From: Cong Wang <xiyou.wangcong@gmail.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Kees Cook <kees@kernel.org>,
linux-kernel@vger.kernel.org, Will Drewry <wad@chromium.org>,
Christian Brauner <brauner@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, Cong Wang <cwang@multikernel.io>
Subject: [PATCH v5 3/7] seccomp: add __NR_seccomp_* aliases for rt_sigreturn and clone/fork
Date: Sat, 4 Jul 2026 16:18:27 -0700 [thread overview]
Message-ID: <20260704231831.354543-4-xiyou.wangcong@gmail.com> (raw)
In-Reply-To: <20260704231831.354543-1-xiyou.wangcong@gmail.com>
From: Cong Wang <cwang@multikernel.io>
The existing __NR_seccomp_* aliases name only the syscalls strict mode
allows (read/write/exit/sigreturn). SEND_REDIRECT needs to recognise a
few more so it can refuse to redirect them; add aliases for those,
following the same arch-overridable pattern that keeps arch-specific
numbers out of generic seccomp code:
- __NR_seccomp_rt_sigreturn{,_32}: sigreturn and rt_sigreturn are
distinct numbers on 32-bit/compat, so both must be nameable. The
generic default aliases rt_sigreturn to the plain sigreturn number,
a harmless duplicate on arches that do not distinguish the two.
- __NR_seccomp_clone{,3}{,_32}, __NR_seccomp_{,v}fork{,_32}: the
task-creation family. An arch lacking a syscall, or without a
distinct compat number, maps it to -1, which is never a valid
syscall number and so never matches.
x86 supplies the ia32 compat numbers. No functional change; the aliases
are consumed by the SEND_REDIRECT denylist in a later commit.
Assisted-by: Claude:claude-opus-4.8
Signed-off-by: Cong Wang <cwang@multikernel.io>
---
arch/x86/include/asm/seccomp.h | 6 +++++
include/asm-generic/seccomp.h | 45 ++++++++++++++++++++++++++++++++++
2 files changed, 51 insertions(+)
diff --git a/arch/x86/include/asm/seccomp.h b/arch/x86/include/asm/seccomp.h
index 42bcd42d70d1..c95c00b8927c 100644
--- a/arch/x86/include/asm/seccomp.h
+++ b/arch/x86/include/asm/seccomp.h
@@ -6,6 +6,7 @@
#ifdef CONFIG_X86_32
#define __NR_seccomp_sigreturn __NR_sigreturn
+#define __NR_seccomp_rt_sigreturn __NR_rt_sigreturn
#endif
#ifdef CONFIG_COMPAT
@@ -14,6 +15,11 @@
#define __NR_seccomp_write_32 __NR_ia32_write
#define __NR_seccomp_exit_32 __NR_ia32_exit
#define __NR_seccomp_sigreturn_32 __NR_ia32_sigreturn
+#define __NR_seccomp_rt_sigreturn_32 __NR_ia32_rt_sigreturn
+#define __NR_seccomp_clone_32 __NR_ia32_clone
+#define __NR_seccomp_clone3_32 __NR_ia32_clone3
+#define __NR_seccomp_fork_32 __NR_ia32_fork
+#define __NR_seccomp_vfork_32 __NR_ia32_vfork
#endif
#ifdef CONFIG_X86_64
diff --git a/include/asm-generic/seccomp.h b/include/asm-generic/seccomp.h
index 6b6f42bc58f9..3c63ce888225 100644
--- a/include/asm-generic/seccomp.h
+++ b/include/asm-generic/seccomp.h
@@ -25,6 +25,51 @@
#ifndef __NR_seccomp_sigreturn
#define __NR_seccomp_sigreturn __NR_rt_sigreturn
#endif
+#if defined(CONFIG_COMPAT) && !defined(__NR_seccomp_rt_sigreturn_32)
+#define __NR_seccomp_rt_sigreturn_32 __NR_seccomp_sigreturn_32
+#endif
+#ifndef __NR_seccomp_rt_sigreturn
+#define __NR_seccomp_rt_sigreturn __NR_seccomp_sigreturn
+#endif
+
+#ifndef __NR_seccomp_clone
+#define __NR_seccomp_clone __NR_clone
+#endif
+#ifndef __NR_seccomp_clone3
+#ifdef __NR_clone3
+#define __NR_seccomp_clone3 __NR_clone3
+#else
+#define __NR_seccomp_clone3 (-1)
+#endif
+#endif
+#ifndef __NR_seccomp_fork
+#ifdef __NR_fork
+#define __NR_seccomp_fork __NR_fork
+#else
+#define __NR_seccomp_fork (-1)
+#endif
+#endif
+#ifndef __NR_seccomp_vfork
+#ifdef __NR_vfork
+#define __NR_seccomp_vfork __NR_vfork
+#else
+#define __NR_seccomp_vfork (-1)
+#endif
+#endif
+#ifdef CONFIG_COMPAT
+#ifndef __NR_seccomp_clone_32
+#define __NR_seccomp_clone_32 (-1)
+#endif
+#ifndef __NR_seccomp_clone3_32
+#define __NR_seccomp_clone3_32 (-1)
+#endif
+#ifndef __NR_seccomp_fork_32
+#define __NR_seccomp_fork_32 (-1)
+#endif
+#ifndef __NR_seccomp_vfork_32
+#define __NR_seccomp_vfork_32 (-1)
+#endif
+#endif /* CONFIG_COMPAT */
#ifdef CONFIG_COMPAT
#ifndef get_compat_mode1_syscalls
--
2.43.0
next prev parent reply other threads:[~2026-07-04 23:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-04 23:18 [PATCH v5 0/7] seccomp: non-cooperative pinned-memfd argument redirect Cong Wang
2026-07-04 23:18 ` [PATCH v5 1/7] mm: add __do_mmap() and vm_mmap_remote()/vm_munmap_remote() Cong Wang
2026-07-04 23:18 ` [PATCH v5 2/7] seccomp: introduce SECCOMP_IOCTL_NOTIF_PIN_INSTALL Cong Wang
2026-07-04 23:18 ` Cong Wang [this message]
2026-07-04 23:18 ` [PATCH v5 4/7] seccomp: add kernel-installed pinned-memfd redirect Cong Wang
2026-07-04 23:18 ` [PATCH v5 5/7] seccomp: re-validate a redirected syscall against outer filters Cong Wang
2026-07-04 23:18 ` [PATCH v5 6/7] docs/seccomp: document pinned-memfd redirect ioctls Cong Wang
2026-07-04 23:18 ` [PATCH v5 7/7] selftests/seccomp: cover non-cooperative pinned-memfd install Cong Wang
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