From: Brian Gerst <brgerst@gmail.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>, "H . Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Linus Torvalds <torvalds@linuxfoundation.org>,
Brian Gerst <brgerst@gmail.com>
Subject: [PATCH 0/3] Reject setting system segments from userspace
Date: Wed, 13 Dec 2023 11:34:40 -0500 [thread overview]
Message-ID: <20231213163443.70490-1-brgerst@gmail.com> (raw)
Michal noted[1] that on systems that support UMIP, the instruction
decoder can be tricked into leaking the address of the TSS or LDT by
using ptrace to set the SS segment to a system segment index. Prevent
this from happening by rejecting attempts to use a system segment in the
ptrace and sigreturn syscalls.
[1] https://lore.kernel.org/lkml/20231206004654.2986026-1-mhal@rbox.co/
Brian Gerst (3):
x86: Move TSS and LDT to end of the GDT
x86/ptrace: Reject system segements
x86/sigreturn: Reject system segements
arch/x86/include/asm/segment.h | 44 ++++++++++++++++++++++++----------
arch/x86/kernel/ptrace.c | 12 ++--------
arch/x86/kernel/signal_32.c | 4 ++++
arch/x86/kernel/signal_64.c | 4 ++++
4 files changed, 42 insertions(+), 22 deletions(-)
base-commit: 3d626e0a7be7ddb635791fee18cb40631bc1d0b3
--
2.43.0
next reply other threads:[~2023-12-13 16:34 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-13 16:34 Brian Gerst [this message]
2023-12-13 16:34 ` [PATCH 1/3] x86: Move TSS and LDT to end of the GDT Brian Gerst
2023-12-13 18:51 ` Linus Torvalds
2023-12-13 19:08 ` Linus Torvalds
2023-12-16 18:24 ` Vegard Nossum
2023-12-16 18:40 ` Linus Torvalds
2023-12-17 21:09 ` H. Peter Anvin
2023-12-13 16:34 ` [PATCH 2/3] x86/ptrace: Reject system segements Brian Gerst
2023-12-13 16:34 ` [PATCH 3/3] x86/sigreturn: " Brian Gerst
2023-12-13 18:54 ` Linus Torvalds
2023-12-17 21:07 ` H. Peter Anvin
2023-12-17 21:40 ` Linus Torvalds
2023-12-17 21:45 ` H. Peter Anvin
2023-12-18 8:31 ` Li, Xin3
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