[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1334267284-19166-14-git-send-email-wad@chromium.org>
Date: Thu, 12 Apr 2012 16:48:03 -0500
From: Will Drewry <wad@...omium.org>
To: linux-kernel@...r.kernel.org
Cc: linux-man@...r.kernel.org,
linux-security-module@...r.kernel.org,
linux-arch@...r.kernel.org,
linux-doc@...r.kernel.org,
kernel-hardening@...ts.openwall.com,
netdev@...r.kernel.org,
x86@...nel.org,
arnd@...db.de,
davem@...emloft.net,
hpa@...or.com,
mingo@...hat.com,
oleg@...hat.com,
peterz@...radead.org,
rdunlap@...otime.net,
mcgrathr@...omium.org,
tglx@...utronix.de,
luto@....edu,
eparis@...hat.com,
serge.hallyn@...onical.com,
djm@...drot.org,
scarybeasts@...il.com,
indan@....nu,
pmoore@...hat.com,
akpm@...ux-foundation.org,
corbet@....net,
eric.dumazet@...il.com,
markus@...omium.org,
coreyb@...ux.vnet.ibm.com,
keescook@...omium.org,
jmorris@...ei.org,
Will Drewry <wad@...omium.org>
Subject: [PATCH v18 14/15] x86: Enable HAVE_ARCH_SECCOMP_FILTER
Enable support for seccomp filter on x86:
- syscall_get_arch()
- syscall_get_arguments()
- syscall_rollback()
- syscall_set_return_value()
- SIGSYS siginfo_t support
- secure_computing is called from a ptrace_event()-safe context
- secure_computing return value is checked (see below).
SECCOMP_RET_TRACE and SECCOMP_RET_TRAP may result in seccomp needing to
skip a system call without killing the process. This is done by
returning a non-zero (-1) value from secure_computing. This change
makes x86 respect that return value.
To ensure that minimal kernel code is exposed, a non-zero return value
results in an immediate return to user space (with an invalid syscall
number).
Signed-off-by: Will Drewry <wad@...omium.org>
Reviewed-by: H. Peter Anvin <hpa@...or.com>
Acked-by: Eric Paris <eparis@...hat.com>
v18: rebase and tweaked change description, acked-by
v17: added reviewed by and rebased
v..: all rebases since original introduction.
---
arch/x86/Kconfig | 1 +
arch/x86/kernel/ptrace.c | 7 ++++++-
2 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1d14cc6..3a41c44 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -82,6 +82,7 @@ config X86
select ARCH_HAVE_NMI_SAFE_CMPXCHG
select GENERIC_IOMAP
select DCACHE_WORD_ACCESS if !DEBUG_PAGEALLOC
+ select HAVE_ARCH_SECCOMP_FILTER
config INSTRUCTION_DECODER
def_bool (KPROBES || PERF_EVENTS)
diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 685845c..13b1990 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -1480,7 +1480,11 @@ long syscall_trace_enter(struct pt_regs *regs)
regs->flags |= X86_EFLAGS_TF;
/* do the secure computing check first */
- secure_computing(regs->orig_ax);
+ if (secure_computing(regs->orig_ax)) {
+ /* seccomp failures shouldn't expose any additional code. */
+ ret = -1L;
+ goto out;
+ }
if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
ret = -1L;
@@ -1505,6 +1509,7 @@ long syscall_trace_enter(struct pt_regs *regs)
regs->dx, regs->r10);
#endif
+out:
return ret ?: regs->orig_ax;
}
--
1.7.5.4
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
