxvec.h
@@ -11,7 +11,7 @@
 #define AT_SYSINFO_EHDR		33

 /* entries in ARCH_DLINFO: */
-#if defined(CONFIG_IA32_EMULATION) || !defined(CONFIG_X86_64)
+#if defined(__KERNEL__) && (defined(CONFIG_IA32_EMULATION) || !defined(CONFIG_X86_64))
 # define AT_VECTOR_SIZE_ARCH 3
 #else /* else it's non-compat x86-64 */
 # define AT_VECTOR_SIZE_ARCH 2
diff --git a/scripts/headers_install.sh b/scripts/headers_install.sh
index 613f400a67d1..1301ba68d772 100755
--- a/scripts/headers_install.sh
+++ b/scripts/headers_install.sh
@@ -70,8 +70,6 @@ configs=$(sed -e '
 #
 # The format is <file-name>:<CONFIG-option> in each line.
 config_leak_ignores="
-arch/x86/include/uapi/asm/auxvec.h:CONFIG_IA32_EMULATION
-arch/x86/include/uapi/asm/auxvec.h:CONFIG_X86_64
 "

 for c in $configs

-- 
2.52.0